US3828266A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal control circuit
Assignee: Sony Corp
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Filing: 1973-02-28
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Granted: 1974-08-06
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Expires: 1993-02-28
Abstract
Abstract A signal control circuit which includes an amplifying transistor connected to an input circuit to receive an input signal. A constant reference bias voltage is produced across a diode connected to the input circuit and signals are connected from the input circuit to the transistor by a resistor. A controllable impedance is connected at a point between the resistor and the transistor so that by controlling the impedance the current gain of the amplifier is linearly controlled over a wide range.
Inventors
- 👤 T Okada
- 👤 Y Ogawaae
- 👤 M Takeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:15
CPC Classifications
H; H03; H03G; H03G1/00; H03G1/0005; H03G1/0017; H03G1/0023; H03G3/00; H03G3/20; H03G3/30; H03G3/3005; H03G3/301; H03G3/3015; H04; H04N; H04N5/00; H04N5/76; H04N5/78; H04N5/782; H04N5/783
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
106 words
A signal control circuit comprising: an amplifying transistor comprising input and output sections for amplifying an input signal reference voltage prouducing means including diode means for providing a constant biasing voltage for said amplifying transistor, said constant biasing voltage being independent of the input signal; resistive means connected between said reference voltage producing means and said input section of said amplifying transistor; and control means responsive to a control signal and connected to a point between said resistive means and said input section to control the current through said resistive means, whereby the gain of said amplifying transistor will be controlled in accordance with said current.
Claim 2
Dependent Claim
106 words
A signal control circuit comprising: an amplifying transistor comprising input and output sections for amplifying an input signal reference voltage prouducing means including diode means for providing a constant biasing voltage for said amplifying transistor, said constant biasing voltage being independent of the input signal; resistive means connected between said reference voltage producing means and said input section of said amplifying transistor; and control means responsive to a control signal and connected to a point between said resistive means and said input section to control the current through said resistive means, whereby the gain of said amplifying transistor will be controlled in accordance with said current.
Claim 3
Dependent Claim
25 words
The signal control circuit of claim 1 in which said reference voltage producing means comprises a transistor having its base and collector directly connected together.
Claim 4
Dependent Claim
56 words
The signal control circuit of claim 1 in which said control means comprises: a second transistor having its emitter-collector circuit connected across said input section; a source of control current; rectifying means connected between said source of control current and the base of said second transistor; and a resistor connected in series with said rectifying means.
Claim 5
Dependent Claim
28 words
The signal control circuit of claim 3 in which said rectifying means and said resistor are connected in series across the base-emitter input circuit of said second transistor.
Claim 6
Dependent Claim
62 words
The signal control circuit of claim 3 comprising, in addition: separate means connecting said source of control current to said reference voltage producing means to supply to said reference voltage producing means a current that varies with the amplification of said amplifying transistor to maintain the sianal-to-noise ratio of said signal control circuit substantially constant for different levels of said control current.
Claim 7
Dependent Claim
95 words
The signal control circuit of claim 3 compRising, in addition: a load impedance connected to said output section; a third transistor having its emitter-collector circuit connected in series with said load impedance; and a fourth transistor having an input connected to said source of control current to be controlled thereby and having an output circuit connected to said third transistor to control the impedance of said third transistor inversely with the current through said load impedance, whereby the voltage at the collector of said amplifying transistor is substantially independent of variations in said control current.
Claim 8
Dependent Claim
125 words
The signal control circuit of claim 3 comprising, in addition: a load impedance connected to said output section; a third transistor having its emitter-collector circuit connected in series with said load impedance and in parallel with said output section of said amplifying transistor; and said source of control current comprising a source of control voltage and a resistor connected in series therewith, the base of said third transistor being connected to said source of control voltage to be controlled thereby, whereby a change in the magnitude of said control voltage will produce opposite changes in the current drawn through the load impedance by said amplifying transistor and said third transistor to maintain the DC level across said amplifying transistor and said third transistor substantially constant.
Claim 9
Dependent Claim
57 words
The signal control circuit of claim 3 comprising, in addition, a third transistor connected in series with said reference voltage producing means to control the current supplied thereto, said source of control current comprising a source of control voltage and impedance means connected thereto, said third transistor having a base connected to said source of control voltage.
Claim 10
Dependent Claim
46 words
The signal control circuit of claim 8 in which said impedance means connected to said source of control voltage comprises a transistor having a base connected to said source of control voltage and an emitter-collector circuit connected in series with the base of said second transistor.
Claim 11
Dependent Claim
62 words
The signal control circuit of claim 8 comprising, in addition, a compensating current carrying resistor connecting the emitter of said third transistor to said reference voltage producing means and an additional resistor connecting said emitter of said third transistor to the base of said second transistor to supply current thereto to control the current through the emitter-collector circuit of said second transistor.
Claim 12
Dependent Claim
134 words
The signal control circuit of claim 10 comprising, in addition: a load impedance connected to said output section of said amplifying transistor; a further resistor connected in series between said emitter of said third transistor and said additional resistor; a fourth transistor having a base connected to the common connection of said further resistor and said additional resistor to be energized by the voltage at said common connection; a load resistor connected in series with the collector of said fourth transistor; and a fifth transistor having a base connected to the collector of said fourth transistor to be controlled thereby and having an emitter-collector circuit connected in series with said load impedance to control the current through said load impedance to maintain the voltage across said output section of said amplifying transistor substantially constant.
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) | 1977-08-05 | 1978-02-04 | 1978-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-05 | 1982-02-04 | 1982-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-05 | 1986-02-04 | 1986-08-06 | $7700.00 | Window Closed / Lapsed |