POWER SUPERPOSITION TRANSMISSION METHOD, TRANSMITTER AND POWER SUPERPOSITION TRANSMISSION SYSTEM

摘要

PROBLEM TO BE SOLVED: To prevent a failure and a malfunction of non-scheduled connection equipment incorrectly connected to the reception side.SOLUTION: To a speaker cable 5 for connecting a head unit 3 to a digital speaker box 6, before the head unit 3 superposes on a digital voice signal D1 and transmits a battery voltage Va for operating the digital speaker box 6, an incorrect connection detection voltage Vc, which is lower than the battery voltage Va, is applied to the speaker cable 5. In this case, the battery voltage Va is applied when a current I flowing at the incorrect connection detection voltage Vc is a predetermined current Ia or lower.