Hi all,
I've a variable rate 12v hydraulic solenoid I need to drive, its around 25w according to me and my trusty multi meter.
I have a circuit setup to drive it with a pwm signal from a pic io pin.
Normal thing I think, 100 ohms from the pin to gate, 100k gate to ground, solenoid coil on the high side.
It worked fine, I was happy! The MOSFET is a irlz (forget the number will look it up in a bit) rated well over the 2A needed.
Its now failed closed. First thought is I forgot to put in a flyback diode, I assume this led to the death of my MOSFET?
If I put a flyback diode in it got me wondering, what frequency should I use? Its running at 1khz now but I guess I need to take account of the diode turn off time?
What frequency would the pros use in this situation?
Thanks Geoff
I've a variable rate 12v hydraulic solenoid I need to drive, its around 25w according to me and my trusty multi meter.
I have a circuit setup to drive it with a pwm signal from a pic io pin.
Normal thing I think, 100 ohms from the pin to gate, 100k gate to ground, solenoid coil on the high side.
It worked fine, I was happy! The MOSFET is a irlz (forget the number will look it up in a bit) rated well over the 2A needed.
Its now failed closed. First thought is I forgot to put in a flyback diode, I assume this led to the death of my MOSFET?
If I put a flyback diode in it got me wondering, what frequency should I use? Its running at 1khz now but I guess I need to take account of the diode turn off time?
What frequency would the pros use in this situation?
Thanks Geoff