NOVEL THRESHOLD SENSING SWITCHED FILTER.

Abstract

A frequency selective switch is required in many applications such as FSK, voice operated relay and multitone dialing. A scheme for implementing such a switch using a tunable band pass filter has been proposed and evaluated. The pass band of the proposed scheme can be controlled with the help of a reference voltage. The prototype developed has offered a minimum of 2. 0 Hz bandwidth over audio frequency range. However, the principle can be extended to any frequency band.