Is my power supply okay? - Page 1
Forum section: electronics / repair

author: Muffins
author_rank: Regular Contributor
timestamp: October 09, 2024, 08:32:55 pm
content: I just bought a power supply off of Ebay, it's a linear one from RS. This one:https://uk.rs-online.com/web/p/bench-power-supplies/1757367?srsltid=AfmBOooTPqgRXlLzwrGbxjqXV4c1zNDLIn2LEZK_EJlZGOcvb4GtTIG0Now, the seller failed to mention that the power supply had been dropped and the pics hid this fact. Something hit the side of it enough to put a deep dent in the sheet metal on its side and the inertia of the transformer being jolted also bent the bottom panel a little.The machine does work though, it outputs the correct voltages. The problem is when there is a current more than say half an amp the transformer buzzes at the supply frequency. Seems to still work fine at 2.5A and I haven't taken it passed that yet.Do you think I should return it or should I have a go at fixing this? It was half the new price.

author: thm_w
author_rank: Super Contributor
timestamp: October 09, 2024, 09:08:17 pm
content: Crank it to 5A and let it run for a while. Maybe tighten those screws you can see on the bottom see if that affects the buzzing at all.Sure the damage didn't happen when shipping to you?

author: PlainName
author_rank: Super Contributor
timestamp: October 09, 2024, 09:37:37 pm
content: QuoteIf you're asking then you don't know if you can fix it, and once you try you can't send it back. Thus the logical thing would be to start the return process.You could contact the vendor and tell them that you intend to return it, and why, and suggest and alternative in that you keep it and then give a partial refund (the amount to be negotiated between you). But be aware that going that route would make them suspicious that you're trying to pull a fast one, so a straight return is probably wiser.

author: Muffins
author_rank: Regular Contributor
timestamp: October 10, 2024, 11:19:38 am
content: Okay, thinking on this I've requested a refund rather. Probably the better decision.Now to look for another bench power supply.

author: PlainName
author_rank: Super Contributor
timestamp: October 10, 2024, 09:46:46 pm
content: Do you have particular requirements? I might have something suitable, and this seems like a decent excuse to regain some shelf space

author: Muffins
author_rank: Regular Contributor
timestamp: October 11, 2024, 08:29:01 am
content: Well I would like a decent linear power supply, with two outputs would be great. What might you have available?

author: PlainName
author_rank: Super Contributor
timestamp: October 11, 2024, 08:45:27 am
content: I meant in the way of minimum voltage and/or current.Also, whereabouts are you located? Shipping for linear supplies can be a drag, so a possible collect or drop off could make the difference.Only single output but would this be suitable:https://uk.farnell.com/tenma/72-10480/power-supply-1ch-30v-3a-adjustable/dp/2251946It's a badged Korad KA3005 (or vice versa) and schematics are apparently available on t'web.

author: Muffins
author_rank: Regular Contributor
timestamp: October 14, 2024, 08:41:42 am
content: Thanks for the offer buddy. I'm in the uk but I think I'll bite the bullet and get a new supply. Maybe something more expensive.