US5506900A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature compensation for trans-hybrid loss in a miniaturized data access arrangement
Assignee: Silicon Systems Inc
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Filing: 1995-02-27
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Granted: 1996-04-09
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Expires: 2015-02-27
Abstract
Abstract Method and apparatus for temperature compensation of transhybrid loss in a data access arrangement (DAA) is provided. A thermal compensation device is situated in proximity to a thermally sensitive device. If devices which dissipate substantial power cause heating of the thermally sensitive device and change its characteristics, the thermal compensation device is also heated and compensates for the changes. Thus, a DAA that is unaffected by temperature changes and self-heating is provided. The DAA is suitable for use with data communications equipment utilizing echo cancelling circuitry, such as CCITT V.32 and V.32 bis modems. When used with such modems, the present invention avoids the need to perform retraining and equalization during changes in DAA operating temperature.
Inventors
- 👤 Scott N. Fritz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:37
CPC Classifications
H; H04; H04M; H04M11/00; H04M11/06; H04M3/00; H04M3/005
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
93 words
A circuit comprising: a transformer having a first winding, said first winding having a first winding resistance, said first winding resistance having a first temperature coefficient of resistance; a thermocompensating element coupled to said transformer for providing thermal compensation of transhybrid loss; a transmit signal input coupled to said first winding of said transformer for applying a transmit signal to said transformer; and a receive amplifier circuit coupled to said first winding of said transformer, said receive amplifier circuit for outputting a receive signal, said receive signal being independent of said transmit signal.
Claim 2
Dependent Claim
93 words
A circuit comprising: a transformer having a first winding, said first winding having a first winding resistance, said first winding resistance having a first temperature coefficient of resistance; a thermocompensating element coupled to said transformer for providing thermal compensation of transhybrid loss; a transmit signal input coupled to said first winding of said transformer for applying a transmit signal to said transformer; and a receive amplifier circuit coupled to said first winding of said transformer, said receive amplifier circuit for outputting a receive signal, said receive signal being independent of said transmit signal.
Claim 3
Dependent Claim
31 words
The circuit of claim 1 wherein said thermocompensating element comprises a thermistor, said thermistor having a second temperature coefficient of resistance and a thermistor room temperature resistance at a room temperature.
Claim 4
Dependent Claim
13 words
The circuit of claim 2 wherein said circuit comprises a telephone hybrid circuit.
Claim 5
Dependent Claim
34 words
The circuit of claim 3 wherein said receive amplifier circuit has a first input coupled to a first terminal of said transformer and a second input coupled to a second terminal of said transformer.
Claim 6
Dependent Claim
39 words
The circuit of claim 4 wherein said receive amplifier circuit comprises a summing amplifier circuit for amplifying a combination of a first input signal present at said first input and a second input signal present at said second input.
Claim 7
Dependent Claim
18 words
The circuit of claim 2 wherein said thermistor is in series with said first winding of said transformer.
Claim 8
Dependent Claim
34 words
The circuit of claim 6 further comprising a resistor having a second resistance and a third temperature coefficient of resistance approximately equal to zero, wherein said resistor is configured in series with said thermistor.
Claim 9
Dependent Claim
63 words
The circuit of claim 7 further comprising a transmission line coupled to a second winding of said transformer, said second winding having a second winding resistance, wherein ρW=said first temperature coefficient of resistance; RWN=said first winding resistance+said second winding resistance; RL=a characteristic impedance of said transmission line; ρT'=an effective temperature coefficient of the combination of said thermocompensating element and said resistor, and; ##EQU26##
Claim 10
Dependent Claim
40 words
The circuit of claim 8 wherein ρ161=said second temperature coefficient of resistance; R161N=said thermistor room temperature resistance; R16=said second resistance, and; ##EQU27## wherein said thermistor and said resistor cooperatively compensate for thermal changes of said first and second winding resistances.
Claim 11
Dependent Claim
17 words
The circuit of claim 2 wherein said thermistor is mounted on an isothermal line with said transformer.
Claim 12
Dependent Claim
17 words
The circuit of claim 10 wherein said thermistor and said transformer are mounted on a ceramic substrate.
Claim 13
Dependent Claim
18 words
The circuit of claim 10 wherein said thermistor and said transformer are mounted on a fiberglass composite substrate.
Claim 14
Dependent Claim
13 words
The circuit of claim 2 wherein said circuit comprises an ISDN interface circuit.
Claim 15
Dependent Claim
12 words
The circuit of claim 2 wherein said circuit comprises a LAN interface.
Claim 16
Dependent Claim
86 words
A telephone hybrid circuit comprising: a transformer having a first winding and a second winding for isolating a telephone line from user equipment; a hookswitch for selectively coupling said transformer to said telephone line; a receive amplifier coupled to said second winding of said transformer for amplifying a receive signal; a thermistor coupled to said second winding of said transformer for compensating for a thermal dependency of said transformer; a transmit signal input coupled to said second winding of said transformer for providing a transmit signal.
Claim 17
Dependent Claim
86 words
A telephone hybrid circuit comprising: a transformer having a first winding and a second winding for isolating a telephone line from user equipment; a hookswitch for selectively coupling said transformer to said telephone line; a receive amplifier coupled to said second winding of said transformer for amplifying a receive signal; a thermistor coupled to said second winding of said transformer for compensating for a thermal dependency of said transformer; a transmit signal input coupled to said second winding of said transformer for providing a transmit signal.
Claim 18
Dependent Claim
36 words
The circuit of claim 15 further comprising a resistor having a nominal zero temperature coefficient of resistance coupled to said thermistor for matching a thermistor temperature coefficient of resistance to a transformer temperature coefficient of resistance.
Claim 19
Dependent Claim
113 words
A circuit comprising: an isolation transformer having a first winding and a second winding, said first winding having a first winding resistance, said first winding resistance having a first temperature coefficient of resistance, said isolation transformer for providing isolation of DC voltages between said first winding and said second winding; a thermocompensating element coupled to said isolation transformer for providing thermal compensation of transhybrid loss; a capacitor in series with said second winding of said isolation transformer for coupling said second winding of said isolation transformer to a subscriber telephone line; a summing amplifier circuit coupled to said first winding of said isolation transformer for amplifying a signal from said subscriber telephone line.
Claim 20
Dependent Claim
113 words
A circuit comprising: an isolation transformer having a first winding and a second winding, said first winding having a first winding resistance, said first winding resistance having a first temperature coefficient of resistance, said isolation transformer for providing isolation of DC voltages between said first winding and said second winding; a thermocompensating element coupled to said isolation transformer for providing thermal compensation of transhybrid loss; a capacitor in series with said second winding of said isolation transformer for coupling said second winding of said isolation transformer to a subscriber telephone line; a summing amplifier circuit coupled to said first winding of said isolation transformer for amplifying a signal from said subscriber telephone line.
Claim 21
Dependent Claim
31 words
The circuit of claim 17 wherein said thermocompensating element comprises a thermistor, said thermistor having a second temperature coefficient of resistance and a thermistor room temperature resistance at a room temperature.
Claim 22
Dependent Claim
13 words
The circuit of claim 18 wherein said circuit comprises a telephone hybrid circuit.
Claim 23
Dependent Claim
37 words
The circuit of claim 19 further comprising a receive amplifier circuit having a first input coupled to a first terminal of said isolation transformer and a second input coupled to a second terminal of said isolation transformer.
Claim 24
Dependent Claim
39 words
The circuit of claim 20 wherein said receive amplifier circuit comprises a summing amplifier circuit for amplifying a combination of a first input signal present at said first input and a second input signal present at said second input.
Claim 25
Dependent Claim
19 words
The circuit of claim 18 wherein said thermistor is in series with said first winding of said isolation transformer.
Claim 26
Dependent Claim
34 words
The circuit of claim 22 further comprising a resistor having a second resistance and a third temperature coefficient of resistance approximately equal to zero, wherein said resistor is configured in series with said thermistor.
Claim 27
Dependent Claim
64 words
The circuit of claim 23 further comprising a transmission line coupled to said second winding of said isolation transformer, said second winding having a second winding resistance, wherein ρW=said first temperature coefficient of resistance; RWN=said first winding resistance+said second winding resistance; RL=a characteristic impedance of said transmission line; ρT'=an effective temperature coefficient of the combination of said thermocompensating element and said resistor, and; ##EQU28##
Claim 28
Dependent Claim
40 words
The circuit of claim 24 wherein ρ161=said second temperature coefficient of resistance; R161N=said thermistor room temperature resistance; R16=said second resistance, and; ##EQU29## wherein said thermistor and said resistor cooperatively compensate for thermal changes of said first and second winding resistances.
Claim 29
Dependent Claim
18 words
The circuit of claim 18 wherein said thermistor is mounted on an isothermal line with said isolation transformer.
Claim 30
Dependent Claim
18 words
The circuit of claim 26 wherein said thermistor and said isolation transformer are mounted on a ceramic substrate.
Claim 31
Dependent Claim
19 words
The circuit of claim 26 wherein said thermistor and said isolation transformer are mounted on a fiberglass composite substrate.
Claim 32
Dependent Claim
13 words
The circuit of claim 18 wherein said circuit comprises an ISDN interface circuit.
Claim 33
Dependent Claim
12 words
The circuit of claim 18 wherein said circuit comprises a LAN interface.
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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) | 1999-04-09 | 1999-10-09 | 2000-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-09 | 2003-10-09 | 2004-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-09 | 2007-10-09 | 2008-04-09 | $7700.00 | Window Closed / Lapsed |