Poly, I thought about using a 555 or logic chips, I'm trying to develop my bare metal skills is all... if it had of been say 12v in and if the power went out, a simple pnp would handle it..
But because I want the 5v to control the circuit, a 5v high would not switch off a pnp when the emitter has 12v on it..
I was after criticism of this circuit, alternatives would be quite simple I have a draw full of logic chips to do such a job, but it's about learning, I could add schmitt trigger in transistor form...
Paul, where does it state it has to be arduino related? This is /general electronics/