Intervalometer

An intervalometer, also called an interval meter or interval timer, is a device that measures short intervals of time. People commonly use such devices to signal, in accurate time intervals, the operation of some other device. The intervalometer measures the intermittent pulses between a starting pulse signal and an ending pulse signal, before a pulse counter measures the number of pulses released into the appropriate time interval. For instance, an intervalometer might activate something every 30 seconds.