Supposing I want to measure 1-5A over a range of 1-40V on an ammeter, should I change the shunt resistor every time the voltage changes so that the voltage drop across the shunt resistor stays the same?  If yes, how do ammeters on lab bench power supplies work over a wide range of voltages?
I have the following ammeter:   The seller recommends 75mV 100A shunt be placed with it. I want to know what will happen if I change the voltage going through the shunt. Should I be changing the shunt as well to read amps correctly?   I want to build a 1-40V (or maybe 50V) adjustable DC power supply and use this ammeter to measure current. What the right value of shunt that I should use to get the right measurement? Changing shunts in a lab bench power supply is impractical, of course.  EDIT: I am planning to measure only up to 5A or so. Sorry I forgot to mention this previously.
How do I prove that a graph is a topological manifold Did anyone in the Star Wars universe wear effective armour? The Storm Troopers are the main case here, they get killed easily by blasters and even the Ewok arrows go straight through their 'armour'.   The AT-ST and AT-AT use armour to repel blasters of different strengths so they don't pass through all materials. I understand though that the armour used on these is likely much heavier.   From the prequel trilogy we also have the , which have a shield when not moving. Does anyone other than these droids use this technology?   You may use any of the Scrapped EU, Current EU and the normal U to answer. How can I remap keyboard keys in windows 8.1? I'm looking for a simple utility which will modify registry and would not require running at startup. I tried sharpkeys but, it does not seem to work in windows 8.1. Any other suggestions? Or a simple how-to tutorial for windows 8.1?  Edit: Keytweak isn't working either. 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Currently, I have the following data frame (model_data):  Road Id Vehicle_id  entry_time           exit_time          1        1        2017-01-31 00:00:00  2017-01-31 00:00:00 last_veh_time  vehicle_type     status 300            4 wheel          0    Likewise, I have the information (nearly a million rows) of all the vehicles entering a place and exiting the same place.  Status can be either $1$ or $0$ for all of these.  last_veh_time is the last vehicle passed the same place before how much time.    I want to know the probability of a getting status $0$ for a vehicle based on the entry_time and last_veh_time. To do this, I created the model:   model = glmer(status ~last_veh_time + (1 |link ),               data=model_data, REML=FALSE)   Is this the right approach?  Any help is appreciated. What does 'apt-get install update' do? I saw this snippet in some installation instructions:  $ apt-get install update   I know what apt-get install XXXX does and I know what apt-get update does, but I can't find any info on what this combined statement does. What does it do? Flag counter is missing sporadically I noticed that on both sites where I am a moderator the flag counter is occasionally not showing any flags even when there are flags in the queue. A refresh of the page leads to the correct flag count to be displayed. I noticed this happening when I visited the site for the first time in a few hours, when I was recently active on the site the counter seems to stay accurate. Can I use my laptop as a second monitor? Is it possible to make my laptop's screen act as a second monitor for my desktop computer? How do I install Firefox 52 ESR on 16.04? This  asks how to install FF32 bit while keeping the 64 bit.  I want the much more simple thing: is there a canonical way to install firefox 52 ESR as "default" firefox in my 16.04?  I found this  ... but there are no packages; probably no wonder given the fact that the linked blog article dates back to 2012.  So, 2017, Ubuntu 16.04; how to install FF 52 ESR (as I simply need the java plugin to work for me).  ( my current solution: I downloaded the TAR file from mozilla, extracted that to /opt; and then changed /usr/bin/firefox to be a link to that ESR version of firefox. works, but ugly ) Can I use the Adwaita theme in Unity without installing GNOME shell? I recently installed Ubuntu 11.10 (new install). I would like to use the Adwaita theme with Unity, but it seems that it is not available in the theme selection dialog. I know I get it there after installing gnome-shell, but is there a way to use Adwaita theme for Unity without installing gnome-shell? Let $a&gt;0$ and $f: \mathbb R \rightarrow \mathbb R$ with a property $\forall x,y \in \mathbb R;$ such that $0\;&lt;\;y\;-\;x\;&lt;\;a$ $$f(x)\;&lt;f(y).$$ Prove if the statements are true or false:  $1)$ $f$ must be injective.  $2)$ $f$ must be surjective.  I tried to use a quarter of a circle with radius $r=a$ or a right-angled triangle and translate it. When I moved it, I saw new values of $f$. I concluded the maximum value in the previous interval can't appear again in another interval when the distance between one point in the first interval and one point in the second is less than $a$. I also considered using an absolute value function, but I haven't done anything. I think, but I haven't proven it, that the function must be bijective. A cyclic group is a group that is generated by a single element.  That means that there exists an element $g$, say, such that every other element of the group can be written as a power of $g$.  This element $g$ is the generator of the group.  Is that a correct explanation for what a cyclic group and a generator are? How can we find the generator of a cyclic group and how can we say how many generators should there be? Difference between $\Delta$, $d$ and $\delta$ I have read the thread regarding , but it does not answer my question.  I am confused about the notation for change in Physics. In Mathematics, $\delta$ and $\Delta$ essentially refer to the same thing, i.e., change. This means that $\Delta x = x_1 - x_2 = \delta x$. The difference between $\delta$ and $d$ is also clear and distinct in differential calculus. We know that $\frac{dy}{dx}$ is always an operator and not a fraction, whereas $\frac{\delta y}{\delta x}$ is an infinitesimal change.   In Physics, however, the distinction is not as clear. Can anyone offer a clearer picture? Is transferring to another university an option for an unhappy PhD student?