I am using uc3843a in my flyback converter.
for now, I'm giving supply to ic with potential divider from the supply of 50 volts which is also input to the flyback.
the converter is working but voltage to Vcc is dropping down to around 8.4 volts which is making it start for some time then stoping it, I will attach a photo of this happening which contains Vcc volts and gate to source volts.
potential divider should be supplying 12v at 50v supply to the Vcc. because I have used 500ohm and 1.5kohm resistor of 1W.Piyush Hirapara said:Part Number: UC3843A
I am using uc3843a in my flyback converter.
for now, I'm giving supply to ic with potential divider from the supply of 50 volts which is also input to the flyback.
the converter is working but voltage to Vcc is dropping down to around 8.4 volts which is making it start for some time then stoping it, I will attach a photo of this happening which contains Vcc volts and gate to source volts.
Hi
If you look at the data sheet you will see that the UC3843A has a startup current and an operating current:
So you need to select the resistor from your 50V to VCC so that it can supply enough current to operate the ic.
It look like at the moment your resistor is too high a value.
Regards
John
