I use an extension cord and curl up in a ball in the corner while I plug it into the outlet.

Nice work on the PS's Horio!

I llike to duck under the table with a voltage meter tied to the outputs when I first turn a new build on

EDIT: Just looking at the photos again, I can't tell if you have insulators mounted behind the output fets.

That doesn't sound like a half bad idea.

Regarding the output fets, I have the isolated version of the part (version FQPF8N80C). They are attached to the sinks without an isolation pad, as my understanding was they are already isolated. It would be good to know my assumption is way off here, before I plug it in. I am more of a builder than an electronics wiz.

Edited October 9, 201114 yr by Horio

The bottom ones look like every C3675 I've ever use so they are real.

i agree they look real. if they arent as "clean" they may have been circulating warehouses around the world for a decade or two, or however old the C3675 is

That doesn't sound like a half bad idea.

Regarding the output fets, I have the isolated version of the part (version FQPF8N80C). They are attached to the sinks without an isolation pad, as my understanding was they are already isolated. It would be good to know my assumption is way off here, before I plug it in. I am more of a builder than an electronics wiz.

No thermal interface material either?

I have a giant, thick board of ply that I use as a shield when I test things.

RE: the utsource c3675, I still want to have them tested under a curve tracer though, so if anybody would like to do that, I'll drop a couple in the mail for you.

No thermal interface material either?

Just some thermal paste.

That doesn't sound like a half bad idea.

Regarding the output fets, I have the isolated version of the part (version FQPF8N80C). They are attached to the sinks without an isolation pad, as my understanding was they are already isolated. It would be good to know my assumption is way off here, before I plug it in. I am more of a builder than an electronics wiz.

They are electrically isolated. But you still need some kind of thermal interface.

So either the thermasil silicone impregnated things, or some thermal paste.

Same thing with the 2sc4686a output transistors, and the 2sa1968ls current sources.

the ixtp01n100d are NOT isolated, so they need the aluminum oxide washers.

Nice one Horio, looking forward to hearing the outcome.

Edited October 10, 201114 yr by johnwmclean

Nice one Horio, looking forward to hearing the outcome.

+1

I think I'll order the transformers in the next days to [/url=http://www.toroidy.pl/index.php?option=com_content&view=article&id=6&Itemid=7&lang=en]Toroidy. I asked for a budget of 4 trafos with these specs:

TS 150VA PRI: 2x 115V SEC:

> 1x450v @ 150mA.

> 1x450v @ 150mA.

> 15 - 0 - 15V @ 15VA.

They gave me a price of 61 euros per unit and I think it's a good option (the price of Avel Lindverg UK is 107 euros per transformer with the same specs).

I know I can use a secondaries with 100mA instead of 150 and 10VA instead of 15, but I'm not sure it's correct voltage in the secondary (2x450v). Can somebody confirm if these specs are correct for a 500v version?

-- o --

Rodrigo

I have a 450V@125mA transformer for SumR sitting in my drawer right now. Specs wise it should be able to provide enough unreg voltage for the 500V supply to work.

Many thanks ujamerstand, I will buy the trafos tomorrow

-- o --

Rodrigo

If someone would like to test them under a curve tracer I'd gladly drop a few in the mail to you for free. album here.

all you need to validate is a multimeter.

If you have a scope and a function generator, it's easier.

How?

Setup a circuit that varies Ib of the transistor. Stick some sort of resistor on the emitter. Stick the X channel on the emitter and the Y channel on the collector. Stick your function generator on the collector and DC bias the transistor and sweep Vce essentially. Stick the scope in XY mode. Capture the waveform. Change Ib, capture again. Repeat.

If you don't have a scope and a AC source? Well just manually plot the IV curve for a few values.

Edited October 14, 201114 yr by luvdunhill

x2

Edited October 14, 201114 yr by luvdunhill

Sounds easy enough. I'll put that on my todo list. I can just vary the base current with a resistor, right? no need for a CCS circuit or anything like that?

Edited October 14, 201114 yr by ujamerstand

The onboard version will fit in the 16x16x4 Par-Metal case. For some reason I thought the latest revision psu made it not possible to do so. There is a little over 15 cm (short length) for the transformer.

Sounds easy enough. I'll put that on my todo list. I can just vary the base current with a resistor, right? no need for a CCS circuit or anything like that?

You got it. Found this which looks like its a lab exercise ....

http://www.atela.uhp-nancy.fr/docs/documents/Traceur_de_courbe.pdf

I'm definitely printing that out. Thanks!

On The preliminary BOM in the board buy thread there is a slight mistake in the spreadsheet for the KGSSHV power supply

The BOM shows the 240K 2W resistors part No. 283-240K-RC as 2 per board. The quantity should be double i.e. 4 per board.

Also, there are 4 0.1uF/1000V caps on the power supply board. Only 3 in the BOM.

It also looks like there are 4 leds per amp board, and 3 listed on the BOM. D1, D2, D10 & D13.

Edited October 20, 201114 yr by wink

Quick question before I power up the power supply for the first time. Is it safe to power up the PS without a load?

So I powered up the Power supply, and I'm getting +/-450VDC. That would be great if I wasn't trying to go for +/-500VDC. I'm getting about 570V if I measure the Bias (before the 5M resistor) to the ground.

I've got a 550V string of zeners (200V + 200V + 150V) at D3, D4 and D5. Under no load, my SumR transformer secondaries are measuring about 520Vac. I have not populated the voltage multiplier parts, and I have soldered a wire at the bypass.

Any ideas of what I forgot to do?

Edited October 17, 201114 yr by Horio

What is the measured voltage across the entire Zener string?

Edited October 17, 201114 yr by luvdunhill

540V on the positive rail, 550V on the negative rail. Are there some resistor values that needed to change as well? The power supply sure thinks its a 450V setup.

Edited October 17, 201114 yr by Horio

The zener voltages are fine. On the board there is a resistor string that is 440K - 440K - 20K. That is setup for 450V. If you want 500V it should be 490K - 490K - 20K.

It forms a voltage divide against the 10V reference so that the 490K - 20K junction should be 10V as well.

Good news is the supply is working fine, just need to change the setup a bit

EDIT: This has to be done for both the positive and negative rails.

Edited October 17, 201114 yr by Kerry

I knew it! I'm putting that correction into my BOM. Thanks!

Edit: Okay, the closest value I could find to 490k is 487k. So I guess that means +/-497V output on my supply. Or I guess I could substitute them with 511k+470k to get +/-500.5V output.

Edited October 17, 201114 yr by ujamerstand

Just realized there isn't a 490K for the Xicon. You can use the 487K or you can leave the 442K and switch the 20K to an 18K. Either will get you close to 500V.