text:
|Publication number
|Publication type
|Application number
|Publication date
|Jul 23, 1991
|Filing date
|Jul 11, 1990
|Priority date
|Oct 19, 1988
|Fee status
|Also published as
|Publication number
|Toshifumi Fukuyama
|Original Assignee
|Astex Co., Ltd., Takenaka Electronic Ind. Co., Ltd.
|Export Citation
|BiBTeX, EndNote, RefMan
|Patent Citations (1), Referenced by (3), Classifications (17), Legal Events (6)
|External Links: USPTO, USPTO Assignment, Espacenet
This application is a division of application Ser. No. 421,529, filed on Oct. 13, 1989.
1) Field of the Invention
This invention relates to an integrated circuit used in a photoelectric switch whose principal components, namely, light-receiving elements, an amplifier circuit and their control portions, are formed on an integrated circuit (IC) with reductions in size and pin requirements provided through multifunction circuit arrangements. Also disclosed are improvements in external electrical circuits designed to function cooperatively with such ICs so as to support such multi-function capabilities.
2) Description of the Prior Art
Heretofore, there have mainly been known photoelectric switches of a pulse modulation type in which a photoelectric current produced by a light-receiving element is amplified when a light-emitting diode (LED) is pulse-illuminated to produce pulsating light having a predetermined wavelength which is received as the medium to be detected are only outputted as detection signals. When a detection output is produced in response to pulses of a predetermined level or higher, a light-emitting diode or the like is illuminated in order to make one aware of its output information.
To provide greater flexibility when mounted on machines in operational applications, there is a strong demand for a smaller photoelectric switch. It is therefore desirable to form photodiodes on the integrated circuit (IC) and to reduce the overall size of the IC itself. If one attempts to form the photodiodes and other circuits as an integrated unit and also enhance functions using prior art techniques, the number of IC terminals increases, so that the area necessary for mounting the IC becomes larger than that of the IC chip even if the area of the IC chip itself can be reduced. As a consequence, a contradiction arises in that on an overall basis the photoelectric switch cannot be significantly reduced in size. In addition, a problem arises in that the number of bonding wires, which connect the pins to the IC chip, increases as the number of the pins increase so that there is a high possibility of breaking of the bonding wires, resulting in poorer reliability. Manufacturing cost may also increase due to an increase in the number of steps necessary with additional pin corrections.
In addition, while advances in integrated circuits have improved design flexibility and performance, application to photoelectric switches has been limited. In integrated circuits for photoelectric switches, which are now widespread, light-receiving elements, such as photodiodes for converting light into electrical signals, and their control portions are arranged separately from amplifiers and other circuits. In addition, since it is common in the present art that only one function is assigned to each IC pin correction, even if one attempts to form the photodiodes and the amplifiers in an integrated unit, the number of the pins necessary becomes significantly greater.
Thus, in the conventional photoelectric switch even though multi-function operation may be provided, a terminal for the detection output is provided separately from an output terminal for the light-emitting diode. Accordingly, interconnection of the various circuits requires additional electrical connections. In addition, when an output transistor is unintentionally short-circuited upon wiring, it is apt to result in the failure of the output transistor. In order to avoid such a breakdown, a short-circuit protection circuit is normally provided. However, this circuit is arranged separately from a detection output circuit. Where a further failure such as a disconnection occurs in a light-receiving circuit around a photoelectric element, an amplifier, etc., a self-diagnosing output is sometimes used in order to give this information to an external device. However, a circuit for the self-diagnosing output is also provided in a separated manner and input/output pins are arranged separately from each other.
When a photoelectric switch is employed as a reflection type, a train of pulses is generated by an oscillator so as to flash a projector (a light-emitting diode) at a predetermined time interval and hence to flash the projector at this repetitive period. An interconnected projector means is indispensable for a photoelectric switch of the reflection type, while a switch of a transmission type operates in cooperation with a separate light projector. Thus, it is not practical to flash the separated projector in a synchronized manner. Further, a reflection type photoelectric switch operates with a continuous stream of received photopulses while adjusting or synchronizing the periodicity of the projector with that of a light-receiving unit. On the other hand, in a transmission type photoelectric switch in which the projector is arrange separately rom the light-receiving unit it is difficult to adjust the periodicity of the projector with that of the light-receiving unit to provide synchronous operation. For this reason, a non-synchronous type is normally used. If one attempts to produce a general-purpose photoelectric switch, a circuit capable of turning the projector on and off and of selecting either one of the synchronous and non-synchronous operation modes must be provided. In order to do this, a circuit for turning the projector on and off and a circuit for performing the changeover of the synchronous and nonsynchronous operation modes have heretofore been provided in a separated manner. Accordingly, separate input/output pins have also been provided.
Further, a comparator determines whether or not a detection output exists. However, in some cases reliability cannot be assured, for example, in a factory where the atmospheric temperature varies, the level preset as a reference voltage within the comparator varies with such external conditions because of the temperature characteristics of the comparator. In order to avoid such an unreliable state, two voltages having proper levels above and below the reference voltage of the comparator are compared by another comparator to derive a stable state signal. A stable state signal is obtained when the level of the signal becomes equal to or greater than the voltage obtained by that comparison and may be indicated by a displaying means such as a light-emitting diode, for making an observer aware of such a state, whereby the reliability of operation can be monitored. In a reflection-type switch, light is incident upon the light-receiving element when light reflects from a detected object. Whereas, in a transmission type switch no light is incident upon the light receiving elements upon the detection of the object because of the absence of light caused by screening of the object upon detection. Basically, such conditions are just opposite to each other. In a combination switch for reflection or transmission applications it is therefore necessary to permit the changeover between an operational system ("light on") for illuminating an operation indicator upon incidence of light and a system ("dark on") for illuminating the indicator upon screening of light, in accordance with the conditions of actual use. However, in the conventional photoelectric switch, the two functions, i.e., the stable indication function and operation indicating switching function are set in a separated manner and their circuits are also separated from each other.
Furthermore, when the circuit determines whether an object exists, problems arise because of changes in the distance between the object and the light source and because of changes in the brightness of the light source itself. As a result, arrangements for amplifying photoelectric current for use with an active element may include a cumulative amplifying means and a differential amplifying means. However, differential amplifying means is unsuitable for a slight photoelectric current. It is preferable to adopt a high-accuracy differential amplifying means in the presence of a strong photoelectric current. Accordingly, an electric circuit is constructed such that both means can be changed over properly. In addition, an a.c. amplifier for performing amplification of a signal, to the extent that the signal can be processed by a detection circuit, is provided at a stage subsequent to a means for amplifying photoelectric current. It is further advantageous if the gain of the a.c. amplifier can be controlled. Therefore, the amplified signal is controlled by a gain controller but this control is carried out by a circuit different from the above-described amplifying means.
The circuit according to the present invention is designed to employ two light-receiving elements. In this case, two dimensional detection can be performed if the balance of sensitivity between the two light-receiving elements is caused to change, so that the distance to an object to be detected may be changed. For this purpose, it is preferable to provide a circuit for controlling the balance of sensitivity therebetween, but the number of pins becomes greater if such control is performed by means of other pins.
If one attempts to increase the number of functions with conventional circuit construction, the number of the pins is increased by the number of the functions, so that advantageous effects of having a smaller IC with high reliability must be sacrificed. In view of this, it would be desirable to determine ways to provide a number of functions for each pin in order to reduce the number of unnecessary pins, especially upon production of the photo IC.
It is therefore an object of this invention to provide an electric circuit for use in a photoelectric switch, which is capable of providing plural functions for each input/output pin and multi-function operation means of six pins in total, including the power pins.
It is another object of this invention to provide an electric circuit operative for producing a detection output suitable for an integrated circuit this circuit being designed to share a conductor used as a detection output pin and conductors used for an operation output from an operation indicating LED, for an input of a short-circuit protector, and for a self-diagnosing output for effecting plural functions with a single conductor.
It is further object of this invention to provide an electric circuit operative for generating an oscillating output suitable for an integrated circuit, said circuit being so designed that a projector is flashed by a series of pulses where a photoelectric switch is employed as a reflection type. The projector is not flashed where the photoelectric switch is used as a transmission type and a function for selecting operation of the photoelectric switch as a nonsynchronous type is effected using a single shared conductor. The two operation systems are suitably changed over by the use of a simple conductor.
It is a still further object of this invention to provide an electric circuit operative for generating a stable indication output. This circuit being of the type such that the connection between a stable indication output side and a circuit for producing a signal switchable for the operation of "light on" or "dark on" operation indicator is shared by a single conductor. Illuminating current which flows through a stable indicator, etc. is used as injection current which flows in said last-mentioned circuit, whose injection current is to be supplied to an integrated injection logic circuit.
It is a still further object of this invention to provide an electric circuit operative for outputting a received photo-output signal suitable for use in an integrated circuit, said circuit being so designed that the changeover of a means for amplifying photoelectric current, the adjustment in the balance of sensitivity of light-receiving elements and the gain control of an a.c. amplifier are carried out by a single variable resistor, so that multi-functions may be performed by a single conductor. In addition, a high-sensitivity electric circuit is also disclosed which is designed to output a received photo-signal under the control of a current responsive to essential functions of active elements.
The above and other objects, features and advantages of the present invention will become apparent from the following detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings.
The accompanying drawings show the preferred embodiments of the present invention.
FIG. 1 is a typical illustration showing an integrated electric circuit according to this invention, which is for use in a photoelectric switch;
FIG. 2 is a circuit diagram illustrating the manner of connection of an integrated circuit to an external circuit;
FIG 3. is a block diagram depicting the overall construction of the integrated circuit;
FIG. 4 is an electric circuit diagram showing a detection output circuit;
FIG. 5 is an electric circuit diagram depicting an oscillating output circuit;
FIG. 6 is an electric circuit diagram illustrating a stable indication output circuit;
FIG. 7 is a graph for describing the characteristics of current vs. voltages between a stable indication LED and a diode connected in series therewith;
FIG. 8 is an electric circuit diagram showing a light-receiving circuit according to one embodiment of this invention;
FIG. 9 is a graph for describing variations in tangential resistances of a diode;
FIG. 10 is an electric circuit diagram showing a light-receiving circuit according to a second embodiment;
FIG. 11 is a graph for describing the relationship between voltages depending upon the change in resistance of a variable resistor and received photo-output current;
FIG. 12 is a graph for illustrating frequency characteristics between the first embodiment and the second embodiment;
FIG. 13 is a circuit diagram showing the principle of the light-receiving circuit of the second embodiment;
FIG. 14 is a cross-sectional view depicting a stacked laminate structure of photodiodes employed in the second embodiment;
FIG. 15 is a circuit diagram of the photodiodes; and
FIG. 16 is a graph for describing photoelectric current produced by the photodiodes.
The preferred embodiments of the present invention will hereinafter be described with reference to the accompanying drawings.
FIG. 1 is a typical illustration showing an electric circuit formed as an integrated-circuit (hereinafter abbreviated "IC") according to the present invention, which is suitable for use in a photoelectric switch. Two photodiodes are provided as detection means to collectively bring various multi-functions into operation utilizing only six terminals. These terminals are connected to terminal pins a to f by means of bonding wires. The photoelectric switch according to the present invention is composed of circuitry internal to said IC and an associated external support circuit.
FIG. 2 is a circuit diagram showing the manner that the electric circuit, according to the present invention, is connected to external elements via pins a to f so as to form a photoelectric switch of the reflection type. Where the elements of the IC and the external circuit are illustrated, the portions designated with capital letters will hereinafter identify external elements, while those designated with small letters will hereinafter identify internal elements to the IC. As used here, the symbol LED designates a light-emitting diode, symbol LED1 designates a projection-type light-emitting diode, symbol LED2 designates a stable indication light-emitting diode which is for exhibiting whether outputs are in a stable state, and symbol LED3 designates a light-emitting diode used for exhibiting whether detection output exist. The operation indicating LED3 operates to suitably display the operation type, namely, either the state of "dark on" which emits light upon interruption of light, and the state of "light on", which emits light in the presence of incident light, the type of operation being selected by means of operation mode switch SW1, which connects to LED2. Symbol VR is a variable resistor which is used for amplifying current of photodiodes PD1 and PD2 and for controlling their operations, for performing the adjustment in the balance of sensitivity of the photodiodes and the gain control of an amplifier. Symbol C1 is a ripple smoothing capacitor for reducing noise from the outside and controlling noise produced internally. A further description will be provided of the functions of the individual pins a to f.
Pin a is used as a detection output terminal and outputs a detection signal therefrom. In addition, pin a controls LED3 and a self-diagnosing output terminal for determining whether the internal circuit of the IC is in a normal condition. In addition to the above functions, pin a has a short-circuit protection function in order to prevent an output transistor Q2 from breaking down due to misconnection upon attachment of wires, i.e., conductors. Pin b is a synchronous pulse train output terminal which is used for illuminating LED1 in synchronization with light-receiving timings of the photodiodes PD1 and PD2. In view of the fact that pin b is only used during the light-reception periods of the light sensitive photo-diodes, pin b also used for the function of synchronization/nonsynchronization switching. Pin c is a stable indication terminal used for controlling LED2. Pin c also has a function for suitably changing the operation of LED3 from the state of "dark on" to the state of "light on" or vice versa by switch SW1. Pin d is used to control an operation for amplifying outputs from the photodiodes PD1 and PD2 responsive to variable resistor VR and is also used as a terminal for controlling the gain of an amplifier in combination therewith. In addition, pin e is the earth terminal and pin f is a positive power terminal.
FIG. 3 is a block diagram showing the overall construction of an integrated circuit. As described above, the respective pins a to f are arranged so that they each have two or more functions in order to reduce the number of pins needed. In addition, small-storage capacitors are arranged in an integrated manner. In the drawings, a light-responsive circuit 11 operates to amplify the sum of the photoelectric current produced by photodiodes PD1 and PD2 or the difference between those photoelectric currents, and the thus-amplified signals are inputted to an amplifier 12. Such signals are compared with reference voltages by using three comparators composed of CMP1, CMP2 and CMP3, set in the order CMP1<CMP2<CMP3. Where the CMP1 indicates a low level or the CMP3 indicates in a high level, the compared signal is inputted to a stable indicator circuit 13 for illuminating the LED2 of FIG. 2. In addition, the CMP2 operates to determine whether or not a detection signal is within a predetermined operating range. When the voltage signals exceed the CMP2 voltage, LED3 of FIG. 2 is illuminated via a detection circuit 14 and an output circuit 15. When electric circuit is used as the reflection type, a synchronizing signal is inputted from an oscillator 16 to the detection circuit 14 via a digital PLL (called "Phase Lock Loop") circuit 17 and an oscillation output is taken out of pin b, thereby illuminating LED1 of FIG. 2. However, since it is unnecessary to provide for synchronization through an oscillation output in the case of the transmission type operation, a synchronous/non-synchronous selector 18 stops the oscillation output supply. Further, an operation control circuit 19 is caused to respond to the change in voltage due to the on-off operation of switch SW1 so as to reverse the operation of the LED3, thereby suitably selecting either of the "dark on" or the "light on" states. Furthermore, a self-diagnosing output is taken out via output circuit 15 from a self-diagnosing circuit 20 for detecting whether the internal circuit is in a disconnected state. In addition, an overvoltage caused by the short-circuit of the external output transistor Q2 is fed back to cut off outputs to be received. Designated at numeral 21 is a mode control circuit operative in response to the change in resistance of the external variable resistor VR for performing the change-over of the amplification of the sum and difference between the photoelectric current, to be carried out within the light-receiving circuit 11, the adjustment in the balance of sensitivity of the photodiodes PD1, PD2 and the gain control of the amplifier 12. Numeral 22 indicates a parallel constant-voltage circuit for supplying power to the entirety of the IC. As shown, a block 54 surrounded by a dotted line corresponds to an IIL (called "Integrated Injection Logic") circuit.
FIG. 4 is detection output circuit for functionally providing a detection output at pin a. Conductor 31 receives a detection signal obtained by subjecting a received photo-signal to a detection circuit and conductor 32 receives a self-diagnosing signal to be outputted when trouble, such as a disconnection, takes place in the internal circuit. Conductor 33 provides a short-circuit control signal inputted to the detection circuit if an output transistor is short-circuited, conductor 34 provides a detection output and conductor 35 provides a self-diagnosing output. When detection signal at conductor 31 is fed from the detection circuit prior to the electric circuit referred to above, transistors q1 and q2 are turned on so that current limited by a resistor R6 flows. As a consequence, LED3 is illuminated and base current flows through an output transistor Q2, thereby turning on transistor Q2 and producing a detection output at conductor 34, whereby the function of the output circuit is effected. Accordingly, the present electric circuit is designed to perform the generation of a detection output at 34 together with the illuminating function of LED3 by the single pin a. Here, the transistor q2 and the resistor r6 operate to function as a first gate.
A description of the short circuit protecting function will be provided next. Where the output transistor Q2 is unintentionally shorted to the positive power supply overcurrent flows therethrough, so that voltage across a resistor R5 is increased rapidly. As a consequence, voltage applied to pin a also increases and causes an increase in the emitter voltage of a transistor q4 which has already been cut off. Transistor q4 is then turned on to deliver shortcircuit protection signal at 33 indicative of the occurrence of a short to the internal circuit so as to break off the supply of detection signal at 31. When information on the short circuited state of output transistor Q2 is inputted to the internal circuit via pin a, the supply of the detection signal to transistor q2 is cut off, thereby making it possible to avoid breakdown of the transistor Q2 through a continuous overload.
The self-diagnosing output signals at conductor 35 will further be described. Assume that the self-diagnosing signal 32 is generated due to a failure such as the disconnection of the internal elements, and by way of example also assume that no detection signal at 31 is supplied to the electric circuit. In this case, a transistor q3 is turned on, followed by the turning on of a PNP transistor Q3 and transistor Q4, whereby the self-diagnosing output is externally taken out. Resistors R4 and R7 form a resistive potential divider, i.e., a voltage divider used for controlling voltage in such a way that the emitter voltage of transistor Q3 becomes smaller than the voltage corresponding to VBC +VL of the transistors Q3 and Q2. In other words, the resistive potential divider is arranged in such a way as not to cause current to continuously flow along the path formed by Q3, LED3 and Q2. Transistor q3 and resistor r5 function as a second gate. A constant-current circuit may be employed in both the first and second gates, said gates composed of the combination of transistor q2 with resistor r6 and the combination of transistor q3 with resistor r5 respectively. In this case, when the first gate reaches a high current level, the detection output at 34 is provided, while priority is given to the circuit for producing the self-diagnosing output at 35 when the second gate reaches a high current level. To summarize, both gates are used as switching elements and if either one of the first and second gates is turned on both gates may function as the detection circuit and the self-diagnosing circuit respectively. As a consequence, detection output at 34 and self-diagnosing output at 35 can be provided on a shared basis via the single pin a.
FIG. 5 shows a synchronous control circuit which provides a principal synchronizing function given to pin b. When a train of pulses shown at conductor 41 is generated by the pulse generator circuit, the pulses pass through transistors q11 and q12, and the pulse voltage is applied to a transistor Q1 by way of pin b. As a result of current amplification, a projection-type LED1 is flashed at a time interval corresponding to the pulse repetitive interval. In addition, the base current to a transistor q13, whose base is connected in common to the base of transistor Q1, is developed via a resistor r12. As a result, transistor q13 is always kept in an on-state, so that transistor q14 is also held in a on-state. Accordingly, a synchronizing/nonsynchronizing switching signal is produced at conductor 42 when an on-state is inputted to a detection circuit and a PLL circuit subsequent to the oscillator, and is then outputted so that the flash timing of LED1 is synchronized with the light-receiving timing thereof. Malfunctions caused by other factors, such as noises, can be controlled.
A projecting means is indispensable for a reflection type photoelectric switch. However, since a separated projector is employed in a transmission type photoelectric switch, it is necessary to drive the circuit according to the present invention as an IC only as a light-receiving circuit. In other words, it is unnecessary to illuminate LED1 if the photoelectric switch is employed only as a light-receiving element. Further, since it is difficult in typical installations to provide a synchronizing line, i.e., conductor, between a separated projector and the light-receiving unit, a non-synchronous operation may normally be employed when a transmission type photoelectric switch is used. For that purpose, the base of the transistor Q1 is directly connected to a power pin f using a conductor A, illustrated by a dotted line in the circuit, according to the present invention. This provides the short-circuit between the base and emitter of the transistor q13. As a consequence, transistor q13 is turned off and at the same time, transistor q14 is also turned off, whereby the synchronizing/nonsynchronizing switching signal at 42 reaches a low level and hence the detection circuit and the PLL circuit, both provided subsequent to the present oscillator, are changed over to a non-synchronous function. Conductor A is provided on a preliminary basis in manufacture of the circuit of the present invention. The circuit may be used as a reflection type where no conductor A is used, while it may be used as a transmission type if conductor A is used. In addition, the repetitive changeover of the reflection and transmission types is normally not carried out after a switch is installed. Where the photoelectric switch is used as transmission type, it is only necessary to short pins b and f by soldering in the final production step. As an alternative, a switch may be provided midway on conductor A so that the change-over of the pins is performed easily when in use.
FIG. 6 shows a stable indication circuit for functionally making use of a stable output provided to pin c. Here, a description will address the control of stable indication LED2. At conductor 51 stable indication signal is provided when voltage corresponding to a detection signal is compared with the reference voltage by the comparator prior to said electric circuit and the level of the signal obtained by the comparison is within a stable level. Conductor 52 provides a signal for performing the change-over of the function of operation indicating LED3, i.e., an operation switching signal for performing the change-over of operation modes of "dark on" and "light on". Designated at numeral 53 is a constant-current circuit, while numeral 54 indicates an IIL circuit which functions in response to a clock pulse from an oscillator incorporated therein.
When the stable indication signal at 51 is inputted to the electric circuit from a preceding circuit (assume that the signal at 51 is taken as a low-level signal when in the stable state, while it is taken as a high-level signal when in the unstable state), a transistor q22 acting as a switching means is turned off by the low-level signal. Therefore, another transistor q23 also acting as a switching means and arranged in a reversed relation with transistor q22, is turned on so that current IL flows through LED2, resulting in the illumination of the LED2. At the same time, current IL flows as injection current for IIL circuit 54 through the transistor q23 and a resistor r25. Since IIL circuit 54 is a current-drive type logic circuit, circuit 54 can be manufactured, during a process of growing a bipolar IC, by the same diffusion process as in a linear circuit including, for example, a photodiode as a light-receiving element, an amplifier, etc. Therefore, an IC in which the linear and logic circuits have been mixed together can be constructed in a relatively simple manner. Meanwhile, since the required amount of injection current is on the order of 10 μA per gate, the number of the gates becomes greater, thereby resulting in a complex circuit. Thus, the circuit will consume more current. For the IIL circuit necessary for the above circuit, an injection current of about 3 mA is needed. The voltage to be required for consumption is however 0.7 V alone. Accordingly, it will be a waste of current if current is singly supplied from the power supply. By paying attention to the relation between the current and voltage values, the inventors have made use of the feedback current which flows through LED2. In other words, LED2 is turned on so that the current IL flows through transistor q23 and resistor r25. However, it is necessary to supply the injection current to IIL circuit 54 eve when LED2 is in an offstate. In this case, transistor q22 and resistor r24 are used as a bypass, i.e., a shunt path. When the signal at 51 becomes a high level and hence LED2 is turned off, injection current is supplied to IIL circuit 54 via transistor q22. Accordingly, the emitter of transistor q22 is connected to that of transistor q23 so that the injection current is supplied through both lines of the emitters thereof to the IIL circuit. The injection current can selectively be supplied by the switching action of both transistors, thereby making it possible to significantly reduce current to be consumed in the entirety of the photoelectric switch.
The operation control switching action in FIG. 6 is performed in the following manner. A switch SW1, connected in parallel with a diode D1, is joined to LED2, and a comparator CMP4 detects the change in the difference in voltage between on and off states of the switch SW, whereby the switching operation is performed. The preset voltages corresponding to the voltage drops caused by the switching of SW is determined based on the characteristics of voltage vs. current between LED2 and diode D1 as shown in FIG. 7. In other words, in order to detect, in a circuit subsequent to the electric circuit of FIG. 6, whether or not a voltage drop across diode D1 exists, it is necessary to continuously maintain a slight flow of current (corresponding to level low enough that the LED2 does not illuminate so as to develop a voltage drop), namely, this corresponds to the fact that constant-current circuit 53 provides a constant current ID corresponding to the slight current at this time. On the other hand, assume that current required to illuminate LED2 is IL. A positive input voltage supplied to comparator CMP4 varies depending upon the on-off state of switch SW, i.e., the absence or presence of the diode D1 as illustrated in FIG. 7. Since diode D1 is in a short-circuited state upon turning-on of switch SW, only LED2 develops a voltage drop. However, when LED2 is illuminated and hence current IL flows in the circuit, the maximum voltage drop develops. This maximum voltage is represented by -VL. In contrast, when switch SW is turned off, LED2 is connected in series to diode D1. At this time, the minimum voltage drop is obtained when the current is ID, said current being produced upon turning-out of the light of LED2. At this time, the minimum voltage is represented by -Vd. In this case, if the reference voltage -Vs of the comparator CMP4 is established as an intermediate voltage between the voltages -VL and-Vd, indicated at dotted lines in FIG. 7, it is possible to determine, as a high or low output by the comparator CMP4, whether a voltage drop across diode D1 exists. Such an output permits a changeover of the output mode of the operation indicator. In the circuit according to the present invention, when switch SW is turned off, the output transistor is turned on ("light on") in the presence of incident light, while when the switch SW is turned on, the output transistor is turned off ("dark on") upon incidence of light. However, the present invention should by no means be limited to this and this function may be set freely in a reverse relation.
FIG. 8 is a multifunction detection circuit for effecting a principal function of pin d. Photodiodes PD1 and PD2 are separated and connected to a differential amplifier composed of a pair of transistors q33 and q34. Assume that voltage across an external variable resistor VR is 0 volt, i.e., when the neutral point, namely, the movable contact of the variable resistor VR is in a GND position. In this case, transistors q31, q36, q32 and q43 and diodes d1 and d2 are all in a cut-off state. Their effect is negligible in the circuit. On the other hand, current mirrors composed of transistors q35 and q41 will cause current flow in transistor 35, said current of transistor q35 having the same magnitude as that of the current of transistor 41. Assume that the condition between resistors r36 and r38 is set as r36>r38. In this case, the supply of predetermined constant current to the transistor q35 become infeasible, so that the transistor q35 reaches a saturated state, resulting in the same as the on-state. As a result, the impedance of the transistor q35 becomes substantially zero. Accordingly, photoelectric current produced by photodiodes PD1 and PD2 is equally amplified by the transistors q33 and q34. Thereafter, the collector current thereof is obtained collectively at the resistor r36 through diodes d3 and d4. As a result, this circuit functions as a cumulative amplifier circuit, which is operative for amplifying both of the collected outputs so as to perform addition of both outputs.
On the other hand, when a voltage applied to pin d is raised to the power-supply voltage by adjusting the resistance of the variable resistor VR, the emitter voltage of transistor q31 and the collector voltage of transistor q33 are increased and current is then supplied to the current mirror composed of transistor q35 through transistor q33, whereby transistors q33 and q34 operate to function as the differential amplifier. In other words, since the base of transistor q33 is on the side of the positive input and the base of transistor q34 is on the side of the negative input, the base of transistor q33 is kept 2VF (forward voltage of the diode), i.e., 2 times the fixed voltage V�F. This 2VF becomes a bias point of the differential amplifier circuit. As a consequence, it is possible to realize a circuit which is operative for adding two outputs from photodiodes PD1 and PD2 until the potential at pin d reaches 2VF and for performing subtraction of the outputs when in the excess of 2VF.
Further, both photodiodes, PD1 and PD2, are normally kept in the same operation state upon performance of their differential amplification. However, in practical use, it is necessary to make it possible to reduce the sensitivity o photodiode PD1 relative to photodiode PD2 and to keep detectable regions variable. In order to perform the adjustment in the balance of sensitivity between photodiodes PD1 and PD2, a transistor q42, a transistor q43 and a diode d2 are used. In this case, when the voltage applied to pin d is gradually increased, a voltage applied to the emitter of transistor q42 is also increased, while current flowing through transistor q42 also becomes progressively greater. This current flows through diode d2 but a tangential resistance ΔR of the diode d2 decreases with an increase in current. As a consequence, when the value of the current becomes greater as above, the photoelectric current produced by photodiode PD1 connected in parallel with diode d2 is reduced as the tangential resistance decreases and hence its output becomes smaller. The changes in tangential resistance values of diode d2 is illustrated in FIG. 9. Here, the characteristic of current vs. voltage of diode d2 is plotted as a curve, while straight lines are indicative of the tangential resistances relative to the current values. As described above, as the voltage applied to pin d approaches the power-supply voltage, through the use of external variable resistor VR, the sensitivity of photodiode PD1 can be lowered. It is therefore possible to control the balance of sensitivity between photodiodes PD1 and PD2 and to perform a so-called two-dimensional detection, taking the regions to be detected as faces.
Furthermore, pin d can provide another function, that is, the voltage gain of an a.c. amplifier provided subsequent to a light-receiving circuit can be controlled in accordance with the changes in resistances of the variable resistor VR. The potential at the emitter of transistor q39, which serves as a constant-current source for the a.c. amplifier, is applied to pin d through a resistor r39. Therefore, when the voltage across pin d is zero volt, i.e., when at the neutral point, namely, the movable contact of variable resistor VR is on the side of GND, the maximum current will flows through transistor q39 used for the constant-current source. When its voltage reaches about 150 mV, no current flow through transistor q39. In addition, since the amplification factor of the differential amplifier circuit in the a.c. amplifier is proportional to that of transistor q39 which is used for the constant-current source, the gain of the a.c. amplifier can be changed by the external variable resistor VR. It is therefore possible to vary its gain based on d.c. voltages applied to pin d in this circuit. As a consequence, it is also feasible to control the gain in accordance with control voltages from other circuits and to provide a remote control by d.c. voltages applied from a distance.
Next, FIG. 10 shows a multi-function detection circuit according to a second embodiment of this invention. As an alternative to the use of outputs which consist of composite voltages in the first embodiment, outputs composed of composite currents are employed in the present embodiment. Thus, in the first embodiment, in spite of the fact that transistors were used for performing the current amplification, the received inputs are taken as the values of voltages, even in the case of both the cumulative and differential amplifications, and such voltages are collectively applied across resistor r36 to make composite voltages. As a result, impedance variations cannot be neglected in the circuit. The formula for the frequency characteristic is given by:
F=1/(2πR.sub.L C.sub.0)
However, in this case, the frequency characteristic must depend upon impedance RL. Limitations are therefore imposed on an improvement in the frequency response. As a consequence, the procedure of adjusting the light-receiving timing of the photoelectric switch itself must be changed and hence the malfunction may occur due to other photoelectric switches and external factors. Since the received photo-signal is dependent upon impedance RL, it is possible that the photodiodes reach a saturated state due to light disturbance. In the above formula, symbol C0 is the capacitance of each photodiode. The second embodiment shown in FIG. 10 provides a light-receiving circuit having a higher reliability. In the drawing, conductors and photodiodes to be used are similar to those in the first embodiment. However, three current mirrors are composed of transistors q51, q52, transistors q54, q55 and transistors q56, q57, respectively. Photoelectric current produced by the photodiodes PD1 and PD2 is made composite and the composite current is then delivered to an a.c. amplifier 61 so as to output the amplified current as a detection signal through an output line 62. The current mirror composed of transistors q54, q55 and another current mirror composed of transistors q56, q57 will hereinafter be referred to as first and second current mirrors respectively.
The operation of the above circuit will now be described, taking each potential at a variable resistor VR as a reference voltage level. First of all, when the potential at the neutral point, i.e., the movable contact of variable resistor VR is 0V, namely, when the point thereof is connected to a GND side, no current flows through the bases of transistors q51, q52, the emitter of transistor q56 and the base of transistor q58 because their potentials are zero volts, and hence transistor q57 also reaches a cutoff state. Accordingly, the current (I1 +I2) obtained by summing up the photo-current produced by photodiodes PD1 and PD2 flows through an electrical path between the emitter and the base of transistor q54. In the first current mirror, the value of the collector current, as a secondary output, of transistor q55 is identical to that of the base current, as a primary output, of transistor q54, namely, it is equal to the current (I1 +I2). As a consequence, a potential develops across a resistor through the output line 62 via the a.c. amplifier 61, whereby the first current mirror functions as a cumulative amplifier circuit. Thereafter, when the potential at the neutral point, i.e., the movable contact of the variable resistor VR is gradually increased, current begins to flow through transistors q56, q57 which constitute the second current mirror and transistor q58. However, the base current of transistor q54, whose current corresponds to the primary output for the first current mirror, is reduced by the amount corresponding to the current which flows through transistors q56, q57 and transistors q58. Thus, the voltage applied to the resistor r54 is gradually reduced, and when the photoelectric current produced by photodiodes PD1 and PD2 is matched in level with the amplified current from transistors q56 and q58, whose current is taken as the primary output for the second current mirror, the sum of the outputs becomes zero.
With an increase in the potential at the neutral point, i.e., the movable contact thereof is adjusted away from ground, its potential overcomes the voltage drops between the base and the emitter of transistor q51 and between the base and the emitter of transistor q52, said voltage drops limiting the flow of the base current of transistors q51 and q52 which constitute a current mirror, so that the base current begins to flow therethrough and hence collector current flows through the collector of transistor q53. Current corresponding to the collector current is supplied to the base of transistor q54 as bias current which is taken as the primary output for the first current mirror. On the other hand, the supply of current from the emitter of transistor q58 applies the reverse bias to transistor q59, which functions as a diode, so that the flow of current of transistor q59 is cut off. As a consequence, the current which flows through the base of transistor q54 does not depend upon the photoelectric current produced by photodiode PD2 and thus, exclusively depends on photoelectric current I1 produced by photodiode PD1.
When a further increase in the potential at the movable point of variable resistor VR occurs, more current will start to flow through transistor q58. However, the flow of the current is limited by photodiode PD2 which is connected to the emitter of transistor q58. Accordingly, the collector current of transistor q56, which is the primary output for the second current mirror, is also limited, resulting in the limitation of the base current of transistor q54 whose current is the primary output for the first current mirror. In other words, the current which flows through the base of transistor q54 is given by a difference current (I1 -I2), so that this circuit functions as a differential amplifier circuit. Incidentally, a voltage used to set the biasing point between the cumulative and the differential amplifiers become about VDD /2 which is equal to the potential at the neutral point of the variable resistor VR. FIG. 11 is a graph for describing the relationship between individual potentials at the neutral point, i.e., the movable contact of the variable resistor VR and respective received photo-outputs. An inclination A represents a result of the cumulative amplification, while an inclination B represents a result of the differential amplification. Here, the region surrounded with two corrugated lines, which are defined adjacent the potential VDD,/2, is not employed when in practical use because of poor reliability.
Further, gain control in the second embodiment can be carried out in the same manner of operation as in the first embodiment.
FIG. 12 is a graph obtained by comparing the frequency characteristics of the light-receiving circuit, according to the first embodiment, as shown in FIG. 8, with those of the light-receiving circuit according to the second embodiment, as shown in FIG. 10. This graph indicates that if seventy percent of the relative outputs are taken as a region for practical use, the first embodiment can provide frequency response up to 50 Khz, while the second embodiment permits frequency response up to about 5 Mhz, one hundred times that of the first embodiment.
FIG. 13 is a circuit diagram showing the principle behind the light-receiving circuit employed in the second embodiment and which is for briefly describing the function for making current composite. Symbols Q61 and Q62 are PNP transistors which constitute a current mirror in which a base terminal is common to them. An incoming photo-signal is taken as the change in the value of current. In this circuit construction, no current flows through the bases of transistors Q61 and Q62 in the absence of light incident on the photodiode, so that the current mirror remains at a cutoff state and hence no output is taken out through the current mirror. On the other hand, as current flows responsive to the presence of light incident upon the photodiode, the current flows through the bases of transistors Q61 and Q62 in the same amount. Therefore, the current which flows through the collectors of the two transistors is the same, whereby an output to be produced by this circuit may be taken as the change in the value of current corresponding to photoelectric current from the photodiode. In addition, the frequency characteristic in the circuit is represented by:
F=1/(2πR.sub.D C.sub.0)
In this case, it is apparent that no frequency characteristic depends upon the impedance RL. Here, RB is a bias resistor, RD is a tangential resistance of each of the transistors Q61 and Q62. However, this tangential resistance is slight in value. It is therefore apparent that frequency response in the circuit can be significantly improved. Symbol C0 is the capacitance of the photodiode. A detection output is obtained by making a potential across a resistor RL, using collector current which flows through the transistor Q62. Finally, said output falls under the control of resistor RL. However, it is necessary for RL to produce the required potential to satisfy the output requirements so that it does not have an adverse effect upon the frequency characteristic.
As described in the second embodiment, and in view of the inherent function of the transistor, i.e., current amplification, current corresponding to the photoelectric current produced by the photodiode has been taken out to improve the frequency response in the circuit. As a result, it is possible to protect the photodiode from electrostatic noises by additionally forming a shielding layer and to also adopt the construction for making a positive use of even the photoelectric current produced by the shielding layer. A laminated structure for the photodiode employed in the second embodiment is illustrated in FIG. 14. The drawing is a cross-section showing a part of the photodiode which has been made on an IC, said IC being formed by the epitaxial ("ep") growth, including the overall light-receiving circuit. In other words, an N ep layer is grown on a P sublayer and a P sp layer is grown on the N ep layer. The cathode and the anode are led out of the ep layer and the sp layer respectively. The anode is grounded together with the sub layer. Since such a construction can provide a function in which the surface of the P layer serves as a shield, external electrostatic noises or the like do not affect this construction. Where such a construction is not employed, photoelectric current flows only through the ep-sub layers. However, in the FIG. 14 embodiment the photoelectric current can flow even through the sp-ep layers because the P layer has been grown on the ep layer. The relationship in wavelength between the ep-sub layers and the sp-ep layers is determined depending upon the difference in thickness between the ep-sub layers and the sp-ep layers. In other words, this photodiode is operated in such a way that light with a long wavelength is incident upon the ep-sub layers, while light with a short wavelength is incident upon the sp-ep layers. However, the capacitance in the sp-ep layers is considerably increased compared with that in the ep-sub layers. Accordingly, as described in the first embodiment, although the above-described circuit construction, in which voltage is taken as a detection factor, can avoid the influence of noises by means of a shield, the photoelectric current which flows through the sp-ep layers is not available, making it possible to take the frequency response of the entire circuit into consideration. On the other hand, the detection signal output has been taken out, with current being taken as the detection factor in the circuit according to the second embodiment. It is therefore possible to neglect the impedance in the circuit, so that the circuit according to the second embodiment may use even the photoelectric current which flows through the sp-ep layers. Accordingly, the entire outputs produced by the photodiodes are obtained as a result of addition of photoelectric current which flows through the sp-ep layers to that through the ep-sub layers. It is therefore possible to spread out the regional wavelength of the frequencies corresponding to the summed values of the photoelectric current as compared with the first embodiment and hence to increase the outputs from the photodiodes. FIG. 15 is a schematic view showing the FIG. 14 photodiodes as a circuit diagram, as employed in the second embodiment, and FIG. 16 is a graph illustrating photoelectric current produced by the photodiodes.
In the circuit according to the present invention, a number of functions described above have collectively been provided in a single IC chip. In addition, it is only necessary to separate the internal circuit from the externally-mounted circuit by way of the six pins a to f. Multi-functions are given to the individual pins exclusive of a pair of power pins, whereby the number of pins may significantly be reduced. In addition, a novel electric circuit is employed for each function, so that a device, as a photo IC, having extremely-high sensitivity and reliability can be provided.
|Cited Patent
|Filing date
|Publication date
|Sep 23, 1987
|Feb 28, 1989
|At&T And Philips Telecommunications B.V.
|Preamplifier for an optical receiver
|Citing Patent
|Filing date
|Publication date
|Oct 30, 1996
|Jul 28, 1998
|Samsung Electronics, Co., Ltd.
|Pulse-shaping circuit
|Jun 10, 1997
|Aug 10, 1999
|Denso Corporation
|Photoelectric sensor circuit comprising an auxiliary photodiode and a current mirror circuit
|Dec 30, 1997
|May 27, 2003
|Gelcore Llc
|LED lamp with a fault-indicating impedance-changing circuit
|U.S. Classification
|International Classification
|Cooperative Classification
|European Classification
|Oct 1, 1990
Owner name: ASTEX CO., LTD., JAPAN
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:FUKUYAMA, TOSHIFUMI;REEL/FRAME:005461/0072
Effective date: 19900918
Owner name: TAKENAKA ELECTRONIC INDUSTRIAL CO., LTD., JAPAN
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:FUKUYAMA, TOSHIFUMI;REEL/FRAME:005461/0072
Effective date: 19900918
|Jun 15, 1993
|Certificate of correction
|Sep 21, 1994
|Fee payment
Year of fee payment: 4
|Feb 16, 1999
|Maintenance fee reminder mailed
|Jul 25, 1999
|Lapse for failure to pay maintenance fees
|Oct 5, 1999
|Expired due to failure to pay maintenance fee
Effective date: 19990723


text:
100, 373 Likes 1, 399 Dislikes
►Learn the piano here: http://goo.gl/Uw5CEn
►SHEETS: http://mnot.es/2i71rwE
►iTunes: https://goo.gl/UoQSft
►GooglePlay: https://goo.gl/M8q5EH
►Amazon: https://goo.gl/oMM7ZE
►MIDI: http://goo.gl/PQjV5x
►PATREON: https://www.patreon.com/AtinPiano
►FACEBOOK: http://www.facebook.com/AtinPiano
►TWITTER: https://twitter.com/AtinPiano
This is Cantina Band from the original Star Wars - A New Hope with an improvised intro of Binary Sunset aka The Force Theme.
I've purchased a couple of Star Wars piano sheet books and all the arrangements were really boring and bogged down. After some research I stumbled upon this insane transcription by Keeper1st (https://youtu.be/CdGGHbv5VWU) which is as accurate to the original song as you can get but also incredibly challenging. So I made some adjustments to make it playable without changing the sound too much.
Also, as this song progresses during the bridge, it devolves into something that is neither fun to play nor pleasant to listen to so I decided to jump back to the main theme halfway through the bridge.
Music composed by John Williams
Arranged for piano by AtinPiano
Soundmix by sayasound.com
Star Wars © Copyright: 1977 20th Century Fox

subset: commoncrawl


text:
2040 Long Range Transportation Plan Final Report
Evacuation Zone Lookup
Evacuation Routes
Evacuation Zones & Routes Map (PDF)
Disaster Guide
Pet Friendly Hotels
Shelter Information
Pet Friendly Shelter Information
Special Needs Shelter Information
Printable Family Contact Cards
Fuel on GasBuddy.com
Gulf Power Outage Map
EREC Outage Map
National Hurricane Center
National Weather Service Mobile
Local Media Outlets
Residents can request non-emergency services for road issues, Pensacola Beach resident services, stormwater maintenance and much more through Ask MyEscambia, a mobile and web application. Ask MyEscambia can be accessed on a desktop computer at MyEscambia.com/ask, or residents can download the mobile app for free by searching "Ask MyEscambia" in the Apple App Store and Google Play Store or searching.
"PublicStuff" in the Windows Store or BlackBerry App World.
Updated Noon 10/8/17
Join our mailing list for the latest news during an emergency event.


text:
Supreme talents at work hinder plans to recruit
As a man whose glass is generally half-full, even when containing champagne to toast winning the Community Shield, it would be no surprise if Roberto Mancini dwelt on the one potential downside of his side's impressive victory over Chelsea at Villa Park yesterday.
Much of Manchester City's football was so breathtaking, their attacking players brimming with ingenuity and invention, that it is difficult to see the club's owners acquiescing to his demands for even more firepower.
The imminent arrival of Jack Rodwell from Everton, for a £15 million fee, was announced an hour before kick-off, but there are unlikely to be many more arrivals, and it is not clear precisely where the England midfielder will fit in either.
Mancini's assessment afterwards that the player "needs…


text:
Judge Revives Oil Leases On Alaska's North Slope
On Monday, Alaska Superior Court Judge Sharon Gleason struck down the DNR's decision to cancel the leases, in part because the appellants — ExxonMobil, ConocoPhillips Alaska Inc., Chevron USA Inc. and BP Exploration (Alaska) Inc. — were...
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text: Day 70 21 October 2012 Posted by Tim 2005: Vesna spends much of the day feeling anxious about her weight, and thinking she's going to gain a lot because of all the bread and pasta the housemates eat. Tim tries to talk her into exercising, but it doesn't go anywhere, and Vesna's constant talking on the subject infuriates Dean. Share on Tumblr


text:
Putting the wrong date on an invitation is usually a bad thing.
Last week I told how our home group was planning to meet in a local park, next to a low-income apartment complex. We decided to have a free BBQ, but we didn't want to do a "bait-and-switch," so on the flyers we delivered to every apartment we told them we're inviting them to hang out with us and talk about Jesus. They knew up front what we were doing. We planned it for Sunday morning from 11-1.
The flyers went out on Thursday, June 7. We talked, planned, and most of all prayed. We got burgers, watermelon, chips, and cookies together and got together early to prepare and wait for people to come.
We waited.
Finally we talked to one guy. We told him we put out flyers. "Oh, the ones that say 'June 6' with no day of the week on them?"
Yes, that would be us.
I'm certain the computer automatically put the date of when it was done. So we now had 50+ apartments, 100 burgers, and 0 people.
We decided we'd better go knocking.
We went around to each complex again, inviting people to come. My wife and I knocked on the door of one woman who was fairly sick and couldn't come out into the windy cold weather. We said we'd bring her a plate of food. My wife nominated me since I'm medical and the woman was visibly ill. I brought her a plate and got visiting with her. It turns out I had something left over from my mom that was used twice and would be a good help to this new friend. She was very excited to get something that would help her in her illness, and I was excited to give her this device after holding onto it for several years.
I came back to the park and we had several people come and go. I think we ended up with around 20 adults stopping by, with many kids as well. The cool thing about this is it was a good number for us to start with. Between our group of 9 adults, we got to talk to everyone who came for at least a few minutes. I got to meet a couple of guys who were happy to hang out. They liked that people gathered at this park to spend time with them. I talked with them, learned about some of their troubles and their lives. I never had to force it, but I was able to share about Jesus with them.
Everyone in our group had similar stories. It was an amazing time. We wrapped up and I think we all were thinking, "Why hadn't we done this before?" It was so simple. We served people. We treated them with respect and listened to them. One of our group had prepared a talk, but it didn't work out.
We hadn't even decided what we were going to do next week, but we had such a good time we realized we should go back again and build some relationship. We might move to other parks during the summer, but for this week we'll take the next step. Even though the wrong date could have torpedoed our plans and our resolve, God was good to give us what we could handle.
If you have questions about what we are doing or how things went, I'd be happy to discuss it. We'll see what the future holds.


text:
Jeff Brown, DVM
Click on the Doctor's name to see their biography and picture:
Dr. CaldwellDr. Stephens Dr. Landreth Dr. Suzanne LiDr. BettenhausenDr. BrownDr. Johnson Dr. Jeff Brown, a native of Ohio, graduated summa cum laude with a Bachelor's Degree in Animal Science from The Ohio State University before continuing on to earn his doctorate at The Ohio State University College of Veterinary Medicine in 1979. Although a true Buckeye at heart, he relocated to Arizona that same year where he has practiced ever since.As a past President of the AZVMA, Dr. Brown has held every office position within that association, including the AZ State Delegate to the national AVMA House of Delegates. For nearly a decade he served on the AZ State Veterinary Medical Examining Board's Investigative Committee. In 2013 Dr. Brown received the Arizona Veterinary Medical Association's Distinguished Service Award. He is also the proud parent of two daughters, Carly and Jaime. The girls, along with his partner, Jeanne, are passionately interested in art. In his spare time, he enjoys many activities such as hiking, boating, fishing, trap shooting and sculpture welding. The four-legged members of the family, all rescues, have dwindled down to just 4 cats.


text:
What is Beryllium?
Beryllium is a rare metal mined from the earth in the United States, China and Khazakhstan exclusively. Ultimately it is reduced to powder form for use in processes where a metal having any one of the unique properties of beryllium is necessary. It is stronger than steel but much lighter. It is also extremely resistant to high heat and corrosion and it is extremely rigid while flexible. These extraordinary characteristics are essential to understanding its extremely toxic nature once it is inside the human body.
The special characteristics of beryllium have led to a demand for it in aerospace, weapon, satellite and ceramic industries. Because it is extremely heat resistant it is used in heat transport and heat sinking applications. Because it is transparent to X-rays and other forms of ionizing radiation, it is commonly used as window material in X-ray equipment and particle physics experiments. Today beryllium use is strictly controlled because of its unusual toxicity to humans.
How Can Beryllium Harm You?
Beryllium exposure can cause the lung disease berylliosis, known today as Chronic Beryllium Disease (CBD). Unlike most other toxic exposures, extremely low or intermittent exposures to beryllium are recognized to cause CBD. As hinted above, beryllium's toxic potential is extraordinary because even a single exposure to beryllium can be sufficient to cause CBD and death ten years after the exposure event.
CBD initially resembles tuberculosis or sarcoidosis in that victims cough and are out of breath. Eventually the person may experience chest pain, joint aches, weight loss, and fever as the body attempts to activate enzymes to neturalize the beryllium in the body. Unfortunately, CBD is incurable but the symptoms can be treated.
The modern era's awareness of beryllium's toxicity is gained through the story of workers and the families of workers of Brush Wellman's Lorain, OH beryllium manufacturing plant. Wives who never set foot on the plant floor suffered from CBD after washing their husband's dirty clothes. Secretaries who never came into contact with the manufacturing process developed CBD through casual contact with workers. The current occupational limit of 2 micrograms per cubic meter was adopted without clear data that it would protect human beings. It is still possible to develop CBD due to exposure beneath this standard.
If you or a loved one suffers from a Chronic Beryllium Disease (CBD), please contact the Madeksho Law Firm, PLLC for a free consultation with an attorney.
How Can We Help?
For over 40 years, attorneys at the Madeksho Law Firm, PLLC have won compensation for our clients against the largest chemical companies in the world. In a world where cancer and sickness are becoming more common, the only way to prevent unnecessary risk is by holding companies accountable for negligently exposing us to cancer-causing products. If you choose the Madeksho Law Firm, PLLC for legal counsel, we will do our duty to keep you informed and protected in a professional, compassionate manner.


text:
SPUR forum on "The Future of Regional Planning in the Bay Area" (San Francisco; 3/31)
Expand Messages
- The Future of Regional Planning in the Bay Area
Thursday March 31st
12:30 pm to 1:30 pm
Many of the most pressing planning questions of our day occur at the
regional level: How do we address sea-level rise? How should we alter
our land-use patterns to combat climate change? Join leaders of the
Bay Area's four regional agencies to discuss planning for our region's
collective future. With Steve Heminger of the Metropolitan
Transportation Commission, Ezra Rapport of the Association of Bay Area
Governments, Will Travis of the Bay Conservation and Development
Commission and Jack Broadbent of the Bay Area Air Quality Management
District. Moderated by SPUR executive director Gabriel Metcalf. Given
all the work on SB 375, this will be a unique opportunity to hear from
the four executive directors together about how to further join their
agencies towards a common agenda for the Bay Area.
All forums are open to the public; Free for SPUR members and $5 for
the general public.
Location: SPUR Urban Center, 654 Mission St. (between New Montgomery & Third).
Thank you and we look forward to seeing you at SPUR.
Your message has been successfully submitted and would be delivered to recipients shortly.


text:
Over two thirds of Facebook's users (and over half of YouTube's) now visiting via mobile devices
The majority of visitors to Facebook and YouTube already use a mobile phone or tablet (or both), and Ebay is not far behind, the latest cross-device audience data from Roy Morgan Research shows.
Almost 13 million Australians visited Facebook in an average four weeks in the 12 months to March 2015, up 10% from 11,759,000 in the year to March 2013.
8,765,000 of those visitors (68%) use a mobile device—a phone, a tablet, or both—for some or all of their visitation, up from 5,303,000 (45% of total visitors) two years ago.
7,595,000 people now use a mobile phone to access Facebook during an average four-week period (up 59% from 4,787,000 in early 2013) and 3,818,000 use a tablet (more than double the 1,876,000 visitors via tablet two years ago). Of these mobile visitors, 2,648,000 go to Facebook via both types of device during the month, up from 1,360,000.
Computers are still in the most common way to access Facebook overall, but far fewer Australians now go online using only these 'non-mobile' means: 4,162,000 Australians use only a computer to visit Facebook in an average four weeks, down from 6,456,000 in 2013.
The way we visit YouTube is also changing—no doubt helped along by the increasing mobile data allowances available for streaming video on the go (but also the rising trend of multi-screening on the wi-fi connection at home).
From March 2013 to March 2015, YouTube's net monthly website audience grew 14% to 11,799,000. Most of these video streamers now use one or more mobile devices during the month (53%, up from 36%): 3,423,000 use a phone, 1,318,000 a tablet, and another 1,504,000 use both.
Ebay's total four-week audience is almost unchanged over the last two years, up less than 1% to 7,300,000. As with Facebook and YouTube, visitation via mobile device has increased, from 2,172,000 (30%) to 3,449,000 (47%)—however this means, of course, that the remainder of Ebay visitors (a majority of 53%) still use only non-mobile computers to access the website.
Number of Australians visiting website in average four weeks:
Source: Roy Morgan Single Source, Apr 2012- Mar 2013 n = 51,172 and Apr 2014 – Mar 2015 n = 51,882 Australians 14+
Tim Martin, General Manager – Media, Roy Morgan Research, says:
"It's astounding how quickly the last two years of rapid smartphone and tablet uptake has influenced cross platform, cross device visitation to Australia's biggest websites.
"The changes in cross device visitation that Roy Morgan Research is seeing are consistent with the rapid shift of online display advertising from non-mobile to mobile formats. Advertising campaigns that would previously have been shown on desktop computers are now being adapted for mobile formats.
"Of course, the results revealed here are missing a crucial element for understanding cross-platform visitation in full: how many of these mobile phone or tablet visitors also still visit via computer? Media owners are under significant pressure to correctly measure their mobile and non-mobile audiences accurately. These 'overlaps' are confounding most measurement systems around the world. Only Roy Morgan Single Source now measures the cross-platform audience, the unique audience by device and shared audiences overlapping across devices. Contact us to discuss accessing this exclusive research."
Contact Profile
Roy Morgan Research
Roy Morgan Research is Australia's best known and longest established market research and public opinion survey company. Roy Morgan Single Source is thorough, accurate, and provides comprehensive, directly applicable information about current and future customers. It is unique in that it directs all the questions to each individual from a base survey sample of around 55,000 interviews in Australia and 15,000 interviews in New Zealand annually - the largest Single Source databases in the world. The questions asked relate to lifestyle and attitudes, media consumption habits (including TV, radio, newspapers, magazines, cinema, catalogues, pay TV and the Internet), brand and product usage, purchase intentions, retail visitations, service provider preferences, financial information and recreation and leisure activities. This lead product is supported by a nationally networked, consultancy-orientated market research capability.
Shaun Ellis
W: www.roymorgan.com


text:
Industrial Steel 4: Rail Detail
Chugging Back in Time
The Waimarie chuffing under the Aramoho rail bridge.
Time Span
This is a time bridge… take it if the time tunnel is closed (:
Do Not Forklift
That's two diesel locomotives and hundreds of tons of rolling stock hurtling past me on the rail bridge…cool!
The people of Creatavia need fear no evil befalling them in the night… they are watched over by the baddest creature on the planet.
A new Creatuie painting! She is watching over her peeps at night from the highest battlements… the girl is not afraid of heights… oh, hang on, she's actually not afraid of anything! (:


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I am such a sucker for new craft books! I usually don't even think about whether I will make something from a book when making the purchase…I just consider how pretty the pictures are and how inspired I feel when I flip through it. Some books stay with me for many years, like Gwen Marston's Liberated Quiltmaking or Kaffe Fassett's Glourious Patchwork. I have never actually made a project from their books. I just like piling up a stack of my favorite quilt books on my bedside table for evening reads. And then I like to make long lists of projects that would be cool to do, but I have yet to follow through on a single one of them.
So you can imagine that I am a bit surprised to find myself not only planning projects from a book, but actually committing to them in a very public way. The title that has disrupted my equilibrium to such an extent is a new book just out from Interweave/F+W Media. The title, Sew Fun: 20 projects for the whole family, by Deborah Fisher contains several projects that are just perfect to do with the youngsters in our family.
The lions on the cover are enough to get me to look through my fabric stash for some good lion-making material, and there are patterns for some seriously lovely dolls that I know would be a hit with every little and big girl (I got lots of oooh-ing and awww-ing over them from other quilting friends): – Look how cute they would be with these bright batiks from Island Batik, some ribbon I have had laying around, and faces with my new favorite embroidery thread from Aurifil.
However, the project in Deborah's book that is really messing with my schedule is the community quilt. First, I showed the pictures in the book to my husband, who has never voluntarily done anything crafty with fabric in his life. He immediately wanted us to make one as a family project….
As if that wasn't enough to take on, I felt strangely compelled to show the book to my daughter's daycare teacher as well. And this is how I find myself committed to making not just one project from Sew Fun, but two. In the process I seem to have promised to volunteer in the classroom to help supervise the toddlers while they are creating their project. Obviously all the later sewing of the quilt is my job as well.
So exactly what did Deborah Fisher write to make me this committed to projects in her book?
Sew Fun has a whole chapter dedicated to helping us involve children in sewing projects, and every project has tips and ideas on how children can be involved. Although the projects are pretty, they are simple enough that you can see how a child can actually participate in the creative process but also complex enough that they are interesting for an adult sewist. I bet a LOT of us will fall in love with Deborah's Hazel Doll.
The more I looked at the projects in Deborah's book, the more I wanted to make some of her projects, and to share the experience with the little people in my life.
Deborah inspired me further by answering some questions about the book and about her life and background crafting with children.
How did you get started in sewing and crafting? Did your parents work with you on projects as a child.
I have always been maker and was very fortunate to have an environment to be creative in! When I was growing up, my father built a big round table for projects in our family room. There were shelves filled with fabric in big round ice cream tubs, like in an ice cream parlor, and there was always paper and trims and other supplies to use. My mother's sewing machine was always on the desk. She is the one who taught me to sew. One grandmother taught me to knit and my other grandmother was a painter.
Are there any projects in your book that you feel are particularly well suited for younger children with less patience and precision?
There are many projects that younger children can help with. I think the key is to know the abilities of the child. There are many tips in the Little Hands, Big Smiles: How to Have Fun Sewing with Children section, including how to alter your sewing machine pedal so that even very young children can help press the pedal while you sew. The chapters also have Kid Work tabs with recommendations of what kids might like to help with. Particularly suited for the youngest children to help with are the Reading Time Quilt, Fun Friends from Odds and Ends, Community Quilt, and Instant Drama Chenille Boa. Also, any of the projects, such as the Topsy Turvy Story Quilt, that use children's drawings are great for having young ones involved without having them do the technical sewing.
You encourage us to not use the pre-programmed embroidery stitches on our sewing machine. Do you have a philosophy when it comes to craft supplies and creativity? Is there such a thing as too much?
I don't think there is anything wrong with machine embroidery, (or any supplies really), as long as it is used as a tool and not as a substitute for creativity and personal expression. Many makers, especially beginners, are afraid to experiment with their own ideas so they rely on pre-made components. I suggest minimal tools and basic supplies so that your individuality can shine!
What is your personal favorite project in your book?
My favorite has always been the Hazel Doll. Dolls were one of the first things I made when I started sewing and they have always been a reoccurring theme in my work through my fine art and my sewing. There is magic in creating a friend. I also love making the accessories. The Hazel Doll has a reversible skirt, a reversible top and a one pattern piece jacket that can be embellished with embroidery and trim. You can make shoes, slippers, a boa, and a ladybug cape for her also. There are so many details that you can add, but she can also be made very simple.
When starting to sew with your child, which techniques and skills do you think they need to master first?
Children usually have the more important skills down pat-fearlessness with their own creativity and ability to embrace their own imaginations. We adults need to aspire to that, I think! For techniques, first a basic straight stitch on the sewing machine and then a simple hand sewn running stitch will give them freedom to express their ideas. Manual dexterity varies so much from child to child. It is our job to guide then towards ways of working that will keep frustration levels acceptable while still allowing them to grow.
Do you have a favorite brand of felt that you use in your felt projects? I have a huge stash of quilting fabric. Can I use those for most of the projects?
I love Wollfilz wool felt. If not wool then I like to use recycled felt. You can make most of the projects in Sew Fun with quilting fabric! I am a mixed media maker so I used a variety of materials in the book, but I encourage readers to use what they have or what they have been wanting to experiment with. Some projects, such as the Insect Capes and There's No Place Like Home Pillows, do work best with felt or felted wools. Chenille projects, such as the Instant Drama Chenille Boa, need flannel. There are also some projects that are especially nice in textured or pile fabrics such as Alexander Lion and the Over in the Meadow Landscape Rug, but can certainly be made in quilting fabric.
Aside from building sewing skills, why do you feel that it is important to include children in craft and sewing projects?
I believe there is a special joy in making. Whether it is baking a cake, building a bird-house, painting a picture, or writing a story. There is something so profoundly fulfilling about making. I see it in the eyes of my own kids and on the faces of my students. There is a light that glows from the process of creation that I think is essential for children.
As a parent, what do you feel is the most important rewards of crafting with your children?
We are a stubborn bunch so it can be rough going making things with my kids. But it also brings great rewards! They always show me new ways of working and thinking about projects. Making is my way playing so I love sharing that with my kids. These are the memories they will have of their childhood and go beyond their time with me. Recently my two girls went to spend a day with my parents. My older daughter spent the day baking and decorating a cake with my mother. My younger daughter wanted to make a play panini maker with my father, who is a woodworker. They spent the day in the wood shop, minus a trip to the hardware store to buy the hinges. Everyone had a very good day!
Thank you to Deborah for taking the time to chat with us.
Sew Fun in available from Interweave, from Amazon, and please check in with your local quilt shop to ask if they are carrying it as well.
Then, clear your schedule and spend some fabulous time sewing with and for the children in your life. Don't have children? Then spend some time sewing with your own inner child instead.