30 volt, 10 amp power supplies value - Page 1
Forum section: electronics / general

author: MrAl
author_rank: Super Contributor
timestamp: April 29, 2023, 02:03:36 pm
content: Hi there,I have these 30v 10a power supplies. They are quality units with built in meters and course and fine adjustments for the voltage and current (four pots altogether). I think i paid $150.00 USD each for these units and only used them a few times.They are switchers and have a linear back end, so they are both switchers to keep the power losses down and linear to keep the output smooth like a linear supply. I think the part number is HY3010 or something like that. I did buy them about 10 years ago, but havent used them much as mentioned.What do you think these are worth, considering they are used but only used maybe 10 times or so. I also have a full schematic for them.

author: Brumby
author_rank: Unknown
timestamp: April 30, 2023, 03:51:13 am
content: Assuming they are fully functional, then they would certainly be of interest to others, but their value will vary with the cost of shipping. While not a full-on boat anchor, they aren't light. It's the bottom line that will be used in assessing how much an interested party will part with. Local pickup will have the best economic appeal, but will severely limit the market.While I am not familiar with how well they function, from your description I would certainly consider them a desirable item and not something to throw away.What price to put on them? That I couldn't say, but you might get an idea by looking on eBay. If you do, don't pay any attention to the prices on units up for sale - look at the prices for units that haveactually been sold(Completed listings).

author: MrAl
author_rank: Super Contributor
timestamp: April 30, 2023, 01:32:50 pm
content: Quote from: Brumby on April 30, 2023, 03:51:13 amHi,Yes that's an interesting idea.I'll have to find out what it would cost to ship them.A drawback is that there are switchers being sold for under $60 now so people might be drawn to that. Those units do not contain both a switcher and a linear in one package though, just a switcher.Both of these are fully functional with brand new quality potentiometers and one was modified to have an extra input protection against reverse voltage connections to the output terminals, although they both had some protection when new also.

author: coromonadalix
author_rank: Super Contributor
timestamp: April 30, 2023, 01:48:13 pm
content: even modified or enhanced, for me they loose value since thay have been tampered, even if done correctly and professionally, it means opened ....my 2 centsand pls put your location in your avatar ...

author: edavid
author_rank: Super Contributor
timestamp: April 30, 2023, 02:43:55 pm
content: The problem you are going to face is that there are many generic power supplies of this description available for $50-60 delivered on Amazon and eBay.Example chosen at random:https://www.amazon.com/dp/B0BN1GZP9JThe ones you have may be higher quality, but that's hard to quantify. Also, they are used and have no warranty.I have trouble seeing how you can get more than $50 each for them.

author: MrAl
author_rank: Super Contributor
timestamp: May 03, 2023, 02:02:48 pm
content: Quote from: coromonadalix on April 30, 2023, 01:48:13 pmHi,That's a good point. Yes i worked in the power supply industry so i know what works and what doesnt, but i'd have to explain that to i guess.Good idea about the location too, i didnt realize that i did not include that i usually do. New Jersey.

author: MrAl
author_rank: Super Contributor
timestamp: May 03, 2023, 02:10:08 pm
content: Quote from: edavid on April 30, 2023, 02:43:55 pmHello,Yes i think you are right and i was thinking that too. The generic ones are cheap. They do not include a linear section like these do, but the importance of that is hard to convey also. A controlled linear output combined with a switcher means high efficiency combined with the smoothness of a linear, but who is really going to need that except for a professional test set.This is also a little funny because i bought a cheapy myself just a week ago. It's about one-sixth the size of the switcher/linear ones, although it only goes up to 5 amps not 10 amps, but i think they have 10 amp models too that are much smaller now.There is a difference though, the bigger ones have a better adjustment quality that allows adjusting the output more accurately. The smaller one has much smaller knobs and it's hard to adjust to a specific value within about 20mv. Still, it's nice and small and very useful i already used it for some testing. I paid $44 plus tax for it, while the bigger ones were much more expensive.I hate to say it, but it's almost like i have to recommend that someone buy one of the smaller units (ha ha) and only the bigger units if they need high efficiency combined with a smooth output and better tiny voltage adjustment, and i dont think that would reach a very large audience. I think most of us would be happy with the smaller, lower cost units.Yes $50 would be it i bet.Thanks for the reply.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: May 15, 2023, 11:46:56 pm
content: You might offer them on a military radio forum. Military radios operate at 28 volts and some folks are very interested in keeping the spurious signals down so that they do not interfere in their radio's reception.