Interim Linear Actuator driver pcb

 

   I purchased a Chinese four channel mosfet pcb on eBay. As it turned out, the chanels are not isolated from each other but share a common reference ground.

   Recently, I realized I could modify the pcb and use as a reversible H-bridge motor driver. Previouly, I had considered a different design but decided to discard the design. There was no 'off' position. One direction or the other would  always be 'on.'

   Currently, the Qg of 1,4 are tied together as are the Qg of 2,3. This allows only two control signals to run the driver. There is a combination of the two control signals that will allow an 'off' position.

   The Qs of  1,3 were lifted from the pcb and soldered to their respective followers; Q1s --> Q2d and Q3s --> Q4d. This created the necessarily isolation for H-bridge use.

   The images below are before and after using the LSpice XVII simulator. I've not run the simulator yet, but I have successfully built and tested the circuit on my Heathkit breadboard lab.

Before:

After: