TIMED ALARMING USING LOGICAL INVERTERS

摘要

TIMED ALARMING A triggered before disarmed alarm system especially useful in connection with an automobile alarm uses CMOS circuitry and appropriate supply filtering having one hex-inverter integrated circuit as the only active component beside the output transistor. Diodes couple a negative immediate trigger, positive and negative delayed triggers and a disarm potential to various ones of the six inverters to render the output transistor conductive and signify an alarm condition only when an alarm condition is signified by a sequence of inputs consistent with unauthorized entry.