The Stax Thread III

[etc6849]

Hope not. The mouser URL, mouser part number, manufacturer part number, spec sheet all say 600P means 600VDC positive. Plus the images on mouser, always have the disclaimer on them... Stranger things have happened, so not saying you are wrong lol.

 

[bearFNF]

Hope not. The mouser URL, mouser part number, manufacturer part number, spec sheet all say 600P means 600VDC positive. Plus the images on mouser, always have the disclaimer on them... Stranger things have happened, so not saying you are wrong lol.

I meant the first link you posted to xppower in your initial post about this (on the xppower site)... not really an issue and not trying to argue about anything.

 

[etc6849]

No worries. That link just takes to you a discussion of the HRC05 series, as it discusses in many places on that page. Which is why my post also included the spec sheet, listing the individual part numbers under the HRC05 series. I probably could have just linked to the 600V one in my first post

 

[kevin gilmore]

you definitely want a fully isolated part. common ground input to output probably a bad idea.

 

[aokman]

I finally built the bias board @aokman designed. Only one small change: I added an inline switch off a jumper that's downstream of the fuse as I wanted to ensure the switch was included in the fused circuit.

I really like the board design. Measuring less than 100mV ripple at 580VDC. Running it off a 9V power adapter, and the regulator works great. I didn't test it's very large input range as the LED circuit is designed for 12VDC, so I can't exceed that.

If anyone builds this, just be sure to buy a bunch of 5.1V zener diodes, and measure the reverse bias voltage. As aokman says in his video, you are looking for one that is very close to or around 5V. If you install one with too low of a Vr (as measured in the pic below), it will switch the thyristor on, which will pull down the input voltage going into the DC-DC converter as it's trying to "protect" the circuit from the over voltage (set by Vr of the zener). My voltage at test point 2 was around 4.78V for 580V out. All 10 of my zener diodes measured 4.3-4.4V, so they weren't going to work. Luckily I found one in an old kit with a higher Vr, around 5.1V.

Glad to hear you got one running sorry been taking a break to restore some amps as I was burned out from estat stuff

I agree that UHV has no experience dealing with English-speaking clients. But I've been down that road before and at least they give an output voltage and current. Personally I'd prefer a regulated supply to keep the ripple down. An unregulated DC-DC converter can be rather noisy. I'll let you know the ripple of the UHV once I have breadboarde the ciruit. And keep in mind that putting an overvoltage circuit on the INPUT of the Enco does not protect its output from over voltage!!! You still need protection on its output. Dr. Gilbert suggested a 10K R in series with a nominal 600 V string of Zeners across the 5M buildout resistor. I would do that whichever route you choose, the Enco or the UHV.

The output voltage is relative to input voltage and load. I evaluated zeners in series etc on the output HV side but the variance between cumulative breakdown voltage variations and running strings of zeners was too unpredictable… The XP power does have over current / dead short protection though. I researched failure modes for the XP power DC-DC converter and there is absolutely no way for it to generate excessive output voltage without the input voltage going high also.

I pondered this for almost a month and tested both input and output side protection setups but doing things on the HV side just didn’t feel right. Not to mention the XP power is still expensive itself so it deserves protecting also and it will fail if the input voltage goes too high.

This is why I run an input fuse, followed near max current limiting on the LT3081, then finally a last resort crowbar that will short the input of the converter if the regulator was to fail.

you definitely want a fully isolated part. common ground input to output probably a bad idea.

XP power application guides allow for either but I agree floating the output worked best for me and was the cleanest.

At the end of the day I provided my results and design just to give back to the community, I have tried to cover as much as I can and the first iteration using just a LM317 ran for over 6 months with 0 issues and that had nothing but a fuse to protect it.

I have not measured any significant changes in output voltage with connected estats, the converter isnt “that” sensitive. Worst case an increased load would pull down the output voltage a little more and I usually keep the bias around 570-575V.

 

[oneguy]

Any of you nerds want in on this fraternity?

 

[DougD]

Impressive.

I only need 7 more to catch up.

 

[oneguy]

Impressive.

I only need 7 more to catch up.

Better make that 8 because I have another one on the way.

 

[DougD]

Better make that 8 because I have another one on the way.

The race is over, we have the winner.

 

[oneguy]

The race is over, we have the winner.

no there are some out there that have me beat

 

[Svperstar]

Any of you nerds want in on this fraternity?

Any chance of getting this picture but high res enough where you can read the labels in the back?

 

[oneguy]

Any chance of getting this picture but high res enough where you can read the labels in the back?

This is the best I could do with my 4 year old iPhone.

https://www.imghippo.com/i/7FmNL1727731249.jpg

 

[number1sixerfan]

Better make that 8 because I have another one on the way.

Oh, that's a real picture of yours lol. That is insane lol

 

[TheAbyss2022]

Any of you nerds want in on this fraternity?

Do these older models run at 230v?

 

[oneguy]

Do these older models run at 230v?

The Lambda (far left) is the only one that runs on 230v bias. The rest are all Pro Bias.