Inexpensive 3 output power supply - Page 1
Forum section: electronics / testgear

author: Joel_l
author_rank: Frequent Contributor
timestamp: October 01, 2017, 03:01:54 am
content: I have an older model Mastek HY3005-3. It's a linear supply, works OK after adding some caps to the outputs. The problem I do have with is it is when doing some work on my old RC radios. As soon as the RF goes on, the displays go crazy. The output voltage stays stable and set but I have to turn the RF off to make any changes and see what it's doing without using a separate meter.I do like the 5A output but would like something that is going to work well when near RF. The RF is not strong 1/8W 53MHz and 72MHz. It does not seem to have an issue with 2.4GHz.Not looking for high dollar stuff, maybe @ $350.00 or so. Looked at the Rigol and Siglent stuff but they are around 3AsAny thoughts? I see there is a new version of the HY3005-3 but don't know if it is improved in any way from my old one ( the displays are different ).Thanks

author: tautech
author_rank: Super Contributor
timestamp: October 01, 2017, 03:18:56 am
content: Quote from: Joel_l on October 01, 2017, 03:01:54 am6A if you put them in parallel mode or 60V in series mode. (loose one channel)

author: Joel_l
author_rank: Frequent Contributor
timestamp: October 01, 2017, 01:51:25 pm
content: I do that now with the Mastek to get 10A. Not very often but 10A is handy when I need it.

author: Jeroen3
author_rank: Super Contributor
timestamp: October 01, 2017, 02:26:13 pm
content: Quote from: Joel_l on October 01, 2017, 03:01:54 amDid you test if this was conducted or emitted noise? Becuase to me this is a sign you need a better power supply filter in your product.

author: DaJMasta
author_rank: Super Contributor
timestamp: October 01, 2017, 02:56:27 pm
content: Quote from: Joel_l on October 01, 2017, 01:51:25 pmMaybe a combination of power supplies is better then? It's more difficult to find a 10A supply that has any higher voltage range because of the watts that can burn, but it's not too hard to find single channel supplies that do this or more. While it's probably not as cheap of an option, you could get a triple output for wider voltage range and logic/analog signal level stuff and then get a second single channel unit for high power usage. If you want 10A and more than one output.... they certainly exist, but probably not in that price range.+1 to filtering that output. If your RC radio, for example, is designed to run off a battery, they don't care about any of the potential noise generated into the power supply and probably didn't design anything to protect against that, but if you're powering it from a power supply, you certainly may care about it then. I'd get a decent sized inductor/common mode choke to put inline, or at least some ferrites for the power supply leads, as a starting point for cutting down on the unwanted emissions.

author: Joel_l
author_rank: Frequent Contributor
timestamp: October 01, 2017, 04:58:16 pm
content: The issue is when I'm powering the radios I'm working on from the P/S, conducted noise certainly likely the issue. Easy enough ( and a cheap fix if it's it ). I'll make a filtered power lead and give that a try first.

author: shteii01
author_rank: Frequent Contributor
timestamp: October 02, 2017, 01:17:15 am
content: can you put a steel plate (pc case side cover) between rf source and psu?

author: Joel_l
author_rank: Frequent Contributor
timestamp: October 02, 2017, 01:05:08 pm
content: Unfortunately that won't help. The PSU is already all metal and I believe the problem is conducted not radiated.