Inexpensive PSU recommendation?

Hi everyone!

Would anyone have a recommendation for a relatively inexpensive, but high power PSU?

I’d like to get at least 24V, but even better if it could do up to 40V, and really quite high power, so I could test up to 30 or 40A…

I’d like to find a power supply I can just run safely off the mains, since I don’t like the idea of hobby LiIon or LiPo packs lying around my desk. That sounds like a good way to burn down my house, or am I being too cautious?

@runger

Do you perhaps know what is the price range you are looking for? That would help a lot.

Generally, anything over 24V/30A continuous also requires you run a separate power line from your circuit breaker. You are a little bit running into a dangerous territory.

Cheers,
Valentine

Hi

Most of my PSUs are Meanwell directly from china.

Cheers

Nah, over here our mains is 230V and its no problem to run a 1200W device, that’s like a microwave, electric kettle or a power drill. And in my basement here I have a bunch of separate circuits for my power tools, including some high power 3-phase ones, I’m good in that department.

Plus, the 30A would hardly be continuous, just as a max for short term tests.

Well, really as cheap as possible while still being safe…

I would look into getting something used from ebay. Definitely brand name like Siemens, ABB, HP/Agilent, TDK, etc. Avoid Chinese as at all cost. Listen to me. I used to service high-end scientific lab equipment.

Proper power supplies like that cost a lot of money, I mean $2000+ , you already know that. Best you could do is find a high quality used one from labs that sell used equipment.

Hers is an example from EBay:

Good luck.

Cheers,
Valentine

Thank you for those tips, I guess I’ll check eBay :grimacing: I’ve been avoiding it lately due to all the scams, but perhaps I have to take the risk.

In terms of the cheaper Chinese models, I guess I’m with you in terms of what I’ve found so far. The Amazon reviews for the high power models I’ve found have been pretty condemning, not exactly giving you the confidence to buy.
But I’m not sure I’d completely preclude something useful coming from over there… I think if you find the right one there could be some high quality products from China too, why not?

I fear a lab supply of that level is beyond my budget if I don’t find it on eBay. I was just wondering if there is some common technology out there that uses 24V or 40V - like LED lighting, battery charging or power tools of some kind - something where mass production has produced something cheaper that I could repurpose…

Anyway, once I’ve found something I’ll post it here :slight_smile:

EBay has many problems. However, for very specialized equipment, I’ve never had problems. The key is to contact the seller before you buy the equipment and ask simple questions, and make sure the seller responds.

Another way of acquiring high quality and very cheap equipment is lab auctions. Don’t know about where you live but here in SV we have specialized auctions, you can go and bid for really cheap lab equipment from companies that either go out of business, downsize, or upgrade and need to unload all the existing lab equipment. It sounds really strange but once I got a working DNA sequencer from Hewlett Packard for $200, and ran this in my garage to sequence my DNA. That was a really crazy and stupid idea. Another time I bought a really cheap broken lab instrument that had a lot of platinum wiring inside, and no-one knew that, I knew because I used to work on this equipment, so I pulled the platinum and sold it for $$$. Good times.

Find any lab auctions around where you live if possible. Europe is great, you can catch a train to anywhere.

BK (B&K Precision) is a California company. This is something you may consider. Located in Yorba Linda so you get a refurbished box directly from the manufacturer.

https://www.bkprecision.com/about-us.html

I have one of these at work:
CPS-6017

They are all over aliexpress in different versions: aliexpress

We have the 60V, 17 Amp version.

I have been pulling 600W continuous for days at the time.

The display/controls could be easier to use, but it’s fine if you don’t change settings often.

We run LIPO batteries in parallel to soak up excess power generated by the motor controller when slowing down the motor.

Hoby lipo batteries can be safe. Just follow some rules…

  1. All the batteries are contained in a fireproof metal container, like an old military surplus ammo can. These will safly contain anything the battery can do.
  2. place a fuse INSIDE the box with the battery so any wire that comes out of the box is use at less then the ampancy of the wire.
  3. a shutoff switch is mounted to the box with its terminals inside the box and handle outside.
  4. the battery inside is physically held down with velcro srips

So you have to open the top of the box to charge the battery but you can place the whole setup outdoors if you like. Then close the lid and brig it inside.

If you don’t like lipo, then buy a set of 12 volt marine batteries and wire then in series for 24 or 36 volts. But the above rules sould still apply, blace them in a battery bt with a fuse and switch.