I'm a recent graduate EE student and this is my attempt to gain experience and strengthen my resume so I'm eager to figure this out. I'm designing a dual channel floating output bench power supply that will supply 0-32V @ 5A with CC and CV operation modes. I intend on this being a long-term solution so I'm aiming for good power efficiency with a clean output signal. The safety and protection features I plan on including are a microcontroller based emergency thermal shutdown, reverse current protection, overvoltage protection, and of course a fuse. At first I intended on creating it using IC voltage regulators: switching pre-regulation + second stage linear regulation. My plan was that the switching output would match the linear output to minimize power loss in the linear regulator. The problems with this are wildly varying CC under load and difficulty finding regulators with the desired specifications. Having decided to check out the few schematics for commercial bench power supplies that I could find, I noticed that they don't seem to use IC voltage regulators at all! This leads me to wonder if it would be easier to create the linear regulator portion with discrete components instead of ICs. I've been having trouble finding resources which discuss the best methods of PSU design so I wanted to come here for a second opinion. Which method do you think is the best for me to create my desired product? Switching + linear, switching + discrete or something else?  The post here  poses the same question but it doesn't look like there was an answer to the actual question. I looked at it and it seems like they just discussed the safety of using a negative reference voltage.
After using the simple LM317 on breadboard variable power supply for a while, a need for a more rugged and reliable bench power supply has arose.    Short on money, i decided to build it as many other amateurs like me did. The thing is that, for my current needs i don't need a giant digitally controlled multi-channel 500 watt beast or something like that.  Instead what i really want is a low wattage positive and negative low voltage ouput -12v-0v-12v for example. However i really like that my power supply to be safe, reliable and fool-proof as far as possible. So after searching the web here and there, i found many designs that from my point of view fell in one of two divisions:-   Ones that use discrete op-amps and transistors. And ones that use integrated voltage regulators.   So -at least for me- i think that the ones with discrete op-amps and transistors are more prone to malfunctions and issues compared to the integrated ones with all of their internal over current and thermal protection circuits which would need to be discretely implemented in the bench power supplies that utilize discrete op-amps, however those designs have the advantage of ease of customization and more importantly that it is easier to have 0V output compared to 1.2V in integrated voltage regulator ones.    So i like advice to help me choose between circuits that utilize discrete op-amps like this circuit for example:-  Or ones that use integrated voltage regulators with their intrinsic robustness and low form factor.    Also as a side but related question i have seen many designs on the web that utilize negative voltage fed to the adjust or like pins to achieve 0V output from integrated voltage regulators like this single positive power supply:-     Or a positive and negative channels power supply that i really like its design because of simplicity (not because of laziness but to avoid the drawbacks that may come with complex designs especially when implemented by an amateur like me):- And the question is      Is it wrong or a system safety and reliability lowering act to feed negative voltage to adjust pin for LM317 for example?     I ask this question because the datasheet clearly states that the working output range is 1.2V-37V for LM317 for example, also no similar circuit is mentioned in the Typical Applications section except for the following one:- And even in that circuit, however the adjust pin is tied to the negative rail, it does't regulate during this interval instead it is shut until the next half wave at least that what i understand.    So at last to sum it up which alternative is best suited for my needs, its pros and cons and suggested circuits if possible.
What do spacelike, timelike and lightlike spacetime interval really mean? Suppose we have two events $(x_1,y_1,z_1,t_1)$ and $(x_2,y_2,z_2,t_2)$. Then we can define $$\Delta s^2 = -(c\Delta t)^2 + \Delta x^2 + \Delta y^2 + \Delta z^2,$$ which is called the spacetime interval. The first event occurs at the point with coordinates $(x_1,y_1,z_1)$ and the second at the point with coordinates $(x_2,y_2,z_2)$ which implies that the quantity $$r^2 = \Delta x^2+\Delta y^2+\Delta z^2$$ is the square of the separation between the points where the events occur. In that case the spacetime interval becomes $\Delta s^2 = r^2 - c^2\Delta t^2$. The first event occurs at time $t_1$ and the second at time $t_2$ so that $c\Delta t$ is the distance light travels on that interval of time. In that case, $\Delta s^2$ seems to be comparing the distance light travels between the occurrence of the events with their spatial separation. We now have the following definitions:  If $\Delta s^2 &lt;0$, then $r^2 &lt; c^2\Delta t^2$ and the spatial separation is less than the distance light travels and the interval is called timelike.  If $\Delta s^2 = 0$, then $r^2 = c^2\Delta t^2$ and the spatial separation is equal to the distance light travels and the interval is called lightlike.  If $\Delta s^2 &gt;0$, then $r^2 &gt; c^2\Delta t^2$ and the spatial separation is greater than the distance light travels and the interval is called spacelike.   These are just mathematical definitions. What, however, is the physical intuition behind them? What does an interval being timelike, lightlike or spacelike mean? The following code uses the etoolbox package to convert a list a,b,c into an internal list (called \mylist) and then typesets that with colons: a:b:c:.  However, when I load the etextools package (by uncommenting the second line), I get no list output.   \documentclass{minimal} \usepackage{etoolbox} %\usepackage{etextools} \begin{document} A list: \def\mylist{} \forcsvlist{\listadd\mylist}{a,b,c} \def\do#1{#1:} \dolistloop{\mylist} \end{document}   I suspect it is is a bug since etextools claims to depend on etoolbox.  Is this a bug or am I doing something wrong?  In either case, how can I use \dolistloop with  etextools (which I want for goodies like \expandnext)?  Notes   \show\mylist produces the same output a|b|c| in both cases, so the problem is with \dolistloop which expands to \forlistloop\do The \forlistloop command becomes substantially more complicated when etextools is used.  might be relevant (but not obviously). Show that $e^{-\beta} = \frac{1}{\sqrt{\pi}} \int_{0}^{\infty} \frac{e^{-u}}{\sqrt{u}} e^{-\beta^2 / 4u} du$. Show that $e^{-\beta} = \frac{1}{\sqrt{\pi}} \int_{0}^{\infty} \frac{e^{-u}}{\sqrt{u}} e^{-\beta^2 / 4u} du$.  I'm not really sure of how I should proceed to show this, and it's pretty un-intuitive as well.  I've managed to manipulate the RHS into  $$\frac{e^{4\beta}}{\sqrt{\pi}} \int_0^\infty \frac{1}{\sqrt{u}} e^{-(\beta+2u)^2/4u} du$$ which now vaguely resembles a Gaussian. However, substituting $v = \beta + 2u$ in in order to to get something like $e^{-x^2}$ doesn't particularly help. I got $$ \frac{e^{4\beta}}{\sqrt{2\pi}} \int_0^\infty \frac{1}{\sqrt{v - \beta}} e^{-v^2/2(v-\beta)} dv. $$  I'm really unsure of how I should proceed; any help would be appreciated. Can a lambda function call itself recursively in Python? A regular function can contain a call to itself in its definition, no problem.  I can't figure out how to do it with a lambda function though for the simple reason that the lambda function has no name to refer back to.  Is there a way to do it?  How? 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I can see that such syntax is provided by ES6 and is used widely by Salesforce itself, however, it is not possible to use the following syntax in LWC:   import * as schema from '@salesforce/schema'   import * as label from '@salesforce/label'   or this syntax  import {label, schema} from '@salesforce';   since both versions generate error     LWC1512: Missing resource value for @salesforce"   or      LWC1512: Missing resource value for @salesforce/label   Is there a way to load every label data and every SObject description data using only Javascript without any Apex Server-side code?  By the way, if we look as Salesforce Playground we could notice that   the same syntax is used to import everything from lwc  import * as Engine from 'lwc';   however, if we try to insert such line into any of Lightning Web Component, we would receive the following error     LWC1001: Invalid import. 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Show timestamp of a vote in the tooltip when mousing over it How do I autohide the top panel in Unity? When windows are not maximized, the top panel is basically wasted space for me in Unity.  Is there a way to make it autohide? i.e. make it appear on mouse over. Does a finally block always get executed in Java? Considering this code, can I be absolutely sure that the finally block always executes, no matter what something() is?  try {       something();       return success;   }   catch (Exception e) {        return failure;   }   finally {       System.out.println("I don't know if this will get printed out"); } How do I properly clean up Excel interop objects? How to show path-connectedness of $GL(n,\mathbb{C})$ Well, I am not getting any hint how to show $GL_n(\mathbb{C})$ is path connected. So far I have thought that let $A$ be any invertible complex matrix and $I$ be the idenity matrix, I was trying to show a path from $A$ to $I$ then define $f(t)=At+(1-t)I$  for $t\in[0,1]$ which is possible continous except where the $\operatorname{det}{f(t)}=0$ i.e. which has $n$ roots and I can choose a path in $\mathbb{C}\setminus\{t_1,\dots,t_n\}$ where $t_1,\dots,t_n$ are roots of $\operatorname{det}{f(t)}=0$, is my thinking was correct? Could anyone tell me the solution?