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Diabolical Artificer · 4th Aug 2020, 11:38 am

Ta. So far have 100r gate resistors and 12v zeners from source to gate. as the load in this case has little capacitance not to worried about diode protection across OP.

Putting this through it's paces but noticed regulation isn't good with increased V in. Have paralleled another 68r across R1. With just 68r as R1 and a 3k3 load from power up puts it into current limiting, however with two 3k R's as load on power up, when powered up, V out = 300v, when I shunt one 3k out, V out regulation remains good, EG V dropped by 100mV. So a 3k3 load from power up needs R1 tweaking.

Am using the present CCS with these tests, will leave it on for an hour and see how hot things get then decide if to implement Ref's suggestion.

Lastly, what sort of tests should I be after doing? Vin +/- 10%, load 50mA, 100mA, 150mA, 200mA kind of thing.?

Andy.

4th Aug 2020, 11:38 am	#97
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,662	Re: High voltage regulator circuit. Ta. So far have 100r gate resistors and 12v zeners from source to gate. as the load in this case has little capacitance not to worried about diode protection across OP. Putting this through it's paces but noticed regulation isn't good with increased V in. Have paralleled another 68r across R1. With just 68r as R1 and a 3k3 load from power up puts it into current limiting, however with two 3k R's as load on power up, when powered up, V out = 300v, when I shunt one 3k out, V out regulation remains good, EG V dropped by 100mV. So a 3k3 load from power up needs R1 tweaking. Am using the present CCS with these tests, will leave it on for an hour and see how hot things get then decide if to implement Ref's suggestion. Lastly, what sort of tests should I be after doing? Vin +/- 10%, load 50mA, 100mA, 150mA, 200mA kind of thing.? Andy. __________________ Curiosity hasn't killed this cat...so far.