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Happy Birthday!!

One other thing I would add to James' excellent check steps would be to check the SMD resistors to make sure they aren't shorted. I had this happen with a couple of 0805 resistors on a mini dynalo, and could not see anything under magnification (OptiVisor 10X lenses). This might not be an issue with 1206/1210 packages though, or as much of one. Mine were all hand soldered. Using paste and a stencil might make this a non-issue.

Happy belated Birthday Ric!

Happy Birthday Joachim!

Happy belated Birthday Ken!

Merry Christmas!

Yeah, that was disturbing. We used to watch him on SYTYCD when he was competing, and he seemed like a really nice guy. Sad.

According to Octopart, Winsource Electronics has 6300. Pricey ($22@+), not sure if they're reputable. My guess is no, but only a guess.

Happy belated birthday!

Happy Birthday Todd!

Tested the negative GRHV today, same performance. Was regulating at -55Vdc with the 100K resistor in. Removed it and tested at full voltage. -406.5Vdc, stable. Now for the Carbon boards.

Happy Birthday! I hope you have a great one Bryan!

Just a quick and stupid question: when testing amps/psus not in a chassis, do you tie any heatsinks to safety ground just in case? Just thinking that might be a good idea, particularly on HV stuff.

Happy Birthday!

OK, powered up and works great. 406Vdc, stable. Bias is 576-580 at bias TP (drifting up a bit). What is the max for pro bias?

Yeah, when Soren said to measure the current limiter, I was just injecting a + voltage at point A3 with the negative lead at B3. Ammeter in series with the power supply. I know the 5.1R is the current limiter. Maybe I should inject the voltage at A3-B3 and measure the voltage drop across R11 instead? I'll probably remove the parallel 100K and test at full voltage. Since it was regulating at 55V, it should be fine? Seems like everything is working correctly.

OK, finally getting around to testing the GRHVs I'm building for the Carbon. Using Soren's post on pre-testing, I had some variances. I marked up the schematic from James above. For the first test, using ~17Vdc thru an ammeter, I'm getting 0.5mA (not 2mA) (points A1-B1) For the second test, I'm getting ~1.3-1.4mA (points A2-B2), which matches Soren's figures. For the third test, I'm getting 10.5-10.9mA (points A3-B3). This may be referring to a Megatron HV900 PSU in Soren's notes below, and I'm not sure I'm looking at the correct points anyhow. I have a 100K resistor paralleling the two 390Ks. Bringing the positive supply up on a variac until it regulates, it seems to be regulating at 55Vdc, which is about what I calculated. Boards are 1.8 version, single fat sw variants. The voltage appeared to be stable; raising the variac a bit didn't change the output. Just checking because the first CCS test was considerably lower than what Soren saw. I did unsolder one end of the 100K resistor and rechecked, but no change. Any thoughts, or just go for full voltage?

Happy Birthday JP!

Toto, I don't think we're in Florida anymore...

Happy Birthday Dinny!

ChipOneStop shows some stock, not sure how trusted they are. https://octopart.com/dn2540n5-g-microchip-47153345?r=sp

Happy Birthday Chris! Don't catch too many fish...

Happy Birthday Mikey!

I usually solder at around 700F (or up to 750), which is higher than your temp. Where did the boards come from? I haven't had problems with lifted pads in a long long time.

There are BOMs in the thread, but I've attached one here. There are alternate parts for some items, so check it over before you place an order. You can oftentimes save money by buying in quantity, particularly the SMD resistors (100 isn't unreasonable). The pricing in this isn't accurate as well. Read thru the thread regarding cases (or search). ssdynalo-v1-4.xlsx