• Disclaimer: This Vendor's Forum is a paid-for commercial area. Unlike the rest of diyAudio, the Vendor has complete control of what may or may not be posted in this forum. If you wish to discuss technical matters outside the bounds of what is permitted by the Vendor, please use the non-commercial areas of diyAudio to do so.

OLD THREAD Simplistic Mosfet HV Shunt (The Simpler Simplistic Design by Salas)

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
pinholer

pinholer

Member
Joined 2010
Paid Member
PCB Group buy, round 2. Please Update the list yourselves when you type:

you can add your name in here please:

1. presbel = 2 pcb ( 4HV shunt + 4 Filament)
2. m461c14n = 1 pcb
3. kstlfido = 2 pcb
4. Sorr = 1 1/2 pcb
5. ksnider1 = 2 pcb
6. fredlock = 1 pcb
7. pinholer = 1 pcb
 
J

j45yip

Member
Joined 2004
PCB Group buy, round 2. Please Update the list yourselves when you type:

you can add your name in here please:

1. presbel = 2 pcb ( 4HV shunt + 4 Filament)
2. m461c14n = 1 pcb
3. kstlfido = 2 pcb
4. Sorr = 1 1/2 pcb
5. ksnider1 = 2 pcb
6. fredlock = 1 pcb
7. pinholer = 1 pcb
8. j45yip = 1 pcb
 
P

presbel

Member
Joined 2006
cats.edu.ph
Originally Posted by pinholer
PCB Group buy, round 2. Please Update the list yourselves when you type:

you can add your name in here please:

1. presbel = 2 pcb ( 4HV shunt + 4 Filament) - already received the PCB
2. m461c14n = 1 pcb
3. kstlfido = 2 pcb
4. Sorr = 1 1/2 pcb
5. ksnider1 = 2 pcb
6. fredlock = 1 pcb
7. pinholer = 1 pcb
I was included in round 1
 
J

j45yip

Member
Joined 2004
PCB Group buy, round 2. Please Update the list yourselves when you type:

Note
1Pcb have: 2 SSHV + 2 filament!

you can add your name in here please:

1. m461c14n = 1 pcb
2. kstlfido = 2 pcb
3. Sorr = 1 1/2 pcb
4. ksnider1 = 2 pcb
5. fredlock = 1 pcb
6. pinholer = 1 pcb
7. j45yip = 1 pcb
 
N

Nikon1975

Member
Joined 2009
Now the fun comes :)

110 mA 390 V with resistor load was OK, but it did not like the soft start of the tube.

D.
 

Attachments

  • IMG_2637.jpg
    IMG_2637.jpg
    123.8 KB · Views: 345
N

Nikon1975

Member
Joined 2009
The heatsink is supposed to be 100 W, I applied first to a resistor, managed to adjust the voltage and everything was OK. Then I tried with the amp, but I did not pre-heat the filaments, so I guess that at startup there was no load. Voltage raised and first BUM (I guess the led) then smoke. From what I see R1 and R2 are gone and one of the leds. I suppose that also the semiconductors will not be so happy. What would you unsolder first, to check if they are fried ?

D.
 
Salas

Salas

diyAudio Chief Moderator
Joined 2002
Paid Member
Nikon1975 said:
The heatsink is supposed to be 100 W, I applied first to a resistor, managed to adjust the voltage and everything was OK. Then I tried with the amp, but I did not pre-heat the filaments, so I guess that at startup there was no load. Voltage raised and first BUM (I guess the led) then smoke. From what I see R1 and R2 are gone and one of the leds. I suppose that also the semiconductors will not be so happy. What would you unsolder first, to check if they are fried ?

D.
Click to expand...

Hmm... the destruction shows strong current through Rset (R1), gate stopper (R2) and LEDS. CCS Mosfet and LEDS must have turned to paths then. CCS Mosfet should be checked for sure, and if still a problem occurs, the 2SA1626 (400V MJE350 sub in your 400V application for people to understand). There is a 47R feeding the 100uF LEDS cap. That helps some performance parameter a little, but if you jumper the 47R, and feed the 100uF directly, the LEDS will bias the CCS just one moment faster on startup and that may be critical or not in your experiment. What kind of circuit are you trying to supply, can you describe? Those regs have been used on phono and line applications, an amp feeds B+ through an OPT with large inductance, could be a strong oscillation by driving inductance. I am happy that it could work at 390V 110mA on a dummy, but interfacing to a cct as a load at such voltage and power levels takes some info. Maybe incompatible, or just needed to preheat as you said. Could have shown some behavior when coming up. See first it works on the dummy again. What consumption was that test load resistor creating?
 
N

Nikon1975

Member
Joined 2009
I was surprised that the 100 uF 10V cap did not explode after the diode. If the diode was open there was nothing clamping the voltage below 10 V around it.

I was testing with a 2 20K 25 W resistors in parallel. This was passing around 40 mA in the resistor and 70 mA on the shunt. But I have to admit, I was kind of fast in adjusting the voltage. :)

I am trying to feed one channel of the Abdellah amp. (Attached)

D.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom