hi I know what I want to achieve but not sure how to do it. I used to be really good at electronics at school but that was some time ago now and I fear I have forgotten more than I learned. I am building a model bus layout with a working vehicle. The vehicle has a magnet on the bottom and I have a reed switch under the road which activates an led every time it passes. What I want is a circuit that makes it so the light only comes on every 3rd or 4th time or even better on random passes. I have tried search engines but am that far out of it I dont know what type of circuit I am looking for. can anyone point me in the right direction?