Patent US3816760A successfully refreshed from Google Patents.
US3816760A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable level noise barrier circuit responsive to a bipolar input and having variable bipolar hysteresis and having a bipolar output
Assignee: Dahl G Co Inc
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Filing: 1971-10-26
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Granted: 1974-06-11
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Expires: 1991-10-26
Abstract
Abstract A noise barrier circuit employs an amplifier in a bridge circuit having positive and negative feedback paths in two of the bridge legs. When the bridge is balanced, the feedback paths mutually cancel, and the circuit operates as an open-loop amplifier. When the bridge is unbalanced, a hysteresis effect is produced by the difference in feedback effects, and unwanted signals within the bipolar hysteresis levels are not passed to the output of the noise barrier circuit. The hysteresis effect is adjustable to desired levels by the degree of bridge imbalance. A modification permits unbalancing the bridge functionally by varying the amount of feedback in one of the feedback paths rather than varying a bridge leg resistance, thereby providing for improved d-c stability. The noise barrier circuits operate upon bipolar inputs and produce a bipolar output.
Inventors
- 👤 R Slawson
- 👤 A Nazareth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:52
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/01; H03K3/013; H03K3/02; H03K3/023; H03K3/0233; H03K3/02337
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
200 words
A noise barrier circuit having a pair of input terminals thereto and having an output terminal thereof and having a differential amplifier with a pair of differential inputs and having a first pair of resistances connected between said input terminals to said noise barrier circuit and respective differential inputs of said differential amplifier and having a second pair of resistive feedback paths connected from the output of said differential amplifier to respective said differential inputs of said differential amplifier and with said output of said differential amplifier forming said output of said noise barrier circuit, said resistances and said feedback paths forming a bridge configuration, means for balancing and unbalancing said bridge configuration, so that in a first condition of said noise barrier circuit said amplifier is in a balanced bridge configuration with said first pair of resistances and said second pair of resistive feedback paths whereby said noise barrier circuit acts as an open-loop amplifier with high gain and in a second condition said bridge configuration is unbalanced by a predetermined amount thereby introducing a bipolar hysteresis effect causing said noise barrier circuit to be switched only by bipolar input signals exceeding the levels determined by said hysteresis effect.
Claim 2
Dependent Claim
200 words
A noise barrier circuit having a pair of input terminals thereto and having an output terminal thereof and having a differential amplifier with a pair of differential inputs and having a first pair of resistances connected between said input terminals to said noise barrier circuit and respective differential inputs of said differential amplifier and having a second pair of resistive feedback paths connected from the output of said differential amplifier to respective said differential inputs of said differential amplifier and with said output of said differential amplifier forming said output of said noise barrier circuit, said resistances and said feedback paths forming a bridge configuration, means for balancing and unbalancing said bridge configuration, so that in a first condition of said noise barrier circuit said amplifier is in a balanced bridge configuration with said first pair of resistances and said second pair of resistive feedback paths whereby said noise barrier circuit acts as an open-loop amplifier with high gain and in a second condition said bridge configuration is unbalanced by a predetermined amount thereby introducing a bipolar hysteresis effect causing said noise barrier circuit to be switched only by bipolar input signals exceeding the levels determined by said hysteresis effect.
Claim 3
Dependent Claim
26 words
The noise barrier circuit of claim 1 with a pair of input common reference resistors connected from respective said input terminals to a circuit common reference.
Claim 4
Dependent Claim
20 words
The noise barrier circuit of claim 1 with one of said input terminals connected directly to a circuit common reference.
Claim 5
Dependent Claim
34 words
The noise barrier circuit of claim 1 with said means for balancing and unbalancing said bridge configuration consisting of a potentiometer adapted to obtain a desired degree of resistive imbalance in said bridge configuration.
Claim 6
Dependent Claim
82 words
The noise barrier circuit of claim 1 with said bridge being substantially in resistive balance under all conditions and with bridge operational imbalance for producing said hysteresis effect being obtained to a desired degree by said means for balancing and unbalancing said bridge configuration to vary the relative amounts of feedback as between said pair of feedback paths whereby a differential potential derived through said feedback paths is impressed between said differential inputs of said amplifier in the imbalanced condition of operation.
Claim 7
Dependent Claim
15 words
The noise barrier circuit of claim 5 with said amplifier being a stock integrated circuit.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |