PSU Schematic Suggestions Please Ref: Helena Biosciences EPS 600 power supply - Page 1
Forum section: electronics / general

author: snipersquad100
author_rank: Frequent Contributor
timestamp: October 26, 2020, 06:29:43 pm
content: I bought this Faulty Helena Biosciences EPS 600 power supply on eBay with the intent of fixing it. There was an error displaying on the screen but it was 90% working, the system start boot up check detects something wrong somewhere. But I realised that this can put out a lot of voltage, I believe I saw 345v on the output at some stage. I thought about it for a bit and decided this unit is no use to me as I'd probably end up killing myself, but I liked the design of the case and thought I use the case for a DIY power supply.Upon dismantling I found a nice toroidal transformer with 2 50v outputs (NICE), front bezel with display and buttons, nice common mode choke on the mains input and nice parts on the PCB.What came to my mind was a programmable bench power supply, but I don't know anything about writing code to microcontrollers.So I need to ask if anyone has any schematics on programmable power supplies with the code that would be suitable for this case or if you have any other ideas on what I could do with this case, I love to hear them.Thanks for now.John.

author: snipersquad100
author_rank: Frequent Contributor
timestamp: October 26, 2020, 06:38:25 pm
content: Why can't I send more pics?

author: snipersquad100
author_rank: Frequent Contributor
timestamp: October 26, 2020, 06:43:07 pm
content: Can only upload 5 meg only, gee its 2020.

author: snipersquad100
author_rank: Frequent Contributor
timestamp: October 26, 2020, 06:47:43 pm
content: Any ideas

author: snipersquad100
author_rank: Frequent Contributor
timestamp: October 26, 2020, 06:50:16 pm
content: just the two of us.

author: snipersquad100
author_rank: Frequent Contributor
timestamp: October 26, 2020, 06:53:26 pm
content: just the 1

author: jogri
author_rank: Frequent Contributor
timestamp: October 26, 2020, 06:59:39 pm
content: Quote from: snipersquad100 on October 26, 2020, 06:29:43 pmThat's because this thing is a power supply designed for gel electrophoresis... You apply voltages of up to 3.5 kV to a chamber filled with a gel and some DNA on it and apply a high DC voltage. Molecules of different sizes will drift at different speeds-> you can separate them. Given the fact that it has "600" as a model number i'm willing to bet that it goes to 600V DC and probably 100-250 mA max. Those things are okay-ish as cheap HV power supplies, but don't count on it being extremely accurate.EDIT: Have you checked if you have triggered some kind of safety switch? Those things are HV PSUs designed to be used by people who have no clue about electronics, so they usually have a lot of safety mechanisms to make sure no one electrocutes himself. Here's a list where those switches might be:-at the gel chamber to prevent you from opening it while the PSU is running-at the banana plugs, mine won't even power on if you haven't inserted the cables-something against earth loops-check the timer, they are designed to run a few hours->might stop outputting HV if the timer reaches 00:00

author: snipersquad100
author_rank: Frequent Contributor
timestamp: October 26, 2020, 07:38:52 pm
content: I got no interest in fixing it since I got no need for it, I only paid £25 delivered.I like the design of the case and want to make a bench power supply with it, so the PCB inside is going to be desoldered of most it's parts.

author: snipersquad100
author_rank: Frequent Contributor
timestamp: October 26, 2020, 07:39:57 pm
content: Nice to know what it was used for though.Thanks