Instead of the MCU, I made up this 555 timer circuit to trigger the FET's gate circuit after about 30 seconds. I dicked around with that thing a lot in high school. It was of sorts my favorite component.
- The RC network going to the trigger makes the trigger high after a few milliseconds power is applied. The trigger needs to be low to begin the pulse.
- The RC network going to the threshold and discharge inputs makes the pulse last 30 seconds.
- The 74LS04 inverter inverts the output as the gate circuit of the FET has to be off for 30 seconds and the 555 timer output is high.
What do you all think about this circuit? I do have more experience in the solid state world and making a solid state relay in not that complicated.