AM STEREO RECEIVER

摘要

PURPOSE:To improve the detection accuracy of a stereo identification signal by providing a counter circuit counting a clock signal in response to generation of a pulse signal and a discrimination circuit discriminating a stereo identification signal in response to a count of the said counter circuit. CONSTITUTION:A counter circuit 21 starts counting a clock signal when an output pulse of a pulse generating circuit 19 is logical H and stops counting the clock signal when the output pulse is logical L. The frequency of the clock signal is constant and the width of the output pulse is changed depending on the frequency of a stereo identification signal. The count of the counter circuit 21 is fed to a discrimination circuit 22 after the end of count and the said discrimination circuit 22 makes discrimination. The discrimination is attained by setting a data corresponding to the 1st-3rd identification signals into the circuit 22 and comparing the count of the counter circuit 21 with the preset data.