| 摘要 |
PURPOSE:To make the execution easy and to lower the cost, by applying the input inputted to a detecting circuit for the 1st peak value also to a detecting circuit for the 2nd peak value via a frequency selection circuit using two-terminal type piezoelectric resonator. CONSTITUTION:The output of a limiter 1 is fed to a detecting circuit 2 for the 1st peak value and a resistor 5 and a two-terminal type piezoelectric ceramic resonator 6 are connected in parallel, and the output is also fed to a detecting circuit 3 for the 2nd peak value via a frequency selection circuit consisting of capacitors 7, 8 connected between the parallel connection and ground. The output of the circuits 2, 3 is fed to a differential amplifier 4 to obtain an FM detecting output from the output side of an amplifier 4. |
