10~12V Opto Gate Driver and Back EMF, EMI Problems
1. Now I am designing a 12V gate driver to drive 1st to 3rd generation (IRF540N to IRL540N) power MOSFETs. The Rpi ground and optocoupler (EL817C) ground are NOT connected, for total optical isolation.
Gavinmc42 wrote: ↑
Thu Feb 07, 2019 8:41 am
1. An optocoupler driving the gate will help.
2. If that Solenoid diode cannot handle the spikes then there will be induced spikes everywhere.
3. Solenoids are not much different than those ignition coils in cars, zap.
4. Try to electrically isolated high voltage/high current stuff from low voltage Pi's.
5. Opto relays make it simple and safer.
2, 3, 4. The power MOSFET is used to drive motor, solenoid, and solenoid valves, all of which have back EMF and EMI which I know will cause problems. I am not sure at all if I can solve these back EMF, EMI problems.
5. I know electro-mechanical relay switches are safer, but they are too bulky. I read that modern cars have hundreds or thousands of power mosfet switches inside. So my dream is to DIY a toy car with at least 100 power mosfet switches which of course need to be very small, all SMD sizes perhaps.
https://penzu.com/p/6c2c53f4 (Smart City Smart Cars)
- gate_driver_2019feb2001s.jpg (182.53 KiB) Viewed 1052 times
Last edited by tlfong01
on Fri Feb 22, 2019 3:06 am, edited 1 time in total.
I am an electronics and smart home hobbyist.