Kepco PSU help needed - Page 1
Forum section: electronics / repair

author: JKKDev
author_rank: Regular Contributor
timestamp: March 07, 2020, 03:15:35 pm
content: Hey guys,not too long ago I've acquired a Kepco ATE 15-6M PSU. It's a 0-15V 0-6A !programmable! PSU. It was sold as broken.TLDR: I'm looking for someone with a Kepco PC-12 programming connector (look at the eBay listing below).When I opened it up, pieces of the 10 turn pots were hanging by the wires. No idea if it happened during shipping or what but I got myself some Chinese replacements just for the time being to figure out what's actually wrong with the unit. There were other front panel parts that broke as well (thankfully both voltage and current analog displays are ok). After replacing those as well, I was hopeful, that it would do something. And it did... A constant voltage on the output no matter what.Thinking it's got something to do with the programmable part of the PSU I went digging in the user manual. At this point, I realized my unit is not all there. The PC-12 rear mating/programming connector seems to be required for the operation of the PSU. After looking around this appears to be a simple connector that you solder the jumpers to. However, some schematics made me doubt this as there are some resistors and other components supposedly present.Does anyone own a Kepco PSU with this Programming connector/header that would be willing to help me figure this out? There are jumper configurations in the user manual for different types of operation, however, there is nothing written about the PC-12 itself. Does anyone know what this type of board connector is called (hopefully it's not proprietary) - it seats itself on the edge of the PCB similar to a PCI-E?Hereis an eBay listing of the item (the price is 2x the amount I paid for the PSU so I'm not looking to buy it).Hereis a listing for a similar PSU with a makeshift (I guess) connector installed.Andhereis a list of connections (the two preamps at the top are what's worrying me).EDIT: I didn't see the connector PART NUMBER on one of the eBay listings (future me or anyone else - part number is 345-050-500-204). After looking for that I found the connector itself. Now I just need to know if there's anything other than wires meant to be connected to it.Thank you very much for any kind of informationHave a nice day.

author: duak
author_rank: Super Contributor
timestamp: March 07, 2020, 05:02:25 pm
content: I don't know much about the Kepco power supply control interface.I did find this document on the supply:https://www.kepcopower.com/support/ate-operator-1-quarter-rack-r5.pdfPage 4 shows how the PC12 is connector is wired for local control. Looking closely, you can see that the pins of the connector are wired togther corresponding to the vertical lines to the right of the connector.The picture of the connector makes me think it is something called a "PCB edge connector" These are available in North America in various sizes. I expect Europe to be similar. The problem will be to determine what type. The above document indicates it has 50 contacts. It looks to be about 80 to 120 mm long. is this what you see on the power supply?

author: JKKDev
author_rank: Regular Contributor
timestamp: March 07, 2020, 09:19:56 pm
content: Let's preface this with a fact: I'm not interested in a full restoration of this PSU. It is also never going to be sold or given away as a fully working machine. That being said...It seems the price of the connector (including shipping which is a big part of it) is somewhere in the neighborhood of what I paid for the PSU itself. I am currently not willing to spend that amount of money.After close inspection, I've noticed that the pitch of the contacts on the PCB perfectly matches a 1.5mm pin header. I'm leaning towards soldering two rows of female headers to the PCB and call it good. At that point, I can make either male header permanent configuration plugs or use wire jumpers for custom configuration.Does anyone see anything wrong with this? (except the fact that it will be hanging in the air at the back of the machine instead of having an enclosure)Attached are some photos of the insides.

author: JKKDev
author_rank: Regular Contributor
timestamp: March 07, 2020, 11:14:11 pm
content: I went ahead and did the "mod". It's not as pretty as the original thing but it's working as it should. I haven't tested anything in-depth yet however, I can set the voltage, crowbar, and current. Happy days

author: coromonadalix
author_rank: Super Contributor
timestamp: March 08, 2020, 04:41:16 am
content: I have the kepco ate services manuals, my 3/4 rack ate 75-8m (hefty 50 pound psu ??) was missing this connect tor to make it work, i simply soldered an idc connector (can't recall the pins qty) and done an pc12 equivalent connector, work fine up to this day.I did a few mods in it.I bought 2x 4 1/2 display voltmeters and installed 2x isolated 5vdc psu for the displays, i took the current to voltage output pc12 connector pin (it gives me 2vdc at 8 amps) and adjusted it to the current meter, the voltage meter was added at the same place where the needle meter was connected.Added multi turn pots instead of the originals ...I did a mod to control the fan speed since it was making a very loud noise ... this puppy can dissipate aroud 860 watts of heat pushed to the limits in full short circuit.And finally replaced the main capacitors + 10% more filtering values.

author: JKKDev
author_rank: Regular Contributor
timestamp: March 08, 2020, 06:52:39 am
content: Even this 1/4 rack unit is a heavy chunk of lab equipment so I can only imagine what that must be to even move around on a deskMy little fan isn't too noisy but I guess 100W isn't too hard to dissipate compared to close to 1000W.Any photos of your mods would be greatly appreciated. Now I just need to get accustomed to it

author: JKKDev
author_rank: Regular Contributor
timestamp: March 08, 2020, 10:16:50 am
content: I'm happy to report that even at roughly 1/3 of the rated load (27W LED lamp) it performed well. Setting the crowbar at the max for a car battery (it's a work light) using a DMM (as the gauges aren't displaying proper values - calibrating's going to be a b****) it was consistently turning off as I tried to over-voltage it. Current limiting is also working flawlessly.All in all, for a 45€ PSU (including shipping a 7.5 kg package) I'm happy. The only downside is I'd want to have a few more amps to work with, but you live and you learn.

author: coromonadalix
author_rank: Super Contributor
timestamp: March 08, 2020, 03:55:28 pm
content: Here's a pict, it was sitting on a side lollAnd the meters measurements are pretty spot on, just needed to get the holes bigger by a few mm on each sidesBought for a mere 50$ usd, but 100$ in shipping for its weight lolloh and i paralleled the rears plugs to the front panel too