Wiper Servo and H bridge woes

Community General Discussions
1

Hello All. I have an engine test cell / dyno that I operate the throttle control with a wiper servo.  I set it all up and use a robot power simple H bridge. It works OK.  But recently it the H bridge went to ground.  I think we left the power on all day and stuffed one of the power transistors!

Anyway, I thoygh I could give making my own H bridge a try. So I stumbled onto Krills circuit with the coparitor and trim pot, it looks good.  I built it and tried to make it work which It wont.  Its very jerky and not smooth and all.  ALthough it does respond slwoly to the slide pot direction .

If anyone could offer me some advice I'd be ever so gratefull.  perhaps its just my poor interpretation of the arrangment.

you can see more of it here: https://onedrive.live.com/redir?resid=27DECE4378DD4BC0!405&authkey=!ACUIsMJcRB_0s5E&ithint=folder%2cjpg

Thanks in advance.  Im stuck!

 

2

Home Brew H Bridge

 

  1. Transfer the hand drawn schematic to a computer form. There are plenty of free schematic entry programs available.
  2. Use a simulator to evaluate the circuit prior to building.
  3. Build and test circuit. Compare actual signals with simulator.

 

CircuitMaker is defunct but there a copies available on the web. I also heard that eEDA has a schematic to SPICE function. If you find and use another package, please post details.