I used the LM337 negative regulator to regulate a +12V from a PC power supply. And connected the GND to input and the +12 to ground of the circuit, and i got it work (i mean it's regulating the voltage) but the problem is it's get very hot even with heat sink connected to it. Is that normal because i didn't keep it on for a long time. It used to regulate 12 volts to 3.2 volts.
I'm using a 5 V / 2 A voltage regulator () without a heatsink. I'm testing the circuit with a microcontroller (PIC18FXXXX), a few LEDs and a 1 mA piezzo buzzer. The input voltage is aprox. 24 VDC. After running for a minute, the voltage regulator starts to overheat, meaning it burns my finger if I keep it there for more than a second. Within a few minutes it starts to smell like it's burnt. Is this a normal behavior for this regulator? What could cause it to heat that much?    Other components used in this circuit:  L1:   R2:   F1:
Something I did in the first Animal Crossing was make a house on an alternate character solely to showcase bugs/fish I felt were too cool to only leave in the museum. However bugs can't be mailed or dropped, so I'm at a loss as to how to do this.  Is there a way I can give bugs/fish to a second character or will that character have to find them themselves? I need help running python in ubuntu  I can run python without a problem in my terminal but when I create a .py file I can't get it to run. How do I reference an alias in a WHERE clause? I tried a couple of substitutions but have so far gotten nowhere. Can anyone guide me in the right direction? Thanks for your time. Limit the post for differents custom post type in the same wp_query I have three custom post type:    books magazine videos   Now i want to limit the number of post for custom post type, for example:   books => 3 post magazine => 2 post videos => 1 post   I used a query post like this:  query_posts( array(     'post_type' =&gt; array(     'books',     'magazine',     'videos' ), 'paged' =&gt; $paged, 'posts_per_page' =&gt; 6,  )); $counter = 1; if (have_posts()) :     while (have_posts()) : the_post();   if (($counter == 2) || ($counter == 3) || ($counter == 4)) {         $div = 'alpha';     } elseif(($counter == 6)) {         $div = 'omega';     } else {         $div = '';     }   The problems is i cant limit the numbers by custom post type.  Any idea?  Thank you :) Where can I find a list of computers guaranteed to work with Ubuntu? Before I buy my next laptop, I'd like to make sure that it will work perfectly with Ubuntu. Is there a list of completely supported computers anywhere? Packet Tracer 7 on Ubuntu 18.04 cannot launch I am having some issues with Packet Tracer 7 on Ubuntu 18.04: when I launch it with ./PacketTracer7 within the /opt/pt/bin directory, it opens but close immediately with a lot of:     "Warning: libpng warning: iCCP: known incorrect sRGB profile"   error msgs on the console.  The thing is, I installed PacketTracer7 on Ubuntu 16.04 and I remember that I had that issue with the libqt5multimedia.so.5 dependency, but I was able to find the solution (thanks to askubuntu and google) by installing the dependencies. So, everything perfect with 16.04.  But I'm a bit lost now. I can't realize where the issue come from, because I know the qt5 libs are installed on the system.  This is what I see when I run dpkg --get-selections:  libqt4-xmlpatterns:amd64            install libqt5concurrent5:amd64             install libqt5core5a:amd64              install libqt5dbus5:amd64               install libqt5gui5:amd64                install libqt5multimedia5:amd64             install libqt5multimediaquick-p5:amd64          install libqt5multimediawidgets5:amd64          install libqt5network5:amd64                install libqt5opengl5:amd64             install libqt5opengl5-dev:amd64             install libqt5positioning5:amd64            install libqt5printsupport5:amd64           install libqt5qml5:amd64                install libqt5quick5:amd64              install libqt5quickparticles5:amd64         install libqt5quicktest5:amd64              install libqt5quickwidgets5:amd64           install libqt5script5:amd64             install libqt5scripttools5:amd64            install libqt5sensors5:amd64                install libqt5sql5:amd64                install libqt5sql5-sqlite:amd64             install libqt5svg5:amd64                install libqt5test5:amd64               install libqt5webchannel5:amd64             install libqt5webkit5:amd64             install libqt5webkit5-dev:amd64             install libqt5widgets5:amd64                install libqt5x11extras5:amd64              install libqt5xml5:amd64       I've tried to uninstall pt and the qt5 libs and install everything again, but nothing... the same issue.  Did anybody install PacketTracer7 on Ubuntu 18.04?  I would be very happy to have your help for doing it!  Thanks and forgive me for my poor english :) Does Microsoft Office 2010 have version control?  In other words, does it automatically save old versions of files? Preventing robots from crawling specific part of a page Why did the Tethered form a line in Us? In Jordan Peele's  we see that the Tethered plan a revolt, rise above ground and start murdering everyone in sight and then they form a line by holding hand in hand.   What was the purpose of that? Can you create a strong blockcipher with small blocksize, given a strong blockcipher of conventional blocksize? Suppose I want a strong 20-bit blockcipher.  In other words, I want a function that takes a key (suppose the key is 128 bits), and implements a permutation from 20 bits to 20 bits.  The set of permutations should be close to a randomly-chosen subset of size $2^{128}$ of all $2^{20}!$ permutations on 20 bits.  I don't want you to build a new blockcipher from scratch.  Instead, assume you have a "strong" blockcipher like AES (128-bit blocksize, 128-bit keysize) and use this to build your 20-bit cipher.   Of course, your construction should be practical (i.e., you should be able to run it in both directions with reasonable amounts of time and memory). In his first lesson (transcripted in "Tips on Physics"), Feynman talks about math for physicists in a very cool and practical way. And at the end of the section he talks something like "so the first thing to do is to learn to learn derivative, integral and algebra" (I don't know how much precise I'm being because I've read it in Portuguese). I would to know if there is some book that deals with math as Feynman did it in this lesson (respecting formalities, but teaching how to use the practical rules)? Also, someone have any recommendations for algebra book (college level)? My host is x64 bits Windows 8.1.  I downloaded the latest Virtual Box (4.3) and I'm trying to create a VM with a 64 bits Ubuntu OS (ubuntu-12.04.3-desktop-amd64).  When I go to New VM wizard, it doesn't give me option to select "Ubuntu (x64)" as I have seen in other people's screenshots, only just "Ubuntu". As a result, the ISO can't boot. I tried in another PC and Virtual Box gives the x64 variants to most listed OS...  Control Panel shows x64 OS, x64 processor. My host laptop is a Sony Vaio VPCZ22UGX/N, Intel® Core™ i7-2640M processor. CPUz shows Vx-t is available on my processor, of course.  Here is what I tried so far:   I enabled IO APIC as required in the docs. I have virtualization enabled in the BIOS. It works fine in VMware. Check that Hyper-V is not running or even installed on my Windows. Same for VMware. I also tried running the command:  VBoxManage modifyvm [vmname] --longmode on    for that VM, but no change.. I think the issue is really that I can't select x64 variant of the Ubuntu OS for that VM. Other people seem to indicate that's a requirement, but I don't get that option for some reason.  I spent a lot of time and can't find what's wrong... Anyone knows what could be missing here?  Thank you very much!!  Eduardo Why have header files and .cpp files? Why does C++ have header files and .cpp files? Why is shape with shrinkwrap modifier flat? The legacy tray (see the screenshot below) will be removed in GNOME 3.26. I want to wean myself off it before the change arrives in Ubuntu (17.10 or 18.04).    Can I disable the legacy tray in Ubuntu GNOME 17.04? I was recently asked to find the accumulation points of the set $$S = \{(-1)^n + \frac{1}{n} \mid n \in \mathbb{N}\}$$  I answered that the accumulation points are $\{-1,1\}$, because despite the fact that $\frac{1}{n}$ diverges, we can still use $\frac{1}{n}$ to find an element arbitrarily close to either $1$ or $-1$, i.e. to show that there is an element in an arbitrarily small neighborhood of $1$ or $-1$. (No proof was required for this question --- this is my intuition.)  Am I right at all? Metapost label based on variable value I want to label a scale based on a variable value and I wrote a metapost code like this.  $ := 1; for i = -.3cm step .6cm until 3.6cm:     label.bot(str$,(i,-3.7cm));     $ := incr($); endfor;   It just labels "$" instead of its value. How to output the variables value? I don't have any knowledge in hardware and would like to know which RAM should I buy for my laptop.  How do I discover what RAM I need &amp; how much my machine can take?  I have a Razer Blade 15 (RZ09-02705F76) 2018 but don't know if there is a specific type or format of RAM that suits it and don't know where to find this information. \textcite macro produces "Author (year)" correctly but colours first paren with hyperref