DIY Low Voltage / Very High Current Power Supply for Benching High Current Amps - Page 1
Forum section: electronics / projects

author: Tekjive
author_rank: Contributor
timestamp: January 28, 2022, 04:02:34 am
content: Hey all, this is my first real post, besides a WTB I didn’t end up needing 😅 a new friend suggested this site and wow what a wealth of knowledge I can’t wait to dive into! As far as me just a quick hello I guess, I’ve been into PC and car audio since teenage years, got a few degreees in PC networking (figured it was a stable career choice) also am a “certified” electrical apprentice, etc. I rebuild/mod subwoofers, build high watercooled gaming PCs, I also model/mod WarHammer40k, so I’m pretty good with my hands and figuring stuff out. my fiancé says I need a pair of specs that have multiple lenses like a steampunk scientist, lol.Recently I’ve gotten into Car Audio Class D Amp repair, been building up my test equipment, etc, but seems there’s no low voltage / high current power supplies (that aren’t expensive af industrial types) and was wondering if there was any DIY already done, I tried searching a few times for keywords and it’s usually the sub 50amp stuff discussed, what I thinking of is something along the lines of 0-24v (but will usually be run in the 12-16v range) with high current capabilities so I can really bench an amps performance. Some amps will burst up to 500+ amps and even more. Right now I have a 100amp Server Power Supply modded up to some 12v batteries for the burst, I was thinking of just expanding on this for now but eventually I’d like to build an adjustable PS that can handle bursts of 500+ amps. Is it just better to run/expand on what I have currently? I’m new to stuff like this but reading/learning as much as I can so I can do it properly, safety is #1. The amount of research done before even modding my server PSU was borderline OCD, lol, I’m not trying to blow anything up 😅 also as a side inquiry how would one run multiple 100amp server PSUs in order to combine their current/amp output, connected in parallel with my 12v car batteries for bursts? I’d like to run 3x/100 for a “reliable” 300 amps of power without having to dig into the batteries supply, does that even matter tho?Like I said I’m still learning the ins and outs of everything with power supplies, etc and want to do it right, if I even do it, and or make sure what I’m doing now is safe as well, maybe I should go the huge battery bank most do when they bench/dyno amplifiers? Any and all insight/info/etc much appreciated, really looking forward to exploring the site and being part of the communityRichEdit: I’m seeing more and more posts similar to this, without the “meet and greet” and I’m sure all the OGs&Pros are getting tired of them, I apologize if this topic had been beaten to death, thinking I should just go with the battery bank most do instead of trying to reinvent the wheel ...maybe there isn’t consumer grade PS like this for a reason ...so ya don’t know how long this post will even stay up 😅

author: bdunham7
author_rank: Super Contributor
timestamp: January 28, 2022, 05:04:04 am
content: How long are the 'bursts' of 500 amps? The problem is that if you don't use some form of storage--supercaps or batteries--you will need a much larger input than standard wall socket. At 120V primary, you need at least 50 amps input to get 500 amps out at 12V--and in practice you typically need quite a bit more than that. A while back I looked at a bunch of high-current supplies on that order, although I don't remember any details. Those used 480V 3-Phase inputs. You could possibly get by with single phase 240V, but I don't know of any products that are suitable. You're talking about power levels on the order of home-charging an EV. The only thing I can think of that might work is to find a 240V SMPS that can be adjusted for voltage and is OK being run in parallel--and then get as many as needed.

author: inse
author_rank: Super Contributor
timestamp: January 28, 2022, 05:33:33 am
content: I absolutely agree to the first reply.As I can hardly imagine exposing myself to 6kW of electrical power converted to acoustic power for extended (if any) period of time, a battery would definitely be the go-to solution.Furthermore, 500A results in a mere plumber work.If you want to do an electronic improvement of your BBPS, think of an electronic fuse (not current limiter) with a bunch of paralleled MOSFETS mounted on appropriate busbars.This could save money for expensive high current fuses.

author: NiHaoMike
author_rank: Super Contributor
timestamp: January 29, 2022, 02:08:46 am
content: A few "SPIM08HP" battery modules are hard to beat for value. 4 in series will get you the voltage you're looking for and will give you 400A for about 2 minutes or 800A for 3 seconds.https://batteryhookup.com/products/2x-spim08hp-3-7v-8ah-cells-with-threaded-insertThat said, I would expect extreme car audio to migrate over to the 400V or so batteries used in EVs, the lower currents are much easier to manage.

author: Faringdon
author_rank: Super Contributor
timestamp: January 30, 2022, 01:39:56 am
content: Hi,You can get high current out of vicor modules if you want.Yes the sub-woofers need the higher power as the low frequency means it cant just come out of a capacitor bank unless its huge.What about getting a system that can work on a higher voltage, then you can reduce your current.But for high current in general. you can parallel power supplies as in the following SMPS course....https://drive.google.com/file/d/17ij_pQLkAzzYeL_TRNci86sXHMirKHmD/view?usp=sharinghttps://drive.google.com/file/d/1WvElhDNfHI0EBei4rouSNEdWWTO1oCtJ/view?usp=sharingFolder is called"Low Vout high current SMPS"Also..."Parallel SMPS's"..sorry i cant remember which of the above two they are in.I think the best way to do pllel SMPS's , is just to parallel voltage output smps's, then add a current clamp to the output of each one so that none can go over nominal maximum currrent...then they all share equally at max load, which is what matters most. Alternatively You can do the old "share bus" method of paralleling, but that has a slow bandwidth, and if your bursts happen suddenly, then thats no good to you.You can pllel vicor modules directly, by picking the "array" ones...or just use the other ones and add the current clamp to the output of each as discussed.....its easy to do, just add an opamp and current sensor...and pull the TRIM pin down so it current clamps.Hall sensors are good for reading high currents.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: January 30, 2022, 02:12:43 am
content: Well, for no cost at all you can study the Tektronix High Current Adapter for their curve tracer.https://w140.com/tekwiki/wiki/176It may not delight you with only 200 amps, and in any case they are are rare, but the circuit description is fun to read.

author: Tekjive
author_rank: Contributor
timestamp: January 30, 2022, 05:35:38 am
content: Wow, the information in all of the replies is amazing, and such an eye opener on some aspects of the setup I had in mind that I didn’t even consider. Just wow, first off thank you everyone, I know this appreciation may seem a little odd for just answering some questions, you’ve all been so receptive and helpful, it’s just some some forums I belong to aren’t and I can’t tell you how refreshing it is to read replies that are not negative in any way, but seek to inform and give different ideas on how to achieve the intended goal, I really do appreciate that so much. 🖖🏼As far as the info in the replies, I’m going to dig in deep on each as this is something I really want/need for my bench (that ever burning dilemma right, want vs need lol) and I’m excited to see the different options Ive never even thought of or knew existed. As for the benching/dyno part of the setup it wouldn’t pull that high of current for longer then a “burp”, which is a sustained frequency @ max unclipped/just clipping volume for about 3-5 seconds, usually in the 40-60Hz range. I don’t currently have the ability to mod my electrical (although I’m sure my landlord wouldn’t mind lol) as I’m renting atm but when I do finally have my own place fairly soon I’m going to make sure I can handle just about anything, and some of these amps can put out 17Kw+ RMS 🦾🤓🔊 I’m mainly into Korean Half Bridge Class D designs.I’m still learning amplifier repair and electronics in general (just got my proper scope today actually, Hantek DSO2C10) but I’m really glad I was referred to this site and so early on, I can tell I’m going to learn a lot, and hopefully contribute a lot as well, thanks again for all the great replies/information/great attitudes, like I said it’s so refreshing to be able to converse on what some may deem “unpractical” in a positive way, man I’m just blown away guys lol 😅 thank you!Rich