Abstract:
A multiplex system for controlling and sensing various component parts such as head lights, engine temperature, fuel level, and turn signal lights is disclosed. The system employs a single twowire cable to communicate both power and signals between such components and a central control and metering console which may be the instrument dash console. Time multiplex is employed using a reverse polarity for clock pulses from that of the information pulses. Both analog and digital data may be accommodated by using pulse-width modulation as well as bi-level modulation. Receiving units employ a N delay one-shot triggered by the clock pulse and an AND circuit driven by the output of the N delay one-shot and the signal present on the single signal wire, to drive a one-shot which controls a switching device. Similar circuitry is employed for the digital transmitting and the analog transmitter and receiver. A socket input unit for tapping into the single cable in parallel to other input units by employing a piercing plug is disclosed.