Af amplifier having constant current consumption

Claim 2

An amplifier circuit providing substantially constant current consumption comprising: a source of direct operating voltage having first and second terminals; a source of signals to be amplified; at least first and second transistors having collector-emitter paths series coupled between said first and second terminals of said source of voltage; utilization means coupled in parallel across said first transistor; means biasing said second transistor for providing a substantially constant current flow therein, said biasing means including a direct current impedance series connected between said first terminal of said source of voltage and said first transistor; a third transistor having a main conduction path series coupled between the junction of said impedance and said first transistor and at least one resistor connected to said second terminal of said voltage source, said second transistor having a control electrode connected to said main conductor path of said third transistor, said third transistor having a control electrode coupled to a point of reference potential for enabling said third transistor to alter the bias of said second transistor for maintaining said current substantially constant; and means for coupling said source of signals to said first transistor for causing current variations in said first transistor corresponding to said signals, said first transistor current variations producing substantially equal and opposite current variations corresponding to said signals in said utilization means.

Claim 3

An amplifier according to claim 1 wherein: temperature responsive means are coupled between said first terminal of said source of voltage and said point of reference potential.

Claim 4

An audio amplifier according to claim 2 wherein: said temperature responsive means comprises at least one semiconductor junction.

Claim 5

In a television receiver wherein auxiliary operating voltages are derived from a deflection circuit of said receiver, an audio amplifier having substantially constant current consumption comprising: a source of direct voltage having first and second terminals; a source of audio signals to be amplified; first and second transistors, each having input, output and common electrodes, said common and output electrodes of said first and second transistors being series connected between said first and second terminals of said source of voltage; utilization means coupled in parallel across said first transistor; biasing means coupled to the input electrode of said second transistor for enabling said second transistor to establish a substantially constant current flow therein, said biasing means including a direct current impedance series connected between said first terminal of said source of voltage and said first transistor; a third transistor having a main conduction path series coupled between the junction of said impedance and said first transistor and at least one resistor connected to a second terminal of said voltage source, said second transistor having a control electrode connected to said main conductor path of said third transistor, said third transistor having a control electrode coupled to a point of reference potentiaL for enabling said third transistor to alter the bias of said second transistor for maintaining said current substantially constant; and means for coupling said source of audio signals to said input electrode of said first transistor for causing voltage variations between said output and common electrodes of said first transistor corresponding to said audio signals, said first transistor voltage variations producing output signal variations in said utilization means.

Claim 6

In a television receiver wherein auxiliary operating voltages are derived from a deflection circuit of said receiver, an audio amplifier having substantially constant current consumption comprising: a source of direct voltage having first and second terminals; a source of audio signals to be amplified; first and second transistors, each having input, output and common electrodes, said common and output electrodes of said first and second transistors being series connected between said first and second terminals of said source of voltage; utilization means coupled in parallel across said first transistor; biasing means coupled to the input electrode of said second transistor for enabling said second transistor to establish a substantially constant current flow therein, said biasing means including a direct current impedance series connected between said first terminal of said source of voltage and said first transistor; a third transistor having a main conduction path series coupled between the junction of said impedance and said first transistor and at least one resistor connected to a second terminal of said voltage source, said second transistor having a control electrode connected to said main conductor path of said third transistor, said third transistor having a control electrode coupled to a point of reference potentiaL for enabling said third transistor to alter the bias of said second transistor for maintaining said current substantially constant; and means for coupling said source of audio signals to said input electrode of said first transistor for causing voltage variations between said output and common electrodes of said first transistor corresponding to said audio signals, said first transistor voltage variations producing output signal variations in said utilization means.

Claim 7

An amplifier according to claim 4 wherein: temperature responsive means are coupled between said first terminal of said source of voltage and said point of reference potential.

Claim 8

An audio amplifier according to claim 5 wherein: said temperature responsive means comprises at least one semiconductor junction.