Simplistic MosFET HV Shunt Regs

[LouderIsBetter]

Is it possible to run the SSHV2 at lowish voltage and highish current. Such as 100v and 200mA output?

 

[Salas]

100V yes, 200mA no. The particular Supertex parts won't provide.

 

[LouderIsBetter]

What is the highest current it can provide at 100v?
Thanks for your reply!

Mark

 

[Salas]

Near lower depletion Mosfet CCS part's IDSS. It varies per unit. Maybe 100mA plus. To surely go 100V you would need 27K resistors instead of 68K in SSHV2. SSHV1 has much more capability in CCS current by using a single enhancement mode part.

 

[quanghao]

I know,

You run for about 3 minutes, the output voltage will stabilize

 

[quanghao]

Is it possible to run the SSHV2 at lowish voltage and highish current. Such as 100v and 200mA output?

i think SSHV V1 can run 200mA at 100V

V in = 120VDC
So you can set R current all = 230 to 250mA . ( R1 ~ 7-10R )
And you need 200mA, can try to make it!
thanks

 

[merlin el mago]

Salas I want to use only the CCS part of your regulator, could you tell how many volts draws?

 

[Salas]

If you mean how many volts it drops across the cascode, then its about 7 plus whatever mA you set times (R4+R5).

 

[merlin el mago]

With DCin 176VDC & 32,5mA for two #26 tube preamp, tx is 125VDC 100VA , I ask because I haven't enough space to fit a big heatsink for SSHV2, wich will be the minimum heatsink required if I use all SSHV2,because my box is only 40mm high?

 

[Salas]

The sinked CCS Mosfet will burn about 1.5W in that case (with ~30mA setting). So a small one like we use for not too hot LM317 situations will do the job.

 

[merlin el mago]

If I can't fit the heatsink for SSHV2 I will use only your CCS & VR150 tubes

 

[Salas]

Noisier, more Zo, but musical enough.

 

[merlin el mago]

I read VR150 datasheet and said the minimum voltage operation is 180-185V, do you think will operate with 176,25VDC?

 

[merlin el mago]

The sinked CCS Mosfet will burn about 1.5W in that case (with ~30mA setting). So a small one like we use for not too hot LM317 situations will do the job.

That's a very good news because I prefer to use all the SSHV2 in my #26 preamp

 

[Salas]

I read VR150 datasheet and said the minimum voltage operation is 180-185V, do you think will operate with 176,25VDC?

Not sure, I have checked some of those only above 200V in the past. Better ask the #26 guys.

 

[Salas]

That's a very good news because I prefer to use all the SSHV2 in my #26 preamp

But the output Mosfet will burn 3.5W so its sink better be 3x the size of the CCS one.

 

[merlin el mago]

Can be enough this one?

Compre Disipadores Disipador de calor,TO220 3.5degC/W AAVID THERMALLOY KL-100-B en RS Online y lo recibir en 24/48 horas.

 

[Salas]

Yep.

 

[merlin el mago]

This one 3.7K/W also?

Compre Disipadores Disipador de calor,50x100x28mm KL/B/100 AAVID THERMALLOY KL/B/100 en RS Online y lo recibir en 24/48 horas.

N.B. I have this one on hand.

 

[Salas]

Both will do at the CCS and Vo and load you described. They look the same.