SOLD (UK) GWInstek PSP405 0-40V 0-5A 200W single channel PSU - Page 1
Forum section: electronics / general

author: TopLoser
author_rank: Unknown
timestamp: September 23, 2017, 02:00:42 pm
content: Customer return, repaired by GWInstek. Boxed, looks like new, all seems to work ok.GWInstek PSP405http://uk.farnell.com/gw-instek/psp-405/power-supply-1ch-40v-5a-adjustable/dp/4911763These are actually nice compact supplies, very friendly little things and with a power display as well as voltage and current. Nice to be able to set a power limit as well as voltage and current limits. Programmable via RS232.List price £288+VAT, whatever. Anybody want to give me £100+shipping (£10 UK, £20 sensible EU countries, elsewhere please ask)?I've also got some PSP603 versions, 0-60V 0-3A for the same price.SOLD

author: Pitrsek
author_rank: Regular Contributor
timestamp: September 23, 2017, 04:06:59 pm
content: One output is not enough for me, by any chance, anything with more outputs in your sleeves?

author: TopLoser
author_rank: Unknown
timestamp: September 23, 2017, 04:18:49 pm
content: Hell yes.... hundreds of supplies 2, 3, 4, 5 ouputs. Voltages up to 600V, currents up to 150A, power up to 3KW.Tell me what you want and what your budget is and I'll tell you what's available.

author: CM800
author_rank: Frequent Contributor
timestamp: September 23, 2017, 04:41:17 pm
content: Quote from: TopLoser on September 23, 2017, 04:18:49 pmI'd be interested in hearing about your 600V power supplies...

author: TopLoser
author_rank: Unknown
timestamp: September 23, 2017, 04:44:53 pm
content: Quote from: CM800 on September 23, 2017, 04:41:17 pmhttp://uk.farnell.com/ea-elektro-automatik/ea-ps-8600-70-3u/power-supply-1ch-600v-70a-adjustable/dp/1830437Got a matching 4.8KW electronic load as well...

author: CM800
author_rank: Frequent Contributor
timestamp: September 23, 2017, 06:44:48 pm
content: I'm almost scared to ask how much you want for that... is it a case, that if I have to ask, can't afford?

author: reddish75
author_rank: Regular Contributor
timestamp: September 23, 2017, 07:15:29 pm
content: Do you have any relatively low power loads circa 10 amps?

author: TopLoser
author_rank: Unknown
timestamp: September 23, 2017, 07:17:49 pm
content: 200A and 400A loads only at the moment, sorry.

author: PA0PBZ
author_rank: Super Contributor
timestamp: September 23, 2017, 07:40:23 pm
content: Quote from: CM800 on September 23, 2017, 06:44:48 pmIf you watched his ads for some time you can tell it's about 50% of the list price, give or take a few.

author: Jon.C
author_rank: Unknown
timestamp: September 24, 2017, 04:30:12 pm
content: @TopLoserinteresting price for this GWInstekyou have some between 3 and 5 amps but with more display resolution ?with 1 output is enoughtype Maynuo M8811 or similar (but cheaper)

author: TopLoser
author_rank: Unknown
timestamp: September 24, 2017, 04:56:53 pm
content: 30V range with 0.1mV steps?No, nothing like that. Nothing cheaper than the Mayuno anyway...

author: CJay
author_rank: Super Contributor
timestamp: September 25, 2017, 09:11:08 am
content: Long shot, I'm either going to build or buy a PSU for ham gear, I would like 13.8V (could be variable if not fixed) at least 25 amps, linear, and cheap as chips, have you got anything?

author: TopLoser
author_rank: Unknown
timestamp: September 25, 2017, 09:19:06 am
content: You can have one of these in unknown condition for £60 shipped....http://uk.farnell.com/digimess/hy3020/power-supply-1ch-30v-20a-adjustable/dp/4283235Be good for parts if it doesn't work, shame it tops out at 25A though.

author: CJay
author_rank: Super Contributor
timestamp: September 25, 2017, 10:51:14 am
content: Quote from: TopLoser on September 25, 2017, 09:19:06 amThat'll certainly give me enough current to run the legal limit for my licence class right now so yes please, I'll send funds and details over when I get home tonight.

author: grumpydoc
author_rank: Super Contributor
timestamp: September 25, 2017, 02:01:58 pm
content: Quote from: CJay on September 25, 2017, 10:51:14 amI would have bought it for repair had you not done so - but then I already have two under the bench awaiting attention.If failed then go straight for the output transistors before anything else - these PSUs really like to blow up one or more of the pass transistors.Teardown & some notes herehttps://www.eevblog.com/forum/testgear/digimess-hy3020-teardownreview/. I have the schematics somewhere if you need.The 2N3055 output transistors are almost certainly outside their thermal envelope at high currents and peak voltage drop (not sure what the drop across the output transistors will be at 13.8V out). I change for 2N3773, MJ15015 is another possibility. I also put a meaty reverse biased diode across the pass transistors as they don't have any protection for voltage applied to the outputs (eg if there is a hefty capacitor somewhere).

author: TopLoser
author_rank: Unknown
timestamp: September 25, 2017, 02:12:43 pm
content: Turned out the ones I had were the even more exciting 50V 20A switching versions... even more potential for explosive failure!http://uk.farnell.com/digimess/sm5020/power-supply-1ch-50v-20a-adjustable/dp/1076812You fancy a couple of these to put under your desk instead of mine?!

author: nctnico
author_rank: Super Contributor
timestamp: September 25, 2017, 02:41:36 pm
content: Quote from: TopLoser on September 23, 2017, 02:00:42 pmI think I want one... Do these have the binding posts or the (awful) recessed banana sockets?

author: TopLoser
author_rank: Unknown
timestamp: September 25, 2017, 02:47:45 pm
content: Quote from: nctnico on September 25, 2017, 02:41:36 pmBinding posts for the 60V ones as well

author: CJay
author_rank: Super Contributor
timestamp: September 25, 2017, 02:52:49 pm
content: Quote from: grumpydoc on September 25, 2017, 02:01:58 pmI'm very interested in the full schematics, even if a faulty one doesn't turn out to be viable as I've got a couple of *massive* toroids that could be pressed into service if necessary.I had a read of that thread too, there's half a sort of schematic in there and I'm nurturing a mad scientist thought that it *may* be possible to parallel those series windings and get even higher current out of what is already a monster of a supply but as yet I don't know what the secondaries are.Definitely needs better diodes and more capacitor though

author: grumpydoc
author_rank: Super Contributor
timestamp: September 25, 2017, 03:01:55 pm
content: Quote from: CJay on September 25, 2017, 02:52:49 pmThe Mastech schematic from the old thread is basically it - don't think there are too many differences but I will see if I can dig out the paper copy and scan it.I think that the secondaries are all different voltages.The diodes seem OK in practice - I did think about using an ideal bridge driver but it would just push heat to the pass transistors, and they don't need the extra strain.

author: TopLoser
author_rank: Unknown
timestamp: September 29, 2017, 10:09:08 pm
content: SOLDAmazed this one took so long, I really like these supplies!