US3613022A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Branching circuit for composite electrical signals
Assignee: International Standard Electric Corp
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Filing: 1969-02-03
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Granted: 1971-10-12
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Expires: 1989-02-03
Abstract
Abstract Branching networks comprise two filters having complementary characteristics e.g. a LP and a HP network. Only one filter network is used in the proposed arrangement. The complementary network is replaced by an active circuit using a unilateral phase splitter and a differential amplifier at the output of which only those signals appear which are blocked by the filter network. The main object of the invention is to reduce the number of coils and capacitors required. These are expensive and are not suited to printed circuit technique.
Inventors
- 👤 Lionel J White
- 👤 Anthony Drake
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:38
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/34; H04; H04R; H04R3/00; H04R3/12; H04R3/14
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
126 words
A branching circuit for composite audiofrequency signals comprising a unilateral phase-splitting circuit connected to a source of said signal, a filter network and a differential amplifier, a first output signal from the phase-splitting circuit being applied to the input of the filter network and to an input of the differential amplifier, the second output from the phasesplitting circuit, of opposite phase to the first, being applied to the other input of the differential amplifier, the branching circuit providing a first branched signal at the output terminals of the filter network for signal components falling within the pass band of said filter network and a second branched signal at the output of the differential amplifier for signal components falling within the stop band of the filter network.
Claim 2
Dependent Claim
126 words
A branching circuit for composite audiofrequency signals comprising a unilateral phase-splitting circuit connected to a source of said signal, a filter network and a differential amplifier, a first output signal from the phase-splitting circuit being applied to the input of the filter network and to an input of the differential amplifier, the second output from the phasesplitting circuit, of opposite phase to the first, being applied to the other input of the differential amplifier, the branching circuit providing a first branched signal at the output terminals of the filter network for signal components falling within the pass band of said filter network and a second branched signal at the output of the differential amplifier for signal components falling within the stop band of the filter network.
Claim 3
Dependent Claim
67 words
A circuit as claimed in claim 1 in which the phase-splitting circuit comprises a single transistor circuit to the base of which the composite input signal is applied and the two antiphase output signals are derived from the emitter and collector circuits respectively, the output which is applied to the filter network and to the first input of the differential amplifier being taken from the collector circuit.
Claim 4
Dependent Claim
60 words
A circuit as claimed in claim 2 in which the differential amplifier comprises two transistors to the base electrodes of which the two input signals are applied, the output signal being obtained from a load resistor which is common to the collector circuits of both transistors, the emitter circuit of each transistor including a separate resistor to provide negative feedback.
Claim 5
Dependent Claim
61 words
A circuit as claimed in claim 3 in which the signals applied to the two inputs of the differential amplifier are of equal magnitude and of opposite phase when their frequency falls within the pass band of the filter, but are unequal in magnitude and/or not in opposite phase when their frequency falls within the stop band of the filter network.
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) | 1974-10-11 | 1975-04-12 | 1975-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-11 | 1979-04-12 | 1979-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-11 | 1983-04-12 | 1983-10-12 | $7700.00 | Window Closed / Lapsed |