With the IR2153 and 1N4007 and 10R dropper in each of HV dc supply and hot
side of hottest mosFET and 57 percent of mains there is life
Blue power LED on, SMD LED D20 on, fan on, +/- 31.6V on main rails , 7.7V on
12V 7812, -9.6V on 9812 and 9.2V on 7814.
Then hot side , 12V on new 10uF C67 and 13.5V on new 100uF C69.
But a minute in and that 4007 smokes and mains current draw rises from
nothing readable on variac AC analogue meter to about .15 amp and I switch
off. 4007 survives as does the IRF740.
Is this a result of me trying to run on too low a HV dc and removing
droppers and taking mains to 75 percent or so will remove this or something
else wrong. I cannot believe that bootstrap diode would be more than 1 amp
inside a D suffix 2153 DIP8 package.
I have the fall-back option of refitting the original driver chip but think
I'll carry on with the replaceable 2153 for the moment, monitoring the
voltage on the R78 Vcc dropper , first I think, in htat first minute