Abstract An automatic gain control circuit is disclosed in which the emitter electrode of a transistor for amplification is grounded through the collector-emitter path of a transistor for control, the collector electrode of the first mentioned transistor is connected to a voltage source through a series connection of a tuning circuit and a resistor, and the connection point between the tuning circuit and resistor is grounded through a capacitor, and in which the connection point between the tuning circuit and resistor is connected through a series connection of resistor and a capacitor to the base electrode of the second mentioned transistor and a detected signal is applied to a low-pass filter to produce an AGC voltage which is applied to the base electrode of the second mentioned transistor.
In an AGC circuit in which an emitter electrode of a transistor for amplification is grounded through a collectoremitter path of a transistor for control, the collector electrode of the first mentioned transistor is connected to a voltage source through a series connection of a tuning circuit and a resistor, and the connection point between the tuning circuit and resistor is grounded through a capacitor and a detected signal is applied to a low-pass filter, said AGC circuit comprising: a. a series connection of a resistor and a capacitor connected between said connection point and the base electrode of said second mentioned transistor, an AGC voltage produced by said low-pass filter being applied to the base electrode of said second mentioned transistor.
Claim 2
Dependent Claim
122 words
In an AGC circuit in which an emitter electrode of a transistor for amplification is grounded through a collectoremitter path of a transistor for control, the collector electrode of the first mentioned transistor is connected to a voltage source through a series connection of a tuning circuit and a resistor, and the connection point between the tuning circuit and resistor is grounded through a capacitor and a detected signal is applied to a low-pass filter, said AGC circuit comprising: a. a series connection of a resistor and a capacitor connected between said connection point and the base electrode of said second mentioned transistor, an AGC voltage produced by said low-pass filter being applied to the base electrode of said second mentioned transistor.
Claim 3
Dependent Claim
25 words
An AGC circuit according to claim 1 further comprising a series connection of a diode and a capacitor connected in parallel to said low-pass filter.
Claim 4
Dependent Claim
22 words
An AGC circuit according to claim 2, in which a connection point between said diode and capacitor is grounded through a resistor.