The ELM307 is a retriggerable one-shot circuit that has been designed for electronically controlling the shutter of a film or digital still camera. The circuit provides a variable pulse width timer, a variable delay reset timer, power control, and an LED status drive all in an 8 pin package. In operation, a monitored signal (alarm contact, audio signal, oscillator signal, etc.) is applied to the circuit's Trigger input. A low level at this input immediately causes an output at the Camera pin (controlling the shutter) that lasts for the duration set by PW. Further triggering is inhibited until an additional period (set by Delay) passes, allowing time for the film to advance or for the digital image to be stored.