Patent US3735203A successfully refreshed from Google Patents.
US3735203A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ve circuit
Assignee: Pioneer Corp
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Filing: 1971-11-16
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Granted: 1973-05-22
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Expires: 1991-11-16
Abstract
Abstract A protective circuit for protecting an output circuit and a load circuit of a signal amplifier from abnormal conditions, and including a differential amplifier for detecting the abnormal conditions, and a sensitivity control circuit for reducing the amplification factor of the differential amplifier for the input signal so that the output signal of the signal amplifier is clipped.
Inventors
- 👤 S Fujie
- 👤 Y Saeki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:42
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/52; H03F1/56
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
193 words
A protective circuit for protecting an output stage of an input signal amplifier comprising: a. a normally balanced differential amplifier having a first input coupled to the input of, and a secoNd input coupled to the output of, said signal amplifier, said differential amplifier being responsive to an abnormal condition of said signal amplifier to go into an unbalanced state to produce a control signal at its output, b. normally unoperated switching means connected to the output of said differential amplifier and operative to protect the output stage of said signal amplifier from abnormal conditions, said switching means being operated by said control signal when said differential amplifier goes into an unbalanced state, c. a sensitivity control circuit for reducing the amplification factor of said differential amplifier for the input signal of said signal amplifier when the output signal of said signal amplifier is clipped, and d. an attenuation circuit having an input connected to said output of said signal amplifier and having an output connected to said second input of said differential amplifier, said attenuation circuit having an attenuation factor of the same magnitude as the amplification factor of said signal amplifier.
Claim 2
Dependent Claim
193 words
A protective circuit for protecting an output stage of an input signal amplifier comprising: a. a normally balanced differential amplifier having a first input coupled to the input of, and a secoNd input coupled to the output of, said signal amplifier, said differential amplifier being responsive to an abnormal condition of said signal amplifier to go into an unbalanced state to produce a control signal at its output, b. normally unoperated switching means connected to the output of said differential amplifier and operative to protect the output stage of said signal amplifier from abnormal conditions, said switching means being operated by said control signal when said differential amplifier goes into an unbalanced state, c. a sensitivity control circuit for reducing the amplification factor of said differential amplifier for the input signal of said signal amplifier when the output signal of said signal amplifier is clipped, and d. an attenuation circuit having an input connected to said output of said signal amplifier and having an output connected to said second input of said differential amplifier, said attenuation circuit having an attenuation factor of the same magnitude as the amplification factor of said signal amplifier.
Claim 3
Dependent Claim
27 words
A protective circuit as set forth in claim 1, wherein said switching means comprises a switching having a switch contact in the output of said signal amplifier.
Claim 4
Dependent Claim
17 words
A protective circuit as set forth in claim 1, wherein said signal amplifier is an output-condenser-less amplifier.
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) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |