I hope this isn't too big an ask, The charger isn't actually faulty yet but I am trying to get an understanding of it for when it does. I have attached the circuit diagram and I need a clever electronics expert to give me an idea of what the different parts of the circuit do? I have a few ideas but some of it doesn't make sense, like if you look at the part bottom right consisting of IC2 C and D, because the power fet is an "N" fet you would expect pin 14 to go high when it is charging, but measuring it shows it goes down to about a volt. and up to 8.5 volts when it's not charging.
I thought maybe the two op amps make an ocillator to drive the fet, but the scope shows no waveform at pin 14 when it's charging? I am well confused
IC 2 A and B seem to be mainly concerned with controlling the dual colored led to indicate charging or not
Control of to charge or not seems to be done with IC1 A, B and C making a comparator and comparing the voltage on pin 2 of the power fet with the precision reg which measures 3 volts on pin 6.
Measurement shows pin 8 is 8.5 volts when charging, less than a volt when not.
I think IC 1D is mainly for thermal overload protection?
What do you guys think please?
I thought maybe the two op amps make an ocillator to drive the fet, but the scope shows no waveform at pin 14 when it's charging? I am well confused
IC 2 A and B seem to be mainly concerned with controlling the dual colored led to indicate charging or not
Control of to charge or not seems to be done with IC1 A, B and C making a comparator and comparing the voltage on pin 2 of the power fet with the precision reg which measures 3 volts on pin 6.
Measurement shows pin 8 is 8.5 volts when charging, less than a volt when not.
I think IC 1D is mainly for thermal overload protection?
What do you guys think please?
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