Thurlby Thandar TS3022S dual power supply teardown - Page 1
Forum section: electronics / testgear

author: bd139
author_rank: Super Contributor
timestamp: August 02, 2017, 04:34:28 pm
content: First tear down of many from me. I'll go through all my kit over the next few months!My old power supply decided to blow the filter cap out a few days ago on the 5v output so I decided to buy a new one. The old supply's filter cap was dated 1977 so I suppose that's good mileage for an electrolytic cap. I have repaired this but I don't want it any more as TBH it's ancient and has analogue metering. After some deep humming and hawing over some new Keysight U8001's and some older HP E3610's listed I decided I'm a cheap arse plus I want some money left over for a new scope, so a quick scan of ebay found a working Thandar TS3022S for just under £100 so I grabbed it. I've got a PL310 as well but I need 3 power supplies a lot of the time and the old one was a dual unit.Arrived poorly packaged with a damaged binding post and completely munted plug. I've never seen anyone kill a UK mains plug. However the kind seller refunded £25 which is a. Obtained and replaced the plug and ordered a new binding post and we're in business. So 2x 30V 2A independent supplies with digital metering and current limit for £75. No horrible fans like the cheap Korad things either! I'm happy.How the hell?Calibration isn't far off. I compared it to a (properly calibrated) Fluke 8600A and it's about 200mV out at full scale on both sides. Current is spot on. Only one dicky things with it: current limit can be set past the 2A limit but the display shows only "1." after that when in set mode. I will see if this is a calibration thing later when I recalibrate it.Nicely built as all recent Thandar stuff seems to be. The very old brown PL supplies are shit. My PL310 is a relatively recent one thank goodness!No sign of drift which is a common problem with these. Seems to be 2001 vintage. There are no custom ICs in these. They are just a couple of opamps, a load of 4000 series logic and a couple of ICL7106 DVM ICs. Technically speaking that makes them repairable into the far future.Money shot - two independent supplies in the box:2N3055 pass transistors on proper heatsinks means no fan!Nice construction. All modular connectors:Quick check:Service manual is available with some Googling. PM me if you want a copy. I will email you as it's too large to stick on the forum as an attachment.

author: alm
author_rank: Super Contributor
timestamp: August 03, 2017, 01:13:50 am
content: Quote from: bd139 on August 02, 2017, 04:34:28 pmHow about uploading it toKO4BBandTiN's siteso it is available for everyone?

author: BravoV
author_rank: Super Contributor
timestamp: August 03, 2017, 03:08:31 am
content: Internally looks similar or even identical to my PL330QMD -> (Brief Internal Shots)Curious what brand of caps it uses ? Mine all are Capxon (->Link).

author: bd139
author_rank: Super Contributor
timestamp: August 03, 2017, 06:49:31 am
content: Quote from: alm on August 03, 2017, 01:13:50 amGood plan. Will do that.

author: bd139
author_rank: Super Contributor
timestamp: August 03, 2017, 06:52:53 am
content: Quote from: BravoV on August 03, 2017, 03:08:31 amThese are all Elna ones. They may get replaced shortly with Rubycon low ESR units.

author: Vtile
author_rank: Super Contributor
timestamp: August 03, 2017, 09:40:35 am
content: One note is that the 3 output units TS3023S do have 2 same linear modules 30V/2A, but the third one isn't linear, but a SMPS and the manual doesn't particularly clearly state which is the used topology. Also the ICL DVM chips might leak some ~6½kHz/26.9kHz ringing to outputs. Other than that I like these.

author: bd139
author_rank: Super Contributor
timestamp: August 03, 2017, 10:27:32 am
content: Yeah I saw a comment related to the triple output ones. This is all linearI have a new scope arriving tomorrow with 1mV/div sensitivity so I'll stick a load on and see if there is any noise from the DVM ICs. That should be relatively easy to mod to get rid of though. Thanks for the heads up.

author: Vtile
author_rank: Super Contributor
timestamp: August 03, 2017, 02:08:40 pm
content: I also though I mention that if someone gets these units from the ebay, the distribution line voltage adjustment is made with hardwiring the transformer tabs. No selection switches on these, correct settings are found from service manual.

author: alm
author_rank: Super Contributor
timestamp: August 03, 2017, 02:33:17 pm
content: It is good to know that they are switchable. Some old power supplies require a transformer replacement:

author: bd139
author_rank: Super Contributor
timestamp: August 05, 2017, 08:47:24 am
content: Yeah I actually had my eye on an E3610 until I found that out!Well I did some measurements on the unit and there was a lot of regular digital noise on it. After an hour of head scratching I found out that (a) my scope is actually on 1mV mode on 10x which made this much worse than it looked and (b) what noise out there was is leaking through from the switch mode on my work lamp. Now there's nothing discernible from background. At full load (in a small cloud of resistor smoke) there's about 2-3mV of ripple on each channel which isn't too bad at all.£75 well spent

author: vmiceli
author_rank: Newbie
timestamp: September 22, 2019, 10:44:18 am
content: Folks, any chance of a fresh link to the service manual of a TS series? All I can find is the S series, but I was going to calibrate a TS3021S and the trim pots are on a totally different layout than that of an "S" series...Thanks!!Enzo

author: bd139
author_rank: Super Contributor
timestamp: September 22, 2019, 10:53:03 am
content: Unfortunately I got rid of that supply ages and and don’t have the SM. If you contact Aim-TTi they will send you a service manual usually. They’re good like that.

author: vmiceli
author_rank: Newbie
timestamp: September 25, 2019, 09:04:32 pm
content: I got in touch with the manufacturer and the service manual for the TS3021S is indeed the commonly available "S" series. I was put off by that manual because the trimpot layout on pg.11 didn't match my unit. However what matters is the name of those trimpots not where they are located on the PCB. So I did the calibration and it worked very well.V.

author: bd139
author_rank: Super Contributor
timestamp: September 26, 2019, 06:23:40 am
content: Good to hear. I think I had the same problem when I had mine with the trimpot location.