Bridge amplifier suitable for manufacture in monolithic integrated circuit form

Claim 2

A bridge amplifier circuit for developing an output signal across an electrical load having first and second terminals, which output signal has a magnitude that varies in linear manner in response to the varying magnitude of an input signal having portions of first and second polarities, the bridge amplifier circuit including in combination: first switch means having a first terminal adapted to receive a direct current potential, a control terminal adapted to receive the input signal, and a second terminal connected to the first terminal of the electrical load, said first switch means being rendered conductive in response to the portions of the input signal of the first polarity to apply said direct current potential to the first terminal of the electrical load; first amplifier means having a first electrode connected to the second terminal of the electrical load and a control electrode adapted to receive the input signal, said first amplifier means being responsive to the variable magnitude of the portions of the input signal of the first polarity to vary the magnitude of a first current flowing through the electrical load in a first direction in a linear manner with the variable magnitude of the portions of the input signal of the first polarity; second switch means having a first terminal adapted to receive said direct current potential, a control terminal adapted to receive the input signal and a second terminal connected to the second terminal of the electrical load, said second switch means being rendered conductive in response to the portions of the input signal of the second polarity to thereby apply said direct current potential to the second terminal of the electrical load; and second amplifier means having a first electrode connected to the first terminal of the electrical load and a control electrode adapted to receive the input signal, said second amplifier means being responsive to the variable magnitude of the portions of the input signal of the second polarity to vary the Magnitude of a second current flowing through the electrical load in a second direction in a linear manner with the variable magnitude of the portions of the input signal of the second polarity.

Claim 3

The bridge amplifier circuit of claim 1 wherein one of said first and said second switch means includes a silicon controlled rectifier means having an anode, a cathode and a gate.

Claim 4

The bridge amplifier circuit of claim 2 wherein said one of said first and said second switch means further includes: driver means including a control terminal connected to receive said input signal, a first terminal connected to receive a direct current potential and a second terminal; inverter means having a control terminal connected to said second terminal of said driver means, a first terminal connected to one of said anode and cathode of said silicon controlled rectifier means, and a second terminal connected to said gate of said silicon controlled rectifier means; and switchable electron control means having a first terminal connected to receive a direct current potential, a control terminal connected to the other said anode and cathode of said silicon controlled rectifier means, and a second terminal connected to the electrical load.

Claim 5

The bridge amplifier circuit of claim 3 wherein said driver means, said inverter means and said switchable electron control means respectively include a first transistor, a second transistor and a third transistor.

Claim 6

The bridge amplifier circuit of claim 1 wherein said first amplifier means includes a transistor having a collector forming said first electrode, a base forming said control electrode.

Claim 7

The bridge amplifier circuit of claim 1 wherein said second amplifier means includes a transistor having a collector forming said first electrode, a base forming said control electrode.

Claim 8

The bridge amplifier circuit of claim 1 wherein: said first switch means and said first amplifier means include driving amplifier means; and said second switch means and said second amplifier means include driving inverter means.

Claim 9

The bridge amplifier circuit of claim 7 wherein said driving amplifier means and said driving inverter means are both provided by a differential amplifier means.

Claim 10

A monolithic bridge amplifier for developing an output signal which has a magnitude that varies in a linear manner with a variable magnitude of an input signal, the output signal having an increased power level with respect to the input signal and the output signal being developed across an electrical load with first and second terminals in response to first and second differential input signals each having portions of first and second polarities, the monolithic bridge amplifier including in combination: first conductive means for providing a first direct current potential of a first polarity; second conductive means for providing a second direct current potential of a second polarity; first switch means having a first terminal connected to said first conductive means, a control terminal adapted to receive the first differential input signal, and a second terminal connected to the first terminal of the electrical load, said first switch means being rendered conductive in response to the portions of the first differential signal of the first polarity to thereby apply said first direct current potential to the first terminal of the electrical load; first amplifier means having a first electrode connected to the second terminal of the electrical load, a control electrode adapted to receive the first differential input signal, and a second electrode connected to said second conductive means, said first amplifier means being responsive to the time variable magnitude of said portions of the first differential input signal of the first polarity to control the magnitude of a first current flowing through said first switch means and the electrical load in a first direction so that said magnitude varies in a linear manner with the variable magnitude of the portions of the first differential input signal of the first polarity; second switch means having a first terminal connected to said first conductive means, a control terminal adapted to receive the second differential input signal, and a second terminal connected to the second terminal of the electrical load, said second switch means being rendered conductive in response to the portions of the second differential signal of the first polarity to apply said first direct current potential to the second terminal of the electrical load; and second amplifier means having a first electrode connected to the first terminal of the electrical load, a control electrode adapted to receive the second differential input signal, and a second electrode connected to said second conductive means, said second amplifier means being responsive to the variable magnitude of said portions of the second differential input signal of the first polarity to control the magnitude of a second current flowing through said second switch means and the electrical load in a second direction so that said magnitude of said second current varies in a linear manner with the variable magnitude of the portions of the second differential signal of the second polarity.

Claim 11

A monolithic bridge amplifier for developing an output signal which has a magnitude that varies in a linear manner with a variable magnitude of an input signal, the output signal having an increased power level with respect to the input signal and the output signal being developed across an electrical load with first and second terminals in response to first and second differential input signals each having portions of first and second polarities, the monolithic bridge amplifier including in combination: first conductive means for providing a first direct current potential of a first polarity; second conductive means for providing a second direct current potential of a second polarity; first switch means having a first terminal connected to said first conductive means, a control terminal adapted to receive the first differential input signal, and a second terminal connected to the first terminal of the electrical load, said first switch means being rendered conductive in response to the portions of the first differential signal of the first polarity to thereby apply said first direct current potential to the first terminal of the electrical load; first amplifier means having a first electrode connected to the second terminal of the electrical load, a control electrode adapted to receive the first differential input signal, and a second electrode connected to said second conductive means, said first amplifier means being responsive to the time variable magnitude of said portions of the first differential input signal of the first polarity to control the magnitude of a first current flowing through said first switch means and the electrical load in a first direction so that said magnitude varies in a linear manner with the variable magnitude of the portions of the first differential input signal of the first polarity; second switch means having a first terminal connected to said first conductive means, a control terminal adapted to receive the second differential input signal, and a second terminal connected to the second terminal of the electrical load, said second switch means being rendered conductive in response to the portions of the second differential signal of the first polarity to apply said first direct current potential to the second terminal of the electrical load; and second amplifier means having a first electrode connected to the first terminal of the electrical load, a control electrode adapted to receive the second differential input signal, and a second electrode connected to said second conductive means, said second amplifier means being responsive to the variable magnitude of said portions of the second differential input signal of the first polarity to control the magnitude of a second current flowing through said second switch means and the electrical load in a second direction so that said magnitude of said second current varies in a linear manner with the variable magnitude of the portions of the second differential signal of the second polarity.

Claim 12

The monolithic bridge amplifier of claim 9 wherein said first switch means and said second switch means each include: first transistor means having a first electrode connected to one of said conductive means and second and control electrodes, second transistor means having a control electrode connected to said second electrode of said first transistor means and a second electrode connected to said control electrode of said first transistor means and a first electrode, first resistive means connecting said second electrode of said second transistor means and said control electrode of said first transistor means to said one of said conductive means; first circuit means connecting said first electrode of said second transistor means to the other of said conductive means; second circuit means connecting said control terminal of said switch means to said control electrode of said first transistor means; and third circuit means connecting said first electrode of said second transistor means to the electrical load.

Claim 13

The monolithic bridge amplifier of claim 10 wherein said second circuit means includes a driver amplifier having its input terminal connected to said input terminal of said switch means and an output terminal connected to said control electrode of said first transistor means.

Claim 14

The monolithic bridge amplifier of claim 10 wherein said third circuit means includes a plurality of Darlington connected transistors.

Claim 15

The monolithic bridge amplifier of claim 9 wherein said first amplifier means and said second amplifier means each include: Darlington transistor means having equivalent emitter, base and collector electrodes; and diode means connected between said equivalent base electrodes and one of said conductive means for providing quiescent bias potentials.

Claim 16

The monolithic bridge amplifier circuit of claim 13 wherein said diode means also provide quiescent bias voltages to said first switch means and to said second switch means.