Remote control receiver responsive to sound

Claim 2

A circuit for discriminating between sound signals, which are generated by a transmitter and which have at least one predetermined frequency, and noise signals, said circuit comprising: A. electro-acoustic transducer means for converting the transmitted sound and the noise signals into electrical signals; B. variable gain means for amplifying the electrical signals; C. control means responsive to the amplified electrical signals for producing a controlling signal in response to the amplified signals, said control means being connected to said amplifying means to control the gain of the variable gain amplifying means, said control means comprising a time constant circuit having a shorter time constant and a slow discharge time constant; D. means for converting the amplified electrical signals into corresponding direct current pulse signals whose durations are representative of the length of time that the amplitude of the amplified electrical signals is above a first predetermined voltage level; E. means responsive to the integrated direct current pulse signals for producing output control signals representative of each integrated direct current pulse signal whose amplitude exceeds a second predetermined voltage level.

Claim 3

A circuit as recited in claim 1 wherein the gain control means comprises means for controlling the gain of the variable gain amplifying means inversely in proportion to the peak amplitude value of each amplified electrical signal.

Claim 4

A circuit as recited in claim 1 adpated to receive a plurality of sound signals at different predetermined frequencies and further comprising a plurality of bandpass filter means responsive to the amplified electrical signals for separating the amplified electrical signals according to the predetermined frequencies of the control sound signals and for feeding the separated amplified electrical signals to separate control channels.

Claim 5

A circuit as recited in claim 3 wherein separate output control signal producing means are provided for each control signal channel, and further including means responsive to the duration of the amplified electrical signal in each channel for preventing the output of control signals from the respective control signal producing means when the amplified electrical signal in the corresponding channel is not of a predetermined time duration.

Claim 6

A circuit as recited in claim 4 further comprising separate detecting circuits in each of the channels, each of the detecting circuits being separately responsive to the amplified electrical signals passed by the respective bandpass filter means for detecting the signals and for producing direct current pulses representative of the amplified electrical signals.

Claim 7

A circuit for discriminating between spurious signals and information signals, said information signals having an amplitude at least as great as a predetermined level and at least a predetermined duration at that amplitude and having at least one predetermined frequency, the spurious signals also including substantially the predetermined frequency but having an inconstant amplitude that drops below the predetermined level within a shorter time than said predetermined duration, said circuit comprising: A. amplifier means for amplifying all of said signals; B. control means responsive to the amplified signals for producing a control signal inversely proportional to the peak amplitude of the amplified signals, said control means being connected to said amplifier to control the gain of the amplifier means; C. means for converting the information signals and the spurious signals into corresponding direct current pulse signals whose durations are representative of the duration of the separate portions of the electrical signals having amplitudes above said predetermined level; D. means for integrating each of the direct current pulse signals with respect to time; and E. means responsive to the integrated direct current pulse signals for producing output control signals representative of each integrated direct current pulse signal whose amplitude exceeds a second predetermined voltage level.

Claim 8

A circuit for discriminating between spurious signals and information signals, said information signals having an amplitude at least as great as a predetermined level and at least a predetermined duration at that amplitude and having at least one predetermined frequency, the spurious signals also including substantially the predetermined frequency but having an inconstant amplitude that drops below the predetermined level within a shorter time than said predetermined duration, said circuit comprising: A. amplifier means for amplifying all of said signals; B. control means responsive to the amplified signals for producing a control signal inversely proportional to the peak amplitude of the amplified signals, said control means being connected to said amplifier to control the gain of the amplifier means; C. means for converting the information signals and the spurious signals into corresponding direct current pulse signals whose durations are representative of the duration of the separate portions of the electrical signals having amplitudes above said predetermined level; D. means for integrating each of the direct current pulse signals with respect to time; and E. means responsive to the integrated direct current pulse signals for producing output control signals representative of each integrated direct current pulse signal whose amplitude exceeds a second predetermined voltage level.

Claim 9

A circuit for discriminating between noise signals and sound signals generated by a transmitter and having at least one predetermined frequency, said circuit comprising: A. an electro-acoustic transducer means for converting the transmitted sound signals into electrical signals; B. variable gain means for amplifying the electrical signals; C. feedback means responsive to the amplified electrical signals for controlling the gain of the variable gain amplifying means, said feedback control means including means for clamping the peak amplitude of the amplified electrical signals at a first predetermined level; D. means for converting the amplified electrical signals into corresponding direct current pulse signals whose durations are representative of the duration of the separate portions of the amplified electrical signals having amplitudes above a second predetermined voltage level below said first predetermined voltage level; E. means for integrating each of the direct current pulse signals with respect to time; and F. means responsive to the integrated direct current pulse signals for producing output control signals representative of each integrated direct current pulse signal whose amplitude exceeds a third predetermined voltage level.

Claim 10

A circuit for discriminating between noise signals and sound signals generated by a transmitter and having at least one predetermined frequency, said circuit comprising: A. an electro-acoustic transducer means for converting the transmitted sound signals into electrical signals; B. variable gain means for amplifying the electrical signals; C. feedback means responsive to the amplified electrical signals for controlling the gain of the variable gain amplifying means, said feedback control means including means for clamping the peak amplitude of the amplified electrical signals at a first predetermined level; D. means for converting the amplified electrical signals into corresponding direct current pulse signals whose durations are representative of the duration of the separate portions of the amplified electrical signals having amplitudes above a second predetermined voltage level below said first predetermined voltage level; E. means for integrating each of the direct current pulse signals with respect to time; and F. means responsive to the integrated direct current pulse signals for producing output control signals representative of each integrated direct current pulse signal whose amplitude exceeds a third predetermined voltage level.