I am working on a project where I have to monitor Vehicle fuel levels using an ADC of a micro controller. My fuel signal is a 0-12V signal &amp; my 10 bit ADC is 0-3.6V range. I have 2 questions :-   Is only putting resistor divider for 0-12V to 0-3.6V sufficient? Do I need to take care of anything else here? How do I calculate resolution of 10 bit ADC after I drop down the voltage as mentioned in point 1 using a divider circuit?
I am working on a BLDC sensorless motor. I need to detect BEMF Zero-cross event. My Motor is working on 24 Volt power.  Now I need to detect the back E.M.F. As refered in .  My MCU is working on 5V. And ADC range is 0 to 5V. I need to convert the BEMF feedback signal to ADC channed in this.  As we know voltage divider rule says:   In Figure I :-- Now signal (U) which I need to feed is applied at the middle of the two resistors R1 &amp; R7. So what is the value of voltage VU ?   In Figure II :-- Sum of U,V,W  is applied at the middle of the two resistors R11 &amp; R15. So what is the value of voltage VN ?  Also, what are the roles of capacitors C1 &amp; C4?  Please can someone explain the MATH behind this ?
All Stack Exchange data dumps There are two directories shown by 'ls'.  Normally directories anywhere are blue on black background.  But the first one is blue on green and impossible to read.  Why is this?  How to make it blue on black, or at least something light on something dark?  This is on Ubuntu 12.04, using bash in Gnome Terminal.  In Konsole, the blue is slightly darker, and possible to read, though could be way better. Foreign words reborrowed back into English Wikipedia mentions several English words that have been :   Anime comes from animation and has been reborrowed into English to mean Japanese-style animation. Puroresu comes from professional wrestling and is a term for Japanese-style professional wrestling. Kosupure comes from cosplay (an abbreviation of costume play) and refers to the practice of dressing in costumes of anime and video game characters.    Do you know other examples of word reborrowings from Japanese or other languages back into English, or vice versa? How do I run a batch file from my Java Application? In my Java application, I want to run a batch file that calls "scons -Q implicit-deps-changed build\file_load_type export\file_load_type"  It seems that I can't even get my batch file to execute. I'm out of ideas.   This is what I have in Java:  Runtime.    getRuntime().    exec("build.bat", null, new File("."));   Previously, I had a Python Sconscript file that I wanted to run but since that didn't work I decided I would call the script via a batch file but that method has not been successful as of yet. Can Git hook scripts be managed along with the repository? We'd like to make a few basic hook scripts that we can all share -- for things like pre-formatting commit messages.  Git has hook scripts for that that are normally stored under &lt;project&gt;/.git/hooks/.  However, those scripts are not propagated when people do a clone and they are not version controlled.    Is there a good way to help everyone get the right hook scripts?  Can I just make those hook scripts point to version controlled scripts in my repo? What Is Exponentiation? What are independent parameters in Hellmann–Feynman theorem? A typical example in textbooks about the application of Hellmann–Feynman theorem is calculating $\left\langle\frac{1}{r^2}\right\rangle$ in hydrogen-like atoms.  has a nice demonstration of this. At some point in the Wikipedia derivation is used that $$\frac{\partial n}{\partial \ell}~=~1. \tag{1}$$   But why is eq. (1) true? I know that  $$n=n_r+\ell+1,$$   but $n_r$ is just another variable with different physical meaning, so why is $n_r$ independent from $\ell$, whereas $n$ is not? The Wikipedia proof for Hellmann–Feynman theorem does not address the problem of independence of different parameters. What variables are kept fixed during the differentiation $(1)$ and why?  The Wikipedia page seems to have only a vague notion of $\frac{\partial\hat{H}}{\partial\lambda}$ and $\frac{\partial E}{\partial\lambda}$, unlike in, e.g., thermodynamics, where all partial derivatives are typically written like  $$\left( \frac{\partial U}{\partial V} \right)_S \qquad ,\qquad  \left( \frac{\partial U}{\partial V} \right)_p \qquad ,\qquad  \ldots $$ so that it is clear which variables are kept fixed during the differentiations. How is stock price determined? Is stock price determined only by the last trade that takes place?  For example, if a stock I own is trading at $3.42, and I place a Sell Limit order for $0.00, will the stock price temporarily dip to $0.00?  Likewise, if I place a Buy Limit order for $100.00 for a stock that is trading at $1.23, will the price spike to $100.00?  Is there some sort of "average price" that is reported on the stock ticker?  Thanks for your help in understanding this! How does Fermat's principle make light choose a straight path over a short path? This is a thought experiment where I have made a &quot;C&quot; shaped hole inside diamond. The refractive index $(\mu)$ of diamond is 2.45. Say we shine a laser from top of the &quot;C&quot; as shown. My calculations show that light reaching A can reach B in the least possible time if gone through the &quot;C&quot;. but I'm pretty sure the perpendicular laser beam travels undeflected and straight down. Though I don't have experimental evidence, I see something wrong either with my intuition or with the theory. It would be great if someone could clarify. *       'a' in the diagram is the thickness of the cutout and all comparable distances can be taken 'a'. I've been having trouble getting my server to send email and I haven't for the life of me figured out how to fix it. If anyone could give me some simple pointers, that would be muchly appreciated!  May 19 15:36:03 ubuntu-12 sm-mta[2484]: s4JFa3jp002484: from=&lt;www-data@ubuntu-12.04-     production&gt;, size=412, class=0, nrcpts=1, msgid=&lt;201405191535.s4JFZw4c002483@ubuntu-12.04-  production&gt;, proto=ESMTP, daemon=MTA-v4, relay=ip6-localhost [127.0.0.1] May 19 15:36:03 ubuntu-12 sendmail[2483]: s4JFZw4c002483: to=myname@mycompany.com, ctladdr=www-data (33/33), delay=00:00:05, xdelay=00:00:05, mailer=relay, pri=30123, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (s4JFa3jp002484 Message accepted for delivery) May 19 15:36:03 ubuntu-12 sm-mta[2487]: s4JFa3jp002484: to=&lt;myname@mycompany.com&gt;, ctladdr=&lt;www-data@ubuntu-12.04-production&gt; (33/33), delay=00:00:00, xdelay=00:00:00, mailer=esmtp, pri=120412, relay=mailserver.mycompany.com. [213.171.216.115], dsn=5.0.0, stat=Service unavaila$ May 19 15:36:03 ubuntu-12 sm-mta[2487]: s4JFa3jp002484: s4JFa3jp002487: DSN: Service unavailable May 19 15:36:03 ubuntu-12 sm-mta[2487]: s4JFa3jp002487: to=&lt;www-data@ubuntu-12.04-production&gt;, delay=00:00:00, xdelay=00:00:00, mailer=local, pri=30000, dsn=2.0.0, stat=Sent Get variable from PHP to JavaScript I want to use a PHP variable in JavaScript. How is it possible? Isomorphism equivalence implies fundamental group is abelian How do I recover my old Clash of Clans (COC) game save & base? I unintentionally and stupidly wiped my Clash of Clans game data. I went to Application Manager on my Android and clicked 'Clear data'. (I used this for fixes before and it never started a new game.)   Now, my level 60 or so base has been wiped as if was to start a new game. Have I doomed myself to starting again or is there a way in which I can retrieve my old game save? Maybe by contacting Supercell? I have a snapshot of my base. Windows 10: Pin an item to left side of Start Menu? How do I assign the output of a command into an array? Where can I see my flag count / history? Is there a section or page that lists my flag count and / or history? This is exercise 1.6.1 of   Suppose that 501 distinct integers are selected from 1 . . . 1000. Show that there are distinct selected integers $a$ and $b$ such that $a | b$. Show that this is not always true if 500 integers are selected.  This seems like it should be simple but it's has been stumping me for a few days.  Here's my idea for a proof:  Let $S$ be a set of 500 distinct integers between 1 and 1000 that don't divide each other. Let $S_{1-500}$ and $S_{501-1000}$ partition $S$ into sets containing the elements ≤ and > than 500, respectively. Then consider $2 S_{1-500}$ and $\frac{1}{2}S_{501-1000}$, the result of multiplying the elements of these sets by 2 and 1/2, respectively. Because elements of S are coprime, $S_{1-500}$, $S_{501-1000}$, $2 S_{1-500}$, and $\frac{1}{2}S_{501-1000}$, are disjoint. Also note that each of these sets is a subset of the integers from 1 to 1000. One can deduce that the cardinality of the union of these sets is 1000, and therefore they form a partition of the integers from 1 to 1000.  Now, I know this demonstrates that you can't add another number to $S$ that is coprime with all the elements in $S$, which means that a coprime subset of the integers from 1 to 1000 can have at most 500 elements. Can someone articulate why this is true for me? Also, this was in a section on the Pigeonhole principle, can someone rework the proof to utilize that, and possibly make it simpler? Thanks. Situation: when a user self-marks their post as a duplicate, it shows as closed by "community" rather than the original poster.  Problems: this is not clear at all to most users of SE what has happened. It looks like the question was "mod closed" as a duplicate against the asker's wishes.    Suggestion: instead of the community user "closing" the post, have the final close user be the asker (or make it "Community &amp; Asker"). This will help clear up confusion and streamline the process for understanding what happens. Best program to trim silence beginning and end of mp3 files? I have a bunch of mp3 files that have silence at the beginnings and ends, is there any program to trim this automatically? I would prefer that I can just give it a list of files to trim as opposed to having to do them individually. Show that for any prime $ p $, there are integers $ x $ and $ y $ such that $ p|(x^{2} + y^{2} + 1) $. So we obviously we want $ x^{2} + y^{2} + 1 \equiv 0 ~ (\text{mod} ~ p) $.  I haven’t learned much about quadratic congruences, so I don’t really know how to go forward. I suppose you can write it as $ x^{2} \equiv -1 - y^{2} ~ (\text{mod} ~ p) $, but again, I’m not sure where to go. I know about the Legendre symbol and quadratic residues, which I know are involved in this question, but I don’t know how to apply what I know. :(