tomoki

Office day is a debug day~~~ I just start measuring the current for 2 10M90S, result is quite..............strange.........I Just upload photos to show what I get. For the +VE board For the -VE baord I think I know what you guy talking about variac. Using variac means that when the first time start we should use the variac to power the board and setup the voltage slowly (per you guys suggestion, 40-50V first). Am I right?

Thanks for your comment and kindly remind. the mica that i use is the ceramic type one with nylon screw and nuts For the variac, I still feel a little bit confusing about the connection method. BTW, due to my job I can try my office AC power stabilizer, I think it can tune the voltage that required. Thanks for your advise. I am wonder both 2 are broken. planning to replace it both. Thanks sorenb. Just a little bit confusing the method and I would like to confirm it before test it. For the CCS, is that I should use a AC source with voltage in between 15-20VAC, then connect it between the middle leg of the 10m90s and solder pad in between R2 and R1 (also the pin 6, for the 2nd 10m90s).

Thanks for your comment. The input voltage is 360VAC and suppose the output shall be 400VAC Those 2 390K resistors are replaced to the 442K resistor I atttached the photo again

Thx for the comment, confirmed the 20K resistor is not shorted.

Thx for comment. Originally the angle bracket is not shorted with the resistor, it is just because the M1090S mica set and the screw are taken out. The time I power the board this angle bracket are screwed in tight without short upload a photo again to avoid mis-leading

hi all， im new to this DIY scene but i got a problem with the HV board. the 20K ohm resistor is kept burnt even both the M1090S are checked as broken and replaced a new one. Any body can give me some advise to fix this issue? It was burnt even in 450V no load conidition.