MOSFET drive circuit

Thread Starter


Joined May 1, 2020
Hello everyone,

I have made a schematic (circuit) (attached as jpg) following layout on the PCB board that I found in battery charger device.
Don't know if I have done a good job and is this circuit made correctly.
It looks like a MOSFET drive circuit, but can not understand the function.
I would like to learn and understand function of this circuit.
It would be really great when someone can explain me how does this circuit works and diodes (D1, D2, D3), which type of diodes are they, MELF package, marked with a blue band, Vf = cca. 0,20V.

Thanks in advance.



Joined Mar 30, 2015
Welcome to AAC!

Is this something you drew? Or a design you copied from somewhere? It has a number of problems.

There are no component values, ground connections are missing for TR2 and TR3, R6 is shorted.

I removed a lot of white space to make the schematic easier to read.

Thread Starter


Joined May 1, 2020
Hi Dennis,
I have a PCB board that I took out from a battery charger device. I tried to make a schematic just following a layout.
I would like to understand how does it work. I know some types of MOSFET/IGBT gate drive circuits, but this one looks strange.
Battery charger output is Vout=24VDC, Iout=60A.
Component values can give you on Wednesday. Must check out the connections form TR2 and TR3, and tat part with a R6.
There are some diodes, MELF, (D1, D2, D4), they are burned. Would like to replace them and try to repair device.