Patent US3740490A successfully refreshed from Google Patents.
US3740490A
Expired / Lapsed
US
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Tone ringer
Assignee: AT&T Inc
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Filing: 1971-01-18
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Granted: 1973-06-19
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Expires: 1991-01-18
Abstract
Abstract A tone ringer circuit for use in a telephone set employs gating means for discriminating between valid ringing signals and unwanted transients, oscillatory generator means for energizing an output tranducer, and power conversion means for deriving ringing power from the input signal. The validity of the ringing signal is determined by measurement of the energy content of a portion of each signal cycle. The basic tone ringer may be modified to permit realization of a distinctive ringing capability.
Inventors
- 👤 D Trimble
- 👤 Alonie R Mc
- 👤 H Sautter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:58
CPC Classifications
H; H04; H04M; H04M19/00; H04M19/02; H04M19/04
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
84 words
A tone ringer circuit comprising, in combination, input terminals for the reception of ringing signals, gating means for distinguishing between valid and invalid ringing signals applied across said input terminals, an electroacoustic transducer for producing an audible output, oscillatory generator means, responsive to said gating means, for actuating said electroacoustic transducer, power conversion means for supplying ringing energy to said oscillatory generator means, and means for preventing the production of an audible output in response to transient voltages generated within said tone ringer circuit.
Claim 2
Dependent Claim
84 words
A tone ringer circuit comprising, in combination, input terminals for the reception of ringing signals, gating means for distinguishing between valid and invalid ringing signals applied across said input terminals, an electroacoustic transducer for producing an audible output, oscillatory generator means, responsive to said gating means, for actuating said electroacoustic transducer, power conversion means for supplying ringing energy to said oscillatory generator means, and means for preventing the production of an audible output in response to transient voltages generated within said tone ringer circuit.
Claim 3
Dependent Claim
59 words
Apparatus in accordance with claim 1 wherein said last named means comprises, first and second transistor switches, said first transistor switch disconnecting said power conversion means from said oscillatory generator means in the presence of said transient voltages, and said second transistor switch disconnecting said electroacoustic transducer from said oscillatory generator means in the presence of said transient voltages.
Claim 4
Dependent Claim
85 words
In a tone ringer, apparatus for distinguishing between valid and invalid ringing signals comprising, in combination, a threshold detector circuit, a limiter circuit, an averaging circuit, and a transistor switch circuit, wherein said ringing signals which exceed a voltage level set by said threshold detector circuit are limited in amplitude by said limiter circuit and applied to said averaging circuit, the output of which is sufficient to actuate said transistor switch circuit only if said ringing signals include preselected characteristics of voltage, frequency and power.
Claim 5
Dependent Claim
85 words
In a tone ringer, apparatus for distinguishing between valid and invalid ringing signals comprising, in combination, a threshold detector circuit, a limiter circuit, an averaging circuit, and a transistor switch circuit, wherein said ringing signals which exceed a voltage level set by said threshold detector circuit are limited in amplitude by said limiter circuit and applied to said averaging circuit, the output of which is sufficient to actuate said transistor switch circuit only if said ringing signals include preselected characteristics of voltage, frequency and power.
Claim 6
Dependent Claim
43 words
Apparatus in accordance with claim 3 wherein said threshold detector circuit comprises a plurality of pairs of Zener diodes, each Zener Diode of said pairs being connected in series circuit relation with the other of said Zener diodes and in opposite polarity therewith.
Claim 7
Dependent Claim
89 words
Apparatus for the production of an audible output in a communications system, comprising, in combination, input means for the reception of actuating signals, gating means responsive only to actuating signals having preselected characteristics, said preselected characteristics including the energy content per cycle of said actuating signal, oscillatory generator means responsively enabled by said gating means, and transducing means for converting electrical oscillations produced by said oscillatory generator means to an audible output, whereby an audible output is produced only in the presence of actuating signals having said preselected characteristics.
Claim 8
Dependent Claim
89 words
Apparatus for the production of an audible output in a communications system, comprising, in combination, input means for the reception of actuating signals, gating means responsive only to actuating signals having preselected characteristics, said preselected characteristics including the energy content per cycle of said actuating signal, oscillatory generator means responsively enabled by said gating means, and transducing means for converting electrical oscillations produced by said oscillatory generator means to an audible output, whereby an audible output is produced only in the presence of actuating signals having said preselected characteristics.
Claim 9
Dependent Claim
82 words
Apparatus in accordance with claim 1 further including, pulse generating means, a source of direct current potential, first switching means for selectively connecting said source of direct current potential directly to said power conversion means, in order to obtain a substantially constant voltage output therefrom, and second switching means for selectively connecting said pulse generating means to said oscillatory generator means, in order to vary periodically the output frequency thereof, thereby enabling production of an audible output that periodically varies in frequency.
Claim 10
Dependent Claim
19 words
Apparatus in accordance with claim 6 wherein said first and second switching means comprise a single externally controllable switch.
Claim 11
Dependent Claim
23 words
Apparatus in accordance with claim 6 wherein said first and second switching means comprise a single transistor switch controlled by said gating means.
Claim 12
Dependent Claim
77 words
Apparatus in accordance with claim 1 further including, pulse generating means, a source of direct current potential, first switching means for selectively connecting said source of direct current potential directly to said power conversion means, in order to obtain a substantially constant voltage output therefrom, and second switching means for selectively connecting said pulse generating means to said gating means, in order to produce periodic actuations thereof, thereby enabling production of audible outputs that are periodically interrupted.
Claim 13
Dependent Claim
19 words
Apparatus in accordance with claim 9 wherein said first and second switching means comprise a single externally controllable switch.
Claim 14
Dependent Claim
23 words
Apparatus in accordance with claim 9 wherein said first and second switching means comprise a single transistor switch controlled by said gating means.
Claim 15
Dependent Claim
78 words
Apparatus in accordance with claim 1 further including, a source of direct current potential, first switching means for connecting said source of direct current potential directly to said power conversion means, in order to obtain a substantially constant output voltage therefrom, and second switching means for selectively connecting said source of direct current potential to said gating means, thereby continuously actuating said gating means, thereby enabling production of audible outputs that are substantially constant in amplitude and frequency.
Claim 16
Dependent Claim
19 words
Apparatus in accordance with claim 12 wherein said first and second switching means comprise a single externally controllable switch.
Claim 17
Dependent Claim
23 words
Apparatus in accordance with claim 12 wherein said first and second switching means comprise a single transistor switch controlled by said gating means.
Claim 18
Dependent Claim
62 words
A tone ringer circuit comprising, in combination, gating means, oscillatory generator means, and electroacoustical transducer means, wherein said electroacoustical transducer means is energized by said oscillatory generator means in response to the application of a valid ringing signal to said gating means, the validity of said ringing signal being determined by measurement of preselected characteristics of its voltage, frequency and energy content.
Claim 19
Dependent Claim
62 words
A tone ringer circuit comprising, in combination, gating means, oscillatory generator means, and electroacoustical transducer means, wherein said electroacoustical transducer means is energized by said oscillatory generator means in response to the application of a valid ringing signal to said gating means, the validity of said ringing signal being determined by measurement of preselected characteristics of its voltage, frequency and energy content.
Claim 20
Dependent Claim
26 words
Apparatus in accordance with claim 15 furtHer including means for preventing the production of an audible output in response to transient voltages generated within said apparatus.
Claim 21
Dependent Claim
26 words
Apparatus in accordance with claim 16 wherein said last named means comprises a transistor switch responsive to said transient voltages for disabling said oscillatory generator means.
Claim 22
Dependent Claim
25 words
Apparatus in accordance with claim 16 wherein said last named means comprises a transistor switch responsive to said transient voltages for disabling said transducing means.
Claim 23
Dependent Claim
101 words
A signalling circuit adapted for connection to a telephone line comprising: a switching circuit including a signalling device; energy storage means; circuit means for coupling said switching circuit and said energy storage means to said telephone line wherein said telephone line applies a unidirectional energizing potential to said switching circuit and said energy storage means; and second circuit means coupling said switching circuit to said telephone line for detecting the presence of ringing signals on said telephone line to enable said switching circuit to pass current pulses through said signalling device from said energy storage means and actuate said signalling device.
Claim 24
Dependent Claim
101 words
A signalling circuit adapted for connection to a telephone line comprising: a switching circuit including a signalling device; energy storage means; circuit means for coupling said switching circuit and said energy storage means to said telephone line wherein said telephone line applies a unidirectional energizing potential to said switching circuit and said energy storage means; and second circuit means coupling said switching circuit to said telephone line for detecting the presence of ringing signals on said telephone line to enable said switching circuit to pass current pulses through said signalling device from said energy storage means and actuate said signalling device.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-18 | 1976-12-18 | 1977-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-18 | 1980-12-18 | 1981-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-18 | 1984-12-18 | 1985-06-19 | $7700.00 | Window Closed / Lapsed |