Power Inverter for shallow well water pump motor


I'm in term of project using Arduino MEGA 2650 for generating PWM with digitalWrite() in single phase inverter for controlling rotation speed of my shallow well water pump motor. The schematic is below. 12V in the picture is the pulse that has been gained and isolated with opto-coupler.

Now, I am troubled with my inverter because the mosfets don't have same voltage in pin gate and source each other. The left-above and right-below mosfets have 12volts and have pulse. On the other hand, the others are zero volt. would you help me how to get the same voltage in each gate-source mosfet?

Thanks for help,


This is the schematic. I apologize because I got a technical problem while uploading.

You are lacking a MOSFET driver chip with bootstrapped high-side drivers. Look at the datasheet for the HIP4081A for inspiration. There are many others available, usually 1/2 H-bridge, so two are needed, but the HIP4081 is full H-bridge and there are 3-phase bridge drivers too like the FAN7388

You haven't posted specs for your motor - an existing motor driver board may fit the bill too.

Standard opto-couplers are often too slow for PWM gate drive, note(*). Use specialist MOSFET gate driver chips to drive MOSFET gates unless you've a compelling reason not to. If you do use opto couplers use logic-speed opto-couplers on the inputs to the gate drivers.

(*) result is overheating MOSFETs, as they are being switched far too slowly (many us, rather than a 100ns or so).

The motor is induction single phase asynchronous motor that needs 300 Watts and give 125 Watts in 50 Hz. It runs at 3000 rpm in 50 Hertz with 2 pole.

Can I use tpl250 instead the gate driver that you've recommended?