I am using a white light LED strip in my 3D printer enclosure. And I would like to use the power supply of my 3D printer to power this LED strip.  The original power supply of the LED strip is 12V/2A The power supply of the printer outputs 12V/25A  Can I use the power supply of the 3D printer to power this LED strip, or will it overheat the LEDs?  Thanks
Power supplies are available in a wide range of voltage and current ratings.  If I have a device that has specific voltage and current ratings, how do those relate to the power ratings I need to specify?  What if I don't know the device's specs, but am replacing a previous power supply with particular ratings?  Is it OK to go lower voltage, or should it always be higher?  What about current?  I don't want a 10 A supply to damage my 1 A device.
Error -504 on appliation installation Yes. I've read all other questions regarding this problem. Like this one:  It's the same problem as this one but with more background information and an other app:   The details: My device is an Ulefone Be Touch 2 running Android 5.0.  My connection is perfect. To be sure I tried different networks, among them are 3G, 4G and wifi on ADSL, VDSL, cable and fiber. I've also used Tor and 3 different VPN providers in 3 countries on 2 continents. Let's say I ruled the network out.   A single app does not install: OpenKeychain.  Currently I have 126 apps installed. It does not install via desktop browser > play store > install button.    I have enough free space (40GB). The app is 7MB.   Re-adding Google account and clearing caches did not work.    Even a complete device wipe and re-install didn't work.     Downloaded the apk and tried manual installation, same error.   I also own a Nexus 7 (2013 wifi) and the app installs fine on that device. In my ~/.bashrc file reside two definitions:   commandA, which is an alias to a longer path commandB, which is an alias to a Bash script   I want to process the same file with these two commands, so I wrote the following Bash script:    #!/bin/bash  for file in "$@"     do     commandA $file     commandB $file done   Even after logging out of my session and logging back in, Bash prompts me with command not found errors for both commands when I run this script.  What am I doing wrong? I just upgraded my texlive distribution and can no longer insert space in table rows using \\[x pt] syntax when colortbl is loaded.  It seems that recent changes to array.sty might be the problem as this is the only package to change recently.  Can anyone suggest a workaround?  MWE  \listfiles \documentclass{article} \usepackage{colortbl} \begin{document} \begin{tabular}{l}   \hline   No space below with \texttt{colortbl.sty} loaded. \\[10mm]   \hline \end{tabular} \end{document}   File versions in use:   article.cls    2014/09/29 v1.4h Standard LaTeX document class   size10.clo    2014/09/29 v1.4h Standard LaTeX file (size option) colortbl.sty    2012/02/13 v1.0a Color table columns (DPC)    array.sty    2018/04/07 v2.4g Tabular extension package (FMi)    color.sty    2016/07/10 v1.1e Standard LaTeX Color (DPC)    color.cfg    2016/01/02 v1.6 sample color configuration   pdftex.def    2018/01/08 v1.0l Graphics/color driver for pdftex For distinct prime numbers $p_1,...,p_n$, what is the Galois group of $(x^2-p_1)\cdots(x^2-p_n)$ over $\mathbb{Q}$?     This problem appears to be quite common, however my understanding of Galois theory is quite poor, and I have no idea how to do this problem. Is it possible to reference an excel cell in a comment? I have an Excel balance sheet with a total at the bottom. On that cell I have a comment that says that the reason the total is X is because of what happens in J2. What happens if I insert another row before that, now my comment is wrong because all the rows jumped up a value.  Is there any way to reference a cell dynamically in an Excel commment? "I let him do it" and "I allow him to do it", why exactly does one require 'to'? how to execute mongo admin command from java I just bought all the ingredients to make a soup in the crock pot. I was planning on having it cook all day, but I just realized the recipe only calls for it to cook on low for 3-4 hours. If I cook it on low for 3-4 hours, and then put it on warm before I leave for work, will it be a bacteria minefield or will it be warm enough to keep the food safe from bacteria? Inline elements shifting when made bold on hover I created a horizontal menu using a HTML lists and CSS. Everything works as it should except when you hover over the links. You see, I created a bold hover state for the links, and now the menu links shift because of the bold size difference.  I encounter the same problem as . However, the post does not have proper solution. I've searched everywhere for a solution and can't find one. Surely I can't be the only one trying to do this.  Does anyone have any ideas?  P.S: I don't know the width of the text in menu items so I cannot just set the width of the li items.    .nav { margin: 0; padding: 0; } .nav li {      list-style: none;      display: inline;      border-left: #ffffff 1px solid;  } .nav li a:link, .nav li a:visited {      text-decoration: none;      color: #000;      margin-left: 8px;      margin-right: 5px;  } .nav li a:hover{      text-decoration: none;      font-weight: bold;  } .nav li.first { border: none; } &lt;ul class="nav"&gt;     &lt;li class="first"&gt;&lt;a href="#"&gt;item 0&lt;/a&gt;&lt;/li&gt;     &lt;li&gt;&lt;a href="#"&gt;item 1&lt;/a&gt;&lt;/li&gt;     &lt;li&gt;&lt;a href="#"&gt;item 2&lt;/a&gt;&lt;/li&gt;     &lt;li&gt;&lt;a href="#"&gt;item 3&lt;/a&gt;&lt;/li&gt;     &lt;li&gt;&lt;a href="#"&gt;item 4&lt;/a&gt;&lt;/li&gt; &lt;/ul&gt; Why am I constantly running out of space on my Galaxy S2? Vector. Properties It is given in a question that $\vec x+\vec a=(\vec a\cdot \vec x)\vec b$ and it is stated that $\vec a$, $\vec b$ and $\vec x$ are vectors.  It is also stated that $\vec a\cdot \vec b\ne 1$.  The question asks to express $\vec x$ in term $\vec a$ and $\vec b$.  How do you this? Changing subject and verb positions in statements and questions We always change subject and verb positions in whenever we want to ask a question such as "What is your name?". But when it comes to statements like the following, which form is correct?        I don't understand what are you talking about.   I don't understand what you are talking about.      Another example        Do you know what time is it?   Do you know what time it is?      Another example        Do you care how do I feel about this?   Do you care how I feel about this? How to partition harddisk for Ubuntu 18.04 I want to partition my hard disk, but I don't have any other software running(like dual booted).  And I do not know how to do it. Can you send the instructions? "You must wear a suit TO an interview" vs "You must wear a suit FOR an interview" In the sentence-     You must wear a suit to an interview   shouldn't the to be replaced by for? Or what's the difference between these two here? Is the following conjecture true?     Given an $n&gt;1$ and a $k$ such that $0&lt;k&lt;n$ then $\gcd\left(\binom{n}{k}, n\right)&gt;1$   This was a question asked in my old Number Theory course that I recently remembered. It was posed after we learned that $p\mid\binom{p}{k}$ for $0&lt;k&lt;p$. We never resolved it either way. I expect it to be true and have an elegant answer, but I haven't been able to prove it. How to compute moments of log normal distribution? The computed moments of log normal distribution can be found . How to compute them? Ubuntu 14.04 Wireless not working: no network interface. Atheros [168c:003e] device What is the angle at which water is splashed when a vehicle tyre rides in water on the road? I would like to know the following:   What is the angle at which water gets splashed when I ride my vehicle through a water on the road? How does angle of water varies with speed? What is the relation between the distance the water goes with the speed of the vehicle?   Thanks! How to change Ubuntu 18.04 system fonts? I installed Ubuntu 18.04, and I want to customize the fonts. I have already change all the setting by tweak tool. But the system default font not be changed, is anything I need to do? Vertically align horizontal inline-block elements