Abstract

A monitoring system for the notification of locations external to the area being monitored of a prolonged absence of motion within the area being monitored is disclosed consisting of a clock, an electronic counter designed to record the pulses emitted periodically by the clock and to signal an alarm trigger when a pre-programmed number of pulses are recorded, and reset means such that if activated the counter will return to zero thereby preventing activation of the alarm trigger. Also, this system uses circuit means incorporating a photoelectric cell to automatically increase the pre-programmed number of pulses necessary to cause activation of the alarm trigger during periods of darkness and to automatically return the counter to its original pre-programmed condition with the presence of light.