Microprocessor controlled strongest signal selector for vehicle radio - compares strength of two carrier wave signals to determine whether modulated signals are identical

摘要

Two FM tuners and an AM tuner provide inputs to a microprocessor in which two program elements provide frequency control signals. There program elements are connected to a control circuit to command a switching circuit to connect the output of one tunes to the audio circuits and loudspeaker. The IF amplifier outputs for the FM tuners provide signals for shaping circuits for input to the microprocessor. A comparator determines the strongest signal and an identification circuit provides binary output identity signals for the microprocessor. The microprocessor then issues control signals to connect the strongest signal to the loudspeaker. Control signals are issued to provide frequency sweeping on the other tuner to maintain the monitoring process. Manual tuning is performed via the program element in the microprocessor.