Digimess HV30001 repair - 300V 1A bench DC power supply

[tom66]

Re: Digimess HV30001 repair - 300V 1A bench DC power supply

JST-VL series connectors.
20A 600v

I'm talking about connectors you can easily screw in or use test leads with.

[stj]

Re: Digimess HV30001 repair - 300V 1A bench DC power supply

4mm shrouded jacks - like on meters?

some of those are rated 1000v and upto 32A
http://www.rapidonline.com/4mm-single-pole-connectors

[tom66]

Re: Digimess HV30001 repair - 300V 1A bench DC power supply

It's pretty difficult to find ones that will allow wires to be mated to easily. Anyway, this is a project that will be done after 50 others on the list.

What I really want is something like this unit with these kinds of jacks on it:
http://www.ebay.co.uk/itm/Electronic...AAAOSwF1dURMd2

[stj]

Re: Digimess HV30001 repair - 300V 1A bench DC power supply

insulated binding posts?

http://www.rapidonline.com/rvfm-4mm-30a-terminals-63907

[tom66]

Re: Digimess HV30001 repair - 300V 1A bench DC power supply

insulated binding posts?

http://www.rapidonline.com/rvfm-4mm-30a-terminals-63907

You'll find those are typically not rated to 300VDC, more likely something around 60VDC. They'll handle it fine for most cases, but you don't want the exposed conductors anyway when you're dealing with anything around that kind of range. This comes down to insulation ratings in the plastic and the design with the exposed conductors which electronic loads don't generally have.

The other issue - is handling both extremes of high voltage and high current. You can get 400V rated MOSFETs cheap, but on resistance is pretty bad - like 0.1 ohms is the minimum for anything cheaper than "silly price". And if you want say 30A full load current, you're going to get a load of voltage drop across just one FET. So you need many in parallel. And this increases gate capacitance and control loop design complexity considerably.

[stj]

Re: Digimess HV30001 repair - 300V 1A bench DC power supply

those are shrouded and rated for 250v

[Behemot]

Re: Digimess HV30001 repair - 300V 1A bench DC power supply

I pulled the bulk mains caps which are rated at 1000uF 200V a piece while replacing the transistors on the heatsink. To little surprise they test considerably below rating at 850uF each, so they are probably 820uF caps.

That's still within +-20 %. Most even new large-can caps I've ever measured with ESR Micro or UNI-T UT210E always showed lower capacity. No reason to call them fake right away. Usually only Rubycon caps measure close to full.