DIY Bench Power Supply Question

Hachune · 02-21-2023, 02:27 PM

Hi,
I really need a bench power supply for finding shorts. I am a hobbyist and never had one before, I still plan to buy one in the future but will this setup work for the time being?

1. ATX PSU - I have multiple of them lying around (albeit old stuff), I believe they can provide pretty high amps on 12v rail.
2. Buck converter with variable voltage and amp control with a volt/amp meter. Link to the product : https://robu.in/product/5a-cnc-dc-dc...supply-module/
3. A multimeter probe at the output.

I plan to desolder all other voltage wires except +12v, a ground wire and PSON (green wire). But I have no idea if it will work as intended. I have no other plans of usage except for finding shorts in a mostly a PC motherboard and graphics card.

Please help me out. Thanks.

**harp** · 02-23-2023, 06:46 PM

The ATX PSU for most short finding is overkill.
I use the common small wall adapter 12v/1A with similar module setup, current limit, v addjust and display...

But, it nice to have proper linear bench psu

BTW, what is your prefered plan/method to find shorts component?

**sam_sam_sam** · 02-23-2023, 08:26 PM

My preference is to use the 3.3 volt rail and maybe the 5 volt rail and use a lm317 in the current mode you could even use the 12 volt rail but only after you determine whether or not you actually have a short

But if go with a lm317 regular in the current mode please use a good size heat sink for this application

Or you use something like a buck converter for this

https://www.ebay.com/itm/224143044400

If use this type of buck converter please make sure that you can turn the current all way down to about 50 milliamperes or so “0” milliamperes some of these boards are not going to work properly

Case in point I bought 5 of them and one of them the current section did not work correctly but the meter section did it was a good thing that I had bought 5 more of them but without the meter

If you decide to go with this idea do yourself a favor and replace the pot controls with something that can stand to be moved up and down repeatedly because the pot controls that are on there are not meant to be used that way

02-23-2023, 06:46 PM	#2
harp Badcaps Veteran Join Date: Jun 2022 City & State: 45.2,14.4 My Country: Planet Earth Posts: 210	Re: DIY Bench Power Supply Question The ATX PSU for most short finding is overkill. I use the common small wall adapter 12v/1A with similar module setup, current limit, v addjust and display... But, it nice to have proper linear bench psu BTW, what is your prefered plan/method to find shorts component? Last edited by harp; 02-23-2023 at 06:49 PM..

02-23-2023, 08:26 PM	#3
sam_sam_sam Badcaps Veteran Join Date: Jul 2011 City & State: Some times Sunny Jacksonville FL My Country: USA Line Voltage: 120 Volts 60 HZ I'm a: Knowledge Seeker Posts: 4,300	Re: DIY Bench Power Supply Question My preference is to use the 3.3 volt rail and maybe the 5 volt rail and use a lm317 in the current mode you could even use the 12 volt rail but only after you determine whether or not you actually have a short But if go with a lm317 regular in the current mode please use a good size heat sink for this application Or you use something like a buck converter for this https://www.ebay.com/itm/224143044400 If use this type of buck converter please make sure that you can turn the current all way down to about 50 milliamperes or so “0” milliamperes some of these boards are not going to work properly Case in point I bought 5 of them and one of them the current section did not work correctly but the meter section did it was a good thing that I had bought 5 more of them but without the meter If you decide to go with this idea do yourself a favor and replace the pot controls with something that can stand to be moved up and down repeatedly because the pot controls that are on there are not meant to be used that way __________________ 9 PC LCD Monitor 6 LCD Flat Screen TV 30 Desk Top Switching Power Supply 10 Battery Charger Switching Power Supply for Power Tool 6 18v Lithium Battery Power Boards for Tool Battery Packs 1 XBox 360 Switching Power Supply and M Board 25 Servo Drives 220/460 3 Phase 6 De-soldering Station Switching Power Supply 1 Power Supply 1 Dell Mother Board 15 Computer Power Supply 1 HP Printer Supply & Control Board * lighting finished it * These two repairs where found with a ESR meter...> Temp at 50F then at 90F the ESR reading more than 10% 1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later ) 2 Hem Saw Computer Stack Board All of these had CAPs POOF All of the mosfet that are taken out by bad caps Last edited by sam_sam_sam; 02-23-2023 at 08:35 PM..

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode