Electronic tone generator

Claim 2

An audio signal generator for electronically simulating the audio output produced by a mechanical chime and including means in said generator for producing two tones separated by a musical third, each of said two tones comprised of the sum of two frequencies separated by approximately 10 Hz, means for shaping said tones in amplitude to simulate an envelope of successive mechanically struck mechanical chimes at predetermined time intervals, and said generator including means responsive to standard telephone ringing voltage to initiate and power said generator, and wherein the means for said shaping said two tones comprises a ring voltage sense circuit to detect a ringing signal, and a monostable multivibrator responsive to detection of a ringing signal by said ring voltage sense circuit to produce a signal output, a variable gain driver that receives as input the first tone and a signal output of the monostable multivibrator, the operation of said variable gain driver initiated by the output of the monostable multivibrator and producing a combined DC and AC output voltage necessary to drive an audio amplifier and a transducer to simulate a single strike of a gong.

Claim 3

A signal generator as claimed in claim 1, wherein said generator also comprises a second variable gain driver that receives as input the second tone and the output of the ring voltage sense circuit, said second variable gain driver initiated by the output of the ring voltage sense circuit for producing a DC and AC output voltage necessary to drive said audio amplifier and transducer to simulate another single strike of a gong, said audio amplifier combining the outputs of said two variable gain drivers to drive said transducer, and said audio amplifier having the properties of low power requirements for low distortion amplification.

Claim 4

A tone generator adapted to respond to a validated input telephone ringing signal of predetermined duration, said generator comprising a plurality of oscillators operatively responsive to the validated input signal to produce respective output signals of predetermined different audio frequencies, a first attenuating amplifying means coupled to receive output signals from a first of said oscillators, a second attenuating amplifying means coupled to receive output signals from a second of said oscillators, said first amplifying means operative after the receipt of a validated input signal for transmitting a tone signal based on its received signals and for gradually attenuating said tone signal to an attenuated level, means for delaying the start of an output tone signal from said second amplifying means until the output tone signal from said first amplifying means is at a partially attenuated level whereby the output tone signals from said amplifying means overlap for a predetermined time period, said second amplifying means operative in a attenuating manner to attenuate its output tone signal, and an output audio device receptive of said output tone signals for producing chimelike audible signals therefrom.

Claim 5

A tone generator adapted to respond to a validated input telephone ringing signal of predetermined duration, said generator comprising a plurality of oscillators operatively responsive to the validated input signal to produce respective output signals of predetermined different audio frequencies, a first attenuating amplifying means coupled to receive output signals from a first of said oscillators, a second attenuating amplifying means coupled to receive output signals from a second of said oscillators, said first amplifying means operative after the receipt of a validated input signal for transmitting a tone signal based on its received signals and for gradually attenuating said tone signal to an attenuated level, means for delaying the start of an output tone signal from said second amplifying means until the output tone signal from said first amplifying means is at a partially attenuated level whereby the output tone signals from said amplifying means overlap for a predetermined time period, said second amplifying means operative in a attenuating manner to attenuate its output tone signal, and an output audio device receptive of said output tone signals for producing chimelike audible signals therefrom.

Claim 6

A tone generator as claimed in claim 3, wherein the oscillators of said plurality are paired, and in which there are means for summing the output signals of each pair, said summing means being coupled to the respective amplifying means, and each said amplifying means comprises a variable gain driver.

Claim 7

A tone generator as claimed in claim 4, wherein said delaying means are responsive to the end of the duration of said input signal for initiating the output tone signal from said second amplifying means.

Claim 8

An electronic tone generator for simulating the sound of a two-tone mechanical chime in response to a telephone ringing signal, and comprising a first pair of oscillators, each productive of a separate output frequency spaced from one another about a first basic frequency, a second pair of oscillators each productive of a separate output frequency spaced from one another about a second basic frequency, said first and second basIc frequencies being spaced apart by a predetermined frequency range, means responsive to a valid ringing signal for initiating production of output frequencies by said oscillators, means for summing amplitudes from said first pair of oscillators, a first variable gain driver coupled to the output of said summing means, further summing means coupled to the output of said second pair of oscillators, and a second variable gain driver coupled to the output of said further summing means, means for initiating an output signal from said first driver after the start of said ringing signal, means for delaying an output signal from said second driver to overlap with the output signal from said first driver.

Claim 9

An electronic tone generator for simulating the sound of a two-tone mechanical chime in response to a telephone ringing signal, and comprising a first pair of oscillators, each productive of a separate output frequency spaced from one another about a first basic frequency, a second pair of oscillators each productive of a separate output frequency spaced from one another about a second basic frequency, said first and second basIc frequencies being spaced apart by a predetermined frequency range, means responsive to a valid ringing signal for initiating production of output frequencies by said oscillators, means for summing amplitudes from said first pair of oscillators, a first variable gain driver coupled to the output of said summing means, further summing means coupled to the output of said second pair of oscillators, and a second variable gain driver coupled to the output of said further summing means, means for initiating an output signal from said first driver after the start of said ringing signal, means for delaying an output signal from said second driver to overlap with the output signal from said first driver.

Claim 10

An electronic tone generator as claimed in claim 6, wherein each variable gain driver attenuates the output from the summing means gradually from an original high level to an attenuated low level.

Claim 11

An electronic tone generator for simulating the sound of a mechanical chime in response to a telephone ringing signal, said generator comprising, in combination: a plurality of oscillators, each oscillator providing a substantially constant output signal having a frequency different from the frequency of the other oscillators; first means for summing the output signals of a first pair of said oscillators, second means for summing the output signals of a second pair of said oscillators, first amplifying means operative after receipt of said ringing signal to emit an amplified signal based on said summed output of said first pair of oscillators during a first given time period wherein the amplitude of said summed signal emitted by said amplifying means decays from an amplified level to an attenuated level during said first given time period, second amplifying means operatively responsive to the end of said ringing signal to emit an amplified signal based on the summed output of said second pair of oscillators during a second given time period wherein the amplitude of said summed signal emitted by said second amplifying means decays from a first level to a second level during said second given time period, and wherein said first and second given time periods overlap for a further time period, and an output transducer receptive of the output signals from said amplifying means to produce a two-tone chime-like audio output.

Claim 12

An electronic tone generator for simulating the sound of a mechanical chime in response to a telephone ringing signal, said generator comprising, in combination: a plurality of oscillators, each oscillator providing a substantially constant output signal having a frequency different from the frequency of the other oscillators; first means for summing the output signals of a first pair of said oscillators, second means for summing the output signals of a second pair of said oscillators, first amplifying means operative after receipt of said ringing signal to emit an amplified signal based on said summed output of said first pair of oscillators during a first given time period wherein the amplitude of said summed signal emitted by said amplifying means decays from an amplified level to an attenuated level during said first given time period, second amplifying means operatively responsive to the end of said ringing signal to emit an amplified signal based on the summed output of said second pair of oscillators during a second given time period wherein the amplitude of said summed signal emitted by said second amplifying means decays from a first level to a second level during said second given time period, and wherein said first and second given time periods overlap for a further time period, and an output transducer receptive of the output signals from said amplifying means to produce a two-tone chime-like audio output.