Electronic power amplifier for delivering a constant power into a load impedance

Claim 2

An electronic power amplifier for delivering into a load impedance a constant power which does not depend on variations in the value of said impedance, the level of said power being controlled by the value of an input current, wherein said amplifier comprises at least two transistors T 1 and T 2 of complementary type, the base of the first transistor T 1 being connected to a line for the supply of current delivered by a control current source, the emitter of said transistor T 1 being connected on the one hand to one end of the load impedance and on the other hand connected directly to the base of the second transistor T 2 , the collector of said transistor T 1 being connected to a voltage supply of suitable polarity, the emitter of said transistor T 2 being connected to the current supply line and the collector of said transistor T 2 being connected to another end of the load impedance.

Claim 3

An electronic amplifier according to claim 1, wherein said amplifier comprises a push-pull arrangement of two amplifier units formed by the connections of transistors T 1 and T 2 in which the amplifiers accordingly operate in the Class B mode.

Claim 4

An electronic amplifier according to claim 1, wherein said amplifier further comprises a diode connected between the input of the emitter of the transistor T 2 and the current supply line from the current source.

Claim 5

An electronic power amplifier for delivering into a load impedance a constant power which does not depend on variations in the value of said impedance, the level of said power being controlled by the value of an input current, wherein said amplifier comprises at least a circuit of a predetermined conduction type, one amplifier circuit T 1 of the Darlington type and a transistor T 2 , said Darlington circuit T 1 and said transistor T.sub. 2 being of complementary conduction type, said transistor circuit T 1 comprising two transistors in series of the same type including a first transistor T a in which the base is connected by a line to a current supply source and the emitter is connected to the base of a second transistor T b , the collector of said transistor T a and of said transistor T b being connected to a current supply source, the emitter of said transistor T b being connected directly to the base of said transistor T 2 and the base said transistor T 2 being connected to the load impedance.

Claim 6

An electronic power amplifier for delivering into a load impedance a constant power which does not depend on variations in the value of said impedance, the level of said power being controlled by the value of an input current, wherein said amplifier comprises at least a circuit of a predetermined conduction type, one amplifier circuit T 1 of the Darlington type and a transistor T 2 , said Darlington circuit T 1 and said transistor T.sub. 2 being of complementary conduction type, said transistor circuit T 1 comprising two transistors in series of the same type including a first transistor T a in which the base is connected by a line to a current supply source and the emitter is connected to the base of a second transistor T b , the collector of said transistor T a and of said transistor T b being connected to a current supply source, the emitter of said transistor T b being connected directly to the base of said transistor T 2 and the base said transistor T 2 being connected to the load impedance.

Claim 7

An electronic amplifier according to claim 4, wherein said amplifier further comprises one other circuit of conduction type opposed to said predetermined conduction type, whereby said circuit of predetermined conduction type and said circuit of opposed conduction type operate in the class B mode.

Claim 8

An electronic amplifier according to claim 4, wherein said amplifier further comprises a diode connected between the input of the emitter of the transistor T 2 and the current supply line from the current source.