Salas I only get max. 30mA CCS with 150VAC tx, what's the possible issue? I use CCS 30mA as load, also I use 100R 100uF to split B+ for both channels. R9 & R10 both are 56K in place of both 68K. The SSHV2 CCS works well to max. 30mA, I tried to lower the CCS load to 20mA but the same problem SSHV2 max. CCS 30mA.
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Maybe the reg's CCS doesn't work and it shows just what is pulled at its output. Try test it with simple resistor as a load too.
From your trouble shooting "The JFET must be producing low and trimmer controlled current. About 2.2mA for 300V." How to measure?
BJTs KSA1381
Q4 seems OK Vbe 0.6V
Q5 seems gone Vbe 0.05V
There is a way to measure the JFET Q6 & the mosfet Q3 to know if are OK or not?
JFET's current can be calculated by mV drop on the resistor and trimmer paralleled between it's gate and source i.e. across R12. Voltage / Ohms of those.
JFET is not drawing none current, voltage accross R12 470R is 0.034V with 170Vout. Can be Q5 isn't damaged?
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Replaced with a new JFET Q3 0.035V across R12 (still not OK)
Q5 Vbe 0.048V (can be due to JFET isn't drawing enough current)
I will check R11 1K trimmer.
Q5 Vbe 0.048V (can be due to JFET isn't drawing enough current)
I will check R11 1K trimmer.
Was Q5. Now can set the SSHV2 CCS to 50mA & adjust Vout but I have a problem CCS load can reach 15mA each channel, only one channel 13.5mA max. and the other 11.1mA. CCS load tested without SSHV2 & reach both channels 15mA each, attached CCS schematic used.
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Try 100 Ohm resistor in series with reg outputs and CCS loads to buffer possible difficult interactions.
Used 100R in series & 100uF in parallel between de SSHV2 & the CCS load as you suggested to split the B+ for both channels. Have I to get off the parallel capacitors?
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what do you think about using something like this to get raw 400V dc for the regulator: 3A Rectifier Filter Power Supply Board Audio Amplifier Single 18V AC-DC Convert | eBay Of course changing all component for proper voltages? Space is tight, so looking for something small...
Given that you find proper sized HV cap and high PIV bridge that fit well I am afraid of narrow space between adjacent copper lanes at places. Although the bottom side pictures are blown out and I can't say for sure. HV needs safe distances not to arc over.