Peak detector for nimh charger

[dany.1986]

Does anyone know simple peak detector circuit that I could use as a termination method for nimh charger? I have looked everywhere but I cannot find anything with good description about how the circuit operates. Please help.

 

[Audioguru]

Why not use a smart battery charger IC? Maxim-IC have some.
The datasheet has a good description about how the circuit operates.

 

[dany.1986]

I don't want to use any IC's. Charger is supposed to charge one nimh battery so
-ΔV will be very small. I need something very sensitive to detect the peak. I found and changed circuit which uses op-amp but I'm not sure if it will be sensitive enough to detect the peak.


In above circuit capacitor connected to non-inverting input has greater delay than C3. So voltage on C1 lags behind voltage on C3 and when peak occurs then output of op-amp is on. What do you think about the circuit? Is it gonna work in practice? Can I do any improvements to it?