I'm trying to use a micro-controller to activate an opto-coupler connected to 555 timer which is connected to a MOSFET. The circuit will drive a solenoid which draws 2amps at 12v. I'm new to circuit design but have combined a few schematics I have found to come up with the one below. I think I have some resistor values wrong, and I'm unsure if the 555 can drive the MOSFET directly???
5ms pulse fom micro converted to .5 second pulse by monostable 555
R1 470 ohm 1/4 watt) (R2 2.2k 1/4 watt) (R3 470 ohm 1/4 watt) (R4 45k 1/4 watt) (R5 2.2k 1/4 watt(Micro controller to opto =5v) (555timer, MOSFET, Solenoid =12v)
(MOSFET=1PP096N03L) (555= TLC555) (opto=PC817)
- Solenoid is 130ft. of 30AWG magnet wire. 13.4 Ohms
The solenoid in this circuit is coupled with another solenoid, connected to an identical circuit as this one, except their polarity is reversed. So one circuit magnetizes the core in one direction and the other circuit magnetizes it in the reverse. Since they are coupled, one circuit will create current in the other right? Does that cause any problems, or will it be shunted by the diode (BY229)?
Another thing I was thinking about is having an H bridge connected to the 555 and using the same solenoid, instead of having two. I'm trying to keep the cost down as I need a number of these circuits, and an H bridge design seems to be more expensive from what I can find. Thanks