Simplistic MosFET HV Shunt Regs

[merlin el mago]

LED's also burned

 

[Salas]

Debug, make P2P, whatever.

 

[merlin el mago]

I changed the IRF9610, the 220R gate resistors and all LED's but now LED's don't lid

The pcb isn't mine....

 

[vgeorge]

Today I did some testing on the SSHV2.
Nothing I can see on my 20Mhz scope.
It is not with a dummy load, but feeding a ll1660 transformer.

 

[dodo]

what kind of CLC or CRC combination you have before regulator entry?
what was the distance between regulator and load?
if the distance is more then 10 cm will you get the same results applying 4-10uF MKP cap just near the load ?

 

[vgeorge]

CLC on the ps box and RC close to the reg. Load max 15cm from the reg.
You shouldn 't have a cap after the regulator. Don' t forget that SSHV2 has remote sensing.

 

[regal]

Impressive scope shots, I'm upgrading the OPT's on my SSHV1 headamp to parafeed and might has well upgrade to SSHV2 at the same time, where are folks finding the Jfet (USA) ?

 

[merlin el mago]

Debug, make P2P, whatever.

Is dead the mosfet if is not voltage between G & S of IRF9610?

 

[Salas]

Yes. But if you don't give total account of what happens, where you connect, voltages, currents, what is on the build, pictures, nobody can give you a correct idea of how to debug that PCB.

 

[merlin el mago]

Yes you have reason, at this point I don't trust in quanghao SSHV pcbs due to the fact is the second that have issues, I will make a new P2P, BTW do you know when will be released the GB for your SSHV2?

 

[merlin el mago]

You mean you like it in black too I guess.

Yes, sorry I don't read this post till today

 

[merlin el mago]

Hey Nick, see this pic.

 

[merlin el mago]

Vin 284V

 

[Salas]

Don't know about SSHV2 GB, when we will get more feedback on the protos I guess.

 

[merlin el mago]

LED's all also burned

 

[merlin el mago]

It's very strange that two different SSHV pcbs with the same issue:

47R burned
220R burned gate resistor IRF8610

I suspected of the PSU, but I tested and is stable Vin 284VDC, any idea?

 

[vgeorge]

One more picture of the SSHV2 on the scope.
AC max gain 5mV division.
Phillipe, did you test the regulators with dummy load, say 15K first or you put them on the circuit?
Also it' s good after a fault like yours to remove and test all the semiconductors. You never know what can get burned.
When you say PSU, what do you have? Have you simulated it on PSD2?

 

[Salas]

One more picture of the SSHV2 on the scope.
AC max gain 5mV division.
PSD2?

Excellent stability in your P2P builds. Especially when the trace is taken live on your number 26 feeding through its output transformer. Congratulations.

 

[Salas]

It's very strange that two different SSHV pcbs with the same issue:

47R burned
220R burned gate resistor IRF8610

I suspected of the PSU, but I tested and is stable Vin 284VDC, any idea?

Merlin see what's wrong feeding, grounding, or loading the regs. Something's fishy when two different ones give smoke.

 

[merlin el mago]

One more picture of the SSHV2 on the scope.
AC max gain 5mV division.
Phillipe, did you test the regulators with dummy load, say 15K first or you put them on the circuit?
Also it' s good after a fault like yours to remove and test all the semiconductors. You never know what can get burned.
When you say PSU, what do you have? Have you simulated it on PSD2?

I have CLC, tx is Bartolucci 200VDC choke is Bartolucci 10H 100mA, all caps are lytics C1 660uF 450V & C2 300uF 350V