just another update, fortunately i've got from a friend another shunt HV board made by Quang Hao (thanks Piero7), populated and connected the board in place it works perfectly, with a dummy load (6,8k 10W resistor), changed again the board with the Oliver's one and dummy load again Vout=Vin-2V
for sure i'm doing something wrong, please Oliver and Salas check the pics posted before if everything is in the right place and orientation
for sure i'm doing something wrong, please Oliver and Salas check the pics posted before if everything is in the right place and orientation
HV-Shunt Module schematics
An externally hosted image should be here but it was not working when we last tested it.
i did, tried a third board by Oliver, same result, with R1=33 Vout=Vin-0.8v
i quit.. 😡 i can't figure out what's wrong.. quanghao boards works like a charm in the same dac..
i quit.. 😡
i can't figure out what's wrong.. quanghao boards works like a charm in the same dac..
of course also removed the heater lifter... please forgive me... are you perfectly sure that you have the desired voltage drop between input and output in your board with everything connected? could you check? because it is very strange for me....
no... i tried first the other boards before starting desoldering....
i'll start with that one and then the smaller ones...
i'll start with that one and then the smaller ones...
Tfan69
Double Check everything! From the exact name of the transistors (made this mistake myself once - Salas spotted it!
) to the soldering (on both sides, particularly the one where it meets the trace) to the resistor values (mixing R & K for example).
Double Check everything! From the exact name of the transistors (made this mistake myself once - Salas spotted it!
) to the soldering (on both sides, particularly the one where it meets the trace) to the resistor values (mixing R & K for example).
I find that the "-" trace on the removed capacitor is the perfect place to put the shunt module GND.
Not why you're having problems, but you'll need some heatsink paste on those transistors.
used already the "-" 😉, i added thermal paste 😛
i read:
IRF840
IRF9610
MJE350
K170GR
here's my order from mouser
i read:
IRF840
IRF9610
MJE350
K170GR
here's my order from mouser