Remote control system

Claim 2

A remote control system for initiating a control function in an apparatus from a remote location, comprising: a remotely located transmitter for generating a wave signal at a predetermined discrete frequency; receiving means, for intercepting said wave signal, comprising a multivibrator for generating constant-amplitude pulses of uniform predetermined duration at a repetition rate corresponding to the frequency of said wave signal, and a digital-to-analog converter for developing a control signal from said pulses having a predetermined voltage level during reception of wave signals at said predetermined frequency; control signal recognition means for producing a control effect only when said control signal is at said predetermined voltage level; and utilization means responsive to said control effect for performing said control function during reception of wave signals at said predetermined frequency.

Claim 3

A remote control system as described in claim 1 wherein said control signal developed by said receiving means has a nominal voltage level in the absence of an intercepted wave signal and is progressively variable upon initial receipt of an intercepted wave signal, and wherein are further provided inhibiting means for preventing said control signal recognition means from producing a control effect while said control signal is progressively variable.

Claim 4

A remote control system as described in claim 1 wherein said control signal recognition means comprise a source of reference potential at said predetermined voltage level, and voltage comparator means for comparing said control voltage with said reference voltage level and developing said control effect when said voltage levels agree.

Claim 5

A remote control system as described in claim 3 wherein said wave signal lies within a frequency band having a predetermined upper limit and wherein said multivibrator is a monostable multivibrator producing pulses of uniform predetermined duration such that above said upper frequency limit said pulses overlap to present a constant non-pulsating signal to said digital-to-analog converter.

Claim 6

A remote control system as described in claim 4 wherein said control signal recognition means respond only to control signals within a predetermined voltage range, and wherein said digital-to-analog converter develops a control signal outside said range in response to a constant non-pulsating signal from said monostable multivibrator.

Claim 7

A remote control system as described in claim 5 wherein the control signal developed by said digital-to-analog converter: proGressively assumes a predetermined voltage level below said predetermined voltage range in the absence of pulses from said multivibrator; increases within said predetermined range with increases in said pulse repetition rate; and rapidly falls below said range in response to said constant non-pulsating signal.

Claim 8

A remote control system as described in claim 6 wherein said wave signal is an ultrasonic pressure wave.

Claim 9

A remote control system for performing a plurality of control functions in a television receiver or the like from a remote location, comprising: a remotely located transmitter for generating a wave signal at one of a plurality of discrete frequencies each of which corresponds to an assigned one of said control functions; receiving means for intercepting and converting said wave signals to a series of pulses of predetermined uniform width and amplitude, and having a repetition rate corresponding to the frequency of said intercepted wave signals; means for developing a control signal, having a voltage level representative of the repetition rate of said constant-amplitude, constant-width pulses; at least one control signal recognition means including a voltage comparator for producing a control effect when said control signal is at a predetermined voltage level; and utilization means for performing an assigned one of said control functions in response to said control effect.

Claim 10

A remote control system for performing a plurality of control functions in a television receiver or the like from a remote location, comprising: a remotely located transmitter for generating a wave signal at one of a plurality of discrete frequencies each of which corresponds to an assigned one of said control functions; receiving means for intercepting and converting said wave signals to a series of pulses of predetermined uniform width and amplitude, and having a repetition rate corresponding to the frequency of said intercepted wave signals; means for developing a control signal, having a voltage level representative of the repetition rate of said constant-amplitude, constant-width pulses; at least one control signal recognition means including a voltage comparator for producing a control effect when said control signal is at a predetermined voltage level; and utilization means for performing an assigned one of said control functions in response to said control effect.

Claim 11

A remote control system as described in claim 8 wherein the voltage level of said control signal developed by said receiving means has a nominal voltage level in the absence of an intercepted wave signal and is progressively variable upon initial receipt of an intercepted wave signal, and wherein are further provided inhibiting means for preventing said first and second control signal recognition means from producing a control effect while said control signal is progressively variable.