Abstract: A motor vehicle alarm system incorporates five integrated circuits mounted on a printed circuit board enclosed within a case. The integrated circuits include a high speed oscillator as a clock source, a twelve stage binary counter, a set of flip-flops used as memories, a three input AND gate, and a flip-flop used as the start or stop memory for the clock source. The alarm system becomes armed approximately four minutes and fifteen seconds after the ignition key is turned off. If a door is then opened, the alarm will be actuated unless the ignition switch is turned on within fifteen seconds.