Hi Guys, and have searched the forum for answer to my question but I can not seem to find the exact answer/scenario I am trying to achieve. I am trying to build an electrical circuit to pulse a fuel injector off of a Evinrude E TEC outboard motor. It's different than any other fuel injector out there. First of all it operates on a 55 volt dc signal. The voltage is flipped to open and close the injector. So 55 volts positive to open the injector and then 55 volts negative to close the injector. What I was thinking was a 12 Vdc to 55 volt transformer to an H Bridge ( to flip the polarity) to the fuel injector. I am not sure what I need to control the h bridge to rapidly reverse the polarity. Can somebody please help? Or if you have another idea please share.