lab psu - Page 1
Forum section: electronics / projects

author: m3vuv
author_rank: Super Contributor
timestamp: January 11, 2021, 10:40:31 am
content: does anyone know of a decent 0-30v psu,say 5 amp controled by an arduino,shematic or project details with code+a lcd display?,cheers in advance m3vuv.

author: Berni
author_rank: Super Contributor
timestamp: January 11, 2021, 10:49:04 am
content: https://uk.farnell.com/tenma/72-2690/bench-power-supply-1-ch-30v-5a/dp/2563982Arduino control possible via the RS232 port on models that support remote control

author: m3vuv
author_rank: Super Contributor
timestamp: January 11, 2021, 11:22:50 am
content: thanks but i wish to build one not but one!,i already have similar that i got as a kit,its 0-30v/02amp,cv/cc,if i could extract the code from the atmel 328 it would be easy but ive no way of doing that,thought there must be sommat on the web that i can modifie with more pass transistors and current sense resistor but cant find anything,im looking for a schematic + the code tbh,cheers anyway.

author: Berni
author_rank: Super Contributor
timestamp: January 11, 2021, 11:40:28 am
content: Then just google one like this:http://linuxfocus.org/English/June2005/article379.shtml#379lfindex4Tho it does not make a whole lot of sense to just clone one from a published project online. Making such a PSU from parts ends up being more expensive than just buying the one in my first post (just the parts, ignoring the work put into putting it together) while getting none of the learning experience or satisfaction of designing your own.Sure nobody designs a PSU from scratch, but the process of looking at other peoples designs and choosing the good parts out of them is a valuable learning experience in its own right. You have to understand how the PSU works in order to decide if you want to copy that part of it. Mix and match enough parts and customize them to make the PSU that works exactly how you want it to.Copying designs 1:1 off the internet is just like buying a kit except minus the convenience of also getting all the parts included. Its a glorified lego kit, you put it together according to instructions and have no idea how it even works. The only time you actually learn anything from a kit is when you put it together and it does not work, forcing you to debug it and dive into understanding how it actually works in order to be able to identify the fault.

author: m3vuv
author_rank: Super Contributor
timestamp: January 11, 2021, 12:20:25 pm
content: dont you think i already know this??!,thanks for your reply but its not very helpfull.

author: Berni
author_rank: Super Contributor
timestamp: January 11, 2021, 01:01:22 pm
content: Quote from: m3vuv on January 11, 2021, 12:20:25 pmThe link above contains a digitally controlled PSU with LCD, showing full schematics, assembly instructions, PCB files, software source code...etc and most importantly explains exactly what parts can be changed to customize or enhance the performance where desired. You rarely find a project write up this comprehensive.What did you expect to get then? A forum member to also source you the parts and assemble it for you?

author: nali
author_rank: Frequent Contributor
timestamp: January 11, 2021, 01:24:38 pm
content: Quote from: m3vuv on January 11, 2021, 11:22:50 amThen take a at the EEZ series from @Prasimix (from this forum) which meets your requirements, being fully open source and evenArduino based - so you can tweak away to your heart's content.

author: Zero999
author_rank: Super Contributor
timestamp: January 11, 2021, 07:53:42 pm
content: Quote from: m3vuv on January 11, 2021, 12:20:25 pmNo one can help you, unless you're more specific. If that project is unsuitable, then why? Perhaps you should learn how it works and customise it. No one is going to do it all for you.Quote from: Berni on January 11, 2021, 11:40:28 amIt looks like a good project. There are a couple of things which I'd add. 1: a fuse is mandatory and 2: some form of over-voltage protection, so it doesn't blow your circuit up, if the MCU crashes, (hopefully it's set up with the watchdog timer to turn the output off, if the code crashes), or the output transistor fails short circuit. If software control is important, the over-voltage protection could be another MCU, in addition to the usual SCR crowbar. Either way, it should be another chip, not the same MCU as the main control loop.

author: m3vuv
author_rank: Super Contributor
timestamp: January 11, 2021, 07:57:43 pm
content: well said that man

author: ledtester
author_rank: Super Contributor
timestamp: January 11, 2021, 09:11:33 pm
content: Some other forum threads about that project:-https://www.eevblog.com/forum/beginners/hiland-power-supply-kit-voltage-spike/msg1557505/#msg1557505-https://www.eevblog.com/forum/projects/arduino-controlled-power-supply/msg333219/#msg333219-https://www.eevblog.com/forum/chat/software-for-dave_s-power-supply/msg92430/#msg92430The links for the original undergraduate thesis project mentioned in the first post of that thread have moved to:-https://soygul.com/uC-power-supply/-https://soygul.com/uC-power-supply/Diploma_Thesis.pdf(NB: in Turkish)And here's a video (not the best) of some scope traces under load:https://youtu.be/tET7Sh0r6vA