US4879746A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Voice communication link interface apparatus
Assignee: Plantronics Inc
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Filing: 1987-12-30
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Granted: 1989-11-07
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Expires: 2007-12-30
Abstract
Abstract Apparatus is provided for interfacing a voice communication instrument, e.g. headset, to a communication link, e.g. a telephone line. The interface includes a transmit channel having amplification, frequency shaping and voice switching to suppress background noise. The interface includes a receive channel having compression limiting as a function of the received signal amplitude and frequency. The interface further includes a power-down circuit and a low battery indicator.
Inventors
- 👤 Robert F. Young
- 👤 Vladimir Kraz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:30
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/60; H04M1/6025; Y; Y02; Y02D; Y02D30/00; Y02D30/70
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
112 words
Apparatus for interfacing a two-way voice communication instrument to a communication link, comprising: a transmit signal channel to provide an electrical voice signal to the communication link; and a receive signal channel to provide a received electrical voice signal to the communication instrument, the receive signal channel including a circuit providing compression limiting to the received electrical voice signal as a function of the frequency and amplitude of the received electrical voice signal and a volume control circuit programmable to a preset gain within the total range of gain adjustment, said volume control providing an increase in volume at a first rate and a reduction in volume at a second, faster rate.
Claim 2
Dependent Claim
112 words
Apparatus for interfacing a two-way voice communication instrument to a communication link, comprising: a transmit signal channel to provide an electrical voice signal to the communication link; and a receive signal channel to provide a received electrical voice signal to the communication instrument, the receive signal channel including a circuit providing compression limiting to the received electrical voice signal as a function of the frequency and amplitude of the received electrical voice signal and a volume control circuit programmable to a preset gain within the total range of gain adjustment, said volume control providing an increase in volume at a first rate and a reduction in volume at a second, faster rate.
Claim 3
Dependent Claim
99 words
Apparatus for interfacing a two-way voice communication instrument to a communication link, comprising: a transmit signal channel to provide an electrical voice signal to the communication link; a receive signal channel to provide a received electrical voice signal to the communication instrument, the receive signal channel including a circuit providing compression limiting to the received electrical voice signal as a function of the frequency and amplitude of the received electrical voice signal; and a low voltage indicator to generate an external indication when the voltage level of a power source coupled to the apparatus decreases below a predetermined level.
Claim 4
Dependent Claim
99 words
Apparatus for interfacing a two-way voice communication instrument to a communication link, comprising: a transmit signal channel to provide an electrical voice signal to the communication link; a receive signal channel to provide a received electrical voice signal to the communication instrument, the receive signal channel including a circuit providing compression limiting to the received electrical voice signal as a function of the frequency and amplitude of the received electrical voice signal; and a low voltage indicator to generate an external indication when the voltage level of a power source coupled to the apparatus decreases below a predetermined level.
Claim 5
Dependent Claim
20 words
The apparatus of claim 2 wherein the low voltage indicator includes means for injecting tone-burst into the receive signal channel.
Claim 6
Dependent Claim
172 words
Apparatus for interfacing a two-way voice communication instrument to a communication link, comprising: a transmit signal channel to provide an electrical voice signal to the communication link; and a receive signal channel to provide a received electrical voice signal to the communication instrument, the receive signal channel including a variable attenuator comprising an operational amplifier having a gain control resistor network programmable by a binary control input; a threshold detector including a high-pass filter receiving the output signal of the attenuator, and a comparator having a first input coupled to the filter output and a second input coupled to a preselected voltage level, the output of the comparator providing a binary output signal; a selector circuit receiving first and second clocking signals, the selector circuit selecting one of the clocking signals based upon the binary output signal of the comparator; and an up/down counter for receiving the selected clocking signal to change a count value, the counter providing the binary control input to program the gain control resistor network of the attenuator.
Claim 7
Dependent Claim
172 words
Apparatus for interfacing a two-way voice communication instrument to a communication link, comprising: a transmit signal channel to provide an electrical voice signal to the communication link; and a receive signal channel to provide a received electrical voice signal to the communication instrument, the receive signal channel including a variable attenuator comprising an operational amplifier having a gain control resistor network programmable by a binary control input; a threshold detector including a high-pass filter receiving the output signal of the attenuator, and a comparator having a first input coupled to the filter output and a second input coupled to a preselected voltage level, the output of the comparator providing a binary output signal; a selector circuit receiving first and second clocking signals, the selector circuit selecting one of the clocking signals based upon the binary output signal of the comparator; and an up/down counter for receiving the selected clocking signal to change a count value, the counter providing the binary control input to program the gain control resistor network of the attenuator.
Claim 8
Dependent Claim
55 words
The apparatus of claim 4 further comprising a clock generator producing the first and second clocking signals, the clock generator producing the first clocking signal to have a frequency different from the frequency of the second clocking signal to cause the counter to increment at a first rate and to decrement at a second rate.
Claim 9
Dependent Claim
114 words
Apparatus for interfacing a two-way voice communication instrument to a communication link, comprising: a transmit signal channel to provide an electrical voice signal to the communication link; a receive signal channel to provide a received electrical voice signal to the communication instrument, the receive signal channel including a circuit providing compression limiting to the received electrical voice signal as a function of the frequency and amplitude of the received electrical voice signal; and a power-down circuit to lower power consumption when no signal is present and to restore full function when a signal appears, said power-down circuit including a timer to produce a power-down control signal and a counter to produce a reset signal.
Claim 10
Dependent Claim
114 words
Apparatus for interfacing a two-way voice communication instrument to a communication link, comprising: a transmit signal channel to provide an electrical voice signal to the communication link; a receive signal channel to provide a received electrical voice signal to the communication instrument, the receive signal channel including a circuit providing compression limiting to the received electrical voice signal as a function of the frequency and amplitude of the received electrical voice signal; and a power-down circuit to lower power consumption when no signal is present and to restore full function when a signal appears, said power-down circuit including a timer to produce a power-down control signal and a counter to produce a reset signal.
References Cited (Backward Citations)
US3562791A
Cited
GB1318054A
Cited
GB1385493A
Cited
US3725585A
Cited
US3969680A
Cited
GB1546672A
Cited
GB1553277A
Cited
US4012596A
Cited
GB1550721A
Cited
US4457014A
Cited
US4536888A
Cited
US4712231A
Cited
US4644579A
Cited
US4641339A
Cited
US4718099A
Cited
US4718099B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-11-06 | 1993-05-08 | 1993-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-06 | 1997-05-08 | 1997-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-06 | 2001-05-08 | 2001-11-07 | $7700.00 | Window Closed / Lapsed |