loading

I was tired of looking for the correct transformer or the right pack of batteries just to try out some electronics and buying a Lab PSU costs a lot of money so instead of converting a PC ATX or a LED Switching PSU, I thought why not plug "something" in front of it which could stop any mistakes like a short-circuit, allowing a variable voltaje and setting a max current to my project.

Step 1: How It Works

One of the cool things about having this "device" separated (besides of not destroying a PSU) is that you can switch between a transformer or another power source in no time really.

Another feature is you can create more than one of this and plug them into same PSU (as long as the power of the PSU is enough for all) and you'll get different outputs to work with from same source.

<p>This is a super project and one that most of us need quite often. I would suggest either a fuse or a circuit breaker to prevent a flammable possibility.</p>
<p>hey thanks </p><p>The protection is coming from the step-down converter it has for short-circuit and overload too. ;)</p>
<p>This project look like very usefully </p><p>Can I set max current apply any load This device? (when I can set current limit? on load or before apply voltage? )</p><p>Thanks.</p>
hey thanks.<br>So &quot;any load&quot; will mainly depend on the step-down bucket converter you buy. <br>About the current limit is a good question, you cannot see what is the current limit until you have a load in there so what I do is get the current all the way down, put the load and start increasing the knob so I'll see where is getting for the current voltage pre set and I can stop anytime.
<p>Quite easy and good for most needs.</p><p>For me, a Lab supply has to go down to 0V and needs a current limiting function.</p><p>I know, that you will need a auxillary negative supply for achieving it. Most people don't go this far.</p>
<p>0V? 0.what?</p>
<p>thanks man, yeah I'm not too deep in electronics yet (it's a hobby for me) so my current needs are much easier to achieve :)</p>
<p>This setup is unable to give you something like 24V 350ma . You will need to add as good heat sink on the regulator. Otherwise it will activate the internal thermal shutdown.</p>
<p>yup you'r right good catch! I haven't gone into that case yet but I think there is enough room inside the box to get a good heat sink for the regulator. </p><p>If I get there I'll give the update here for sure.</p><p>thanks!</p>
<p>If you series a 10K with a 1K the 10K will give a 'coarse' adjustment and the 1K will give a 'fine' adjustment, to use set the 1K @ center, get in the ballpark with the 'coarse' 10K, then adjust more finely with the 'fine' 1K and life is good</p>
<p>wow I had no idea that existed, <a href="http://www.h4ck.de/content/CFPoti/CFPoti.html">this</a> seems to be a good resource to try it out, thanks!</p>
<p>NICE,</p><p> I made a portable 6400mAh 4,5V to 29.5V output.</p><p>And if i need lower voltage i also made ( the smallest power supply on the world)</p><p>to hook it on too.</p><p>maybe you can do that also to make it more usable all round.</p><p>Look,</p><p><a href="https://www.instructables.com/id/Portable-Wireless-Power-Supply-and-Phone-Charger-4/">https://www.instructables.com/id/Portable-Wireless...</a></p><p>WannaDuino!!! STYLE.</p>
<p>nice build, I got a comment from supernoodle2014 with the idea of getting a battery as psu to make it portable, you got just that :)</p>
<p>I have been looking for something like this a long time! Great!</p>
<p>thanks!</p>
<p>Nice. You can also connect it to a battery and make it portable.</p>
<p>that's great idea! and one of the points of creating it without psu (you can connect to any powers source :D ), thanks!</p>
<p>I'm going to build this great idea.</p><p>I'm going to use multi turn linear potentiometer for more accuracy.</p><p>Thanks a lot.</p>
<p>awesome! please share it when you get it. </p><p>A multi turn is a good point, I looked for them here but couldn't find any, at least without paying around ARS$200 each (I bought those for ARS$40) </p>
<p>Great Idea, Just what I was looking for</p>
<p>great! if you create something around it please share your build I think it's even better for others to see ideas/ mutations around it in the comments</p>
<p>Very clean, tidy and compact design. Nicely done.</p>
<p>thanks :)</p>
<p>I like it a lot!</p><p>It remembers me part of a project I made:</p><p><a href="https://www.instructables.com/id/Solar-Charger-and-Adjustable-Power-Supply/">https://www.instructables.com/id/Solar-Charger-and...</a></p><p>But with a great better case!</p><p>I love it!</p>
<p>oh your 'ible is awesome!, thanks</p>
<p>One note.. If you do make more then one for different voltages on a project, they will all have a common ground IE say charging battery cells in series you cant set the voltage for each cell to do a balance charge. But this is a nice project and good share.</p>
<p>oh that's a good point, I haven't really think about this one as a battery charger but yeah if you'r gonna use same PSU for more than one you'll get same ground for them, maybe for that case just using another power source for each charger idk</p>
this work to control the power of a tool like a cheap rip-off dremel (I'm this case the rpm) or the power in a heat gum, glue gun ect?
<p>mm so it will really depend on the current supported of your psu and your step-down, I did some tries with small motors and didn't had any issues so far</p>
<p>This should work in a hot glue gun, but a heat gun has a fan/motor so I'm not sure...</p>
<p>I like the enclosure design. It looks great.</p>
Good one..
<p>Awesome :) This looks great!</p>
thanks :)
te qued&oacute; re bueno!
gracias!
<p>congratulations for the explanation of the project</p>
thanks!!

About This Instructable

35,497views

463favorites

License:

More by pjnovas:Easy and cheap lab regulator for any PSU 
Add instructable to: