Galvano-magneto effect apparatus

Claim 1

A galvano-magneto effect apparatus comprising a. a signal generating source which generates AC signals, b. at least one active element coupled to said AC signal source, c. a feedback circuit having a parallel T circuit comprising 1. a pair of input terminals, 2. a pair of output terminals one of which is short-circuited to one of said input terminals, 3. first and second resistors which are series-connected between the input terminal and output terminal which are not short-circuited, 4. a first capacitor which is connected between said shortcircuited terminals and the connecting point between said first and second resistors, 5. second and third capacitors which are series-connected said series-connected capacitors being parallel-connected with said first and second resistors, and 6. resistance means connected between said second and third capacitors and said short-circuited terminals, said resistance means including a magnetism sensing means the resistance of which is varied in accordance with the intensity of a magnetic field applied thereto wherein the output of said active element is applied to the input terminal of said parallel T circuit and the output of said parallel T circuit is positively fed back to the input of said active element, and d. a magnetism applying means for applying the magnetic field to said magnetism sensing means, wherein the magnetic field applied to said magnetism sensing means is varied by said magnetism applying means thereby varying the center frequency of the parallel T circuit whereby the output of the entire apparatus is varied.