Simplistic MosFET HV Shunt Regs

[merlin el mago]

Puresound phono MM schematic

 

[merlin el mago]

Will be better if someone tell me how calculate?

 

[Salas]

Set each stage reg for 30mA.

 

[merlin el mago]

Thank you.

 

[merlin el mago]

Will be enough this heatsink for IRF9610 & IRF840?

Digi-Key - HS276-ND (Manufacturer - 529802B00000)

It's necessary heatsink for MJE350?

 

[Salas]

Use double the height this kind. MJE needs not.

 

[merlin el mago]

I don't get any double height, can get 1ºC/W that's right?

 

[Salas]

You can use the linked ones for the 9610, but the 840 will be dissipating about 5-6W. Those you linked say they rise 40C over ambient for 8W. So get next bigger size or next higher spec different type.

 

[merlin el mago]

Are too much big, first I will try using the chassis like heatsink, another question about dummy load 10 or 15k 20W wich will value the right value of both are OK?

 

[quanghao]

I don't get any double height, can get 1ºC/W that's right?

You see heatsink,i use in SSHV for Iv stage use tube 6h30, all load near 80mA ad +B 230V

 

[Salas]

Are too much big, first I will try using the chassis like heatsink, another question about dummy load 10 or 15k 20W wich will value the right value of both are OK?

If insulation pad on Mosfet's back fails by heat one time in the future, having the box as a sink its either spectacular HV short to ground when with a grounded box, or DC electrocution hazard for anybody touching the box if ground is not present or faulty. This is high voltage. Don't take it lightly. A 22K 10W will be good for dummy in your case.

 

[merlin el mago]

You see heatsink,i use in SSHV for Iv stage use tube 6h30, all load near 80mA ad +B 230V

This one that you sell in your web:

Heatsinks for IRF9540 + 540 - Quanghao.com

An externally hosted image should be here but it was not working when we last tested it.

 

[quanghao]

This one that you sell in your web:


NO!~
it is ok! IV stage Kit - Quanghao.com

 

[merlin el mago]

I have on hand these of my old V1.0 RS for phono RIAA

ABL Components | Semiconductores | Zócalos, Disipadores y Accesorios | Disipadores de calor | Resistencia térmica de hasta 1,3 °C / W |345AB1000B

 

[quanghao]

I have on hand these of my old V1.0 RS for phono RIAA

ABL Components | Semiconductores | Zócalos, Disipadores y Accesorios | Disipadores de calor | Resistencia térmica de hasta 1,3 °C / W |345AB1000B

I think it is ok!
But how many voltage and mA do you need?

 

[merlin el mago]

I think it is ok!
But how many voltage and mA do you need?

One reg 260V 30mA, the other reg 180V 30mA, it's ok in your SSHV R1 56 ohms or wich will be the value to get 30mA?

 

[quanghao]

One reg 260V 30mA, the other reg 180V 30mA, it's ok in your SSHV R1 56 ohms or wich will be the value to get 30mA?

You use it, last you post :
Digi-Key - HS276-ND (Manufacturer - 529802B00000)

R1 = 20R. I out~100mA

R1 = 22R. I out~80mA

R1 = 33R. I out~60mA

R1 =47R. I out~50mA

R1 = 56R. I out~40mA

 

[merlin el mago]

Set each stage reg for 30mA.

Will be enough this heatsink for IRF9610 & IRF840?

Digi-Key - HS276-ND (Manufacturer - 529802B00000)

It's necessary heatsink for MJE350?

Use double the height this kind. MJE needs not.

You can use the linked ones for the 9610, but the 840 will be dissipating about 5-6W. Those you linked say they rise 40C over ambient for 8W. So get next bigger size or next higher spec different type.

????

 

[Salas]

It says use the small ones you first showed in the link for the 9610 but something bigger for the 840.

 

[merlin el mago]

I mind this one will do fine for 840?

AAVID THERMALLOY | Semiconductores | Zócalos, Disipadores y Accesorios | Disipadores de calor | Disipadores térmicos BGA |637303B03000