HIGH FREQUENCY SIGNAL CHANGEOVER SWITCH

摘要

PROBLEM TO BE SOLVED: To prevent switching operation from failing due to the attenuation of a tone signal by allowing a circuit between an input terminal land an output terminal in a tone signal detection changeover switch to have sufficiently large impedance for a tone signal. SOLUTION: The signal channel of a high frequency signal is laid to a terminal 2-1 from terminals 2-2 or 2-3 through the contact of a relay RY and a capacitor C1 and on the other hand, the signal channel of a low frequency signal through which a power supply current is passed but a tone signal is not passed is laid to the terminals 2-2 and 2-3 from the terminal 2-1 through chokes L1 to L3 and the relay contact RY. A tone signal detection circuit 11 is connected to a point that is grounded by a capacitor C2, its output is given to a transistor Q and the relay RY is energized. The circuit 11 is fed from a power supply stabilization circuit 12 and its operation is stabilized.