Hi, I am making something to measure how much time two objects are in contact when one of them is accelerated towards the other. To do this, I'm going to put a wire on one object and another on the other, and make the objects complete the circuit when they touch obviously. What happens with this is is these wires link to a stopclock/watch (i can give the model name if you want) and this stopwatch starts timing when it receives a current and stops when it receives ANOTHER current. I mean, you give it a current. Starts time. You "break the circuit." It still times. You give it another current, it stops. This isn't useful because I need it to start timing when it receives a current and stop when that current is taken away (as the objects are no longer in contact; no more current). What can I do to make this work? Is there anyway I would generate/make a current come when the circuit is broken? How does a potential divider fit into this? I am grateful for help. Thank you.