High power audio amplifier system

Claim 2

A bridge audio amplifier comprising a current transformer having several secondary coils having identical current outputs of the same polarity, and a bridge comprising transistors with collectors-emitters interconnected in each arm of the bridge, the base of each transistor being connected to one end of one of said secondary coil windings, the emitters of each upper arm being connected to one end of an anti-parallel diode network, the other ends of two of the same coils being connected to the bases other ends of the anti-parallel diode networks, the collectors of said upper arm transistors connected to a source of D.C. power, the other end of the remaining coils being connected in common and said same common connection being connected to the junction of two series-connected diodes, a resistor connected in parallel to said series diodes, the remote anode from said junction being connected to the common emitter connection of the lower arms of said transistor bridge, and the remote cathode from said junction being connected to the return of said source of D.C. power.

Claim 3

The bridge audio amplifier as defined in claim 1 wherein each of the upper two arms Q1, Q2 of said class B bridge power transistor array comprises at least one transistor or a plurality of transistors connected in parallel, two diodes CR7a, b or CR6a, b connected anti-parallel to each other and a resistor R7 or R8, one terminal of said anti-parallel diodes connected to the common emitter circuit of said transistor arm, the other terminal of the said anti-parallel diodes connected to one terminal of said resistors R7 and R8, the other terminal of said resistor connected to the collector of said transistor arm, and the collectors of said upper two arm transistors Q1, Q2 connected to a source of D.C. power, and wherein each of the lower two arms Q3, Q4 of said Class B bridge power transistor array comprises at least one transistor or a plurality of transistors in parallel, the emitter circuits of said Lower two arms connected to one terminal of a resistor R5, the other terminal of said emitter circuit connected resistor connected to the return of said D.C. source of power, a pair of series connected diodes CR4, CR5 wherein the common terminal of said series connected diodes is connected to the junction of terminals of a pair of resistors R9, R10, the other terminal of one of the said pair of resistors connected to the collectors of one of the lower arm transistors R9 to Q3 collector, the other terminal of the other of said pair of resistors connected to the collectors of the other of the lower arm transistors, the input current end CR5 of said series connected diodes connected to the junction of said lower arm transistors emitter circuit and said emitter connected resistor R5 to Q3, Q4 emitter circuit, the output current end of said pair of series connected diodes CR4 connected to the return of said source of d.c. power and a diode CR3 whose current input terminal is connected to the emitter circuit of said lower arm transistors Q3, Q4 whose current output terminal is connected to the return of said source of D.C. power, and the emitter circuit of one of the said upper arm transistors Q1 connected to the collector circuit of one of the lower two arms of said lower arm transistors Q3, and the emitter circuit of the other of the said upper arm transistors Q2 connected to the collector circuit of another of the lower arm transistors Q4, and a pair of power output terminals, one terminal of said pair of power output terminals connected to one of the said upper and lower arm emitter-collector junctions Q1 emitters to Q3 collectors, the other terminal of said pair of power output terminals connected to the other of the said upper and lower arm emitter-collector junctions Q2 emitters to Q4 collectors, and a plurality of low resistance magnetically coupled two terminal sources of A.C. signal currents T2, one terminal of one of the said A.C. signal sources connected to the bases of an upper arm transistors, the other terminal connected to the junction of the associated resistor and anti-parallel diodes of the said upper transistor arm, one terminal of another of the said A.C. signal sources connected to the bases of the other upper arm transistors, the other terminal connected to the junction of the associated resistor and anti-parallel diodes of the said other upper transistor arm, one terminal of another of the said A.C. signal sources connected to the bases of a lower arm transistor, the other terminal of said A.C. signal source connected to the junction of the said series connected diodes, one terminal of another of the said A.C. signal sources connected to the bases of the other lower arm transistors, the other terminal of said A.C. signal source connected to the junction of said series connected diodes.

Claim 4

The bridge audio amplifier as defined in claim 2 wherein the said collector connected resistors on each of the two side arms of said bridge power transistor array comprise means to form a voltage divider, having the bases of each of said upper two arms of said bridge power transistor array connected to the mid-potential point of said voltage divider, wherein at no A.C. signal input current from the said low resistance magnetically coupled sources of A.C. signal currents, wherein the D.C. voltage between the emitter circuits of each of the said upper arm transistors to the return of said source of D.C. power follows the mid-potential point of said voltage dividers.

Claim 5

The bridge audio amplifier as defined in claim 3 wherein said fixed D.C. voltage between said upper arm transistors and the return of said source of D.C. power comprises means for producing stabilized quiescent D.C. collector to emitter voltage on all four arms of the said bridge power transistor array.

Claim 6

The bridge audio amplifier as defined in claim 2 wherein the junction point of said series connected diodes has a fixed D.C. voltage equal to the forward drop of the current output diodes of said pair of series connected diodes, wherein the said D.C. voltage at no A.C. signal input currents from the said low resistance magnetically coupled sources of A.C. signal currents is applied to the bases of the said lower arm transistors, wherein the D.C. voltage between the emitters of the said lower arm transistors and the return of said source of D.C. power follows the D.C. voltage across the said current output diode of said pair of series connected diodes, wherein the current through the said resistor connected between the emitter circuits of the lower arm transistors and the return of the said source of D.C. power is fixed proportional to the said emitter voltage and wherein the forward conduction potential across the said diode connected across the said resistor is greater than the voltage across the said resistor at no A.C. signal input current.

Claim 7

The bridge audio amplifier as defined in claim 5 wherein said fixed D.C. current through the said resistor connected to the emitter circuits of the said lower arms transistors and the return of the D.C. power source comprises means for producing stabilized quiescent D.C. current through all four arms of said transistor array.

Claim 8

The bridge audio amplifier as defined in claim 2 wherein the said plurality of magnetically coupled sources of A.C. signal currents produces all A.C. signal current means simultaneously, said A.C. signal currents that flow into the bases of the transistors of said upper two arms of said power transistor bridge phased 180* with respect to each other, said A.C. signal currents that flow into the bases of the transistors of the opposite arms of said power transistor bridge array phased at 0* with respect to each other, said A.C. signal currents that flow into the bases of the upper arms of said power transistor bridge array flow through the anti-parallel diodes coacting with each of the upper arms of said power transistor bridge array, and the said base drive currents of the said lower two arms flow through the said series connected diode pair coating with the lower two arms of said power transistor bridge array.

Claim 9

The bridge audio amplifier as defined in claim 7 wherein the said anti-parallel diodes coacting with the said upper transistor arms coact with the A.C. signal currents flowing through them to form direct paths for the A.C. signal currents to flow between the bases, and emitter circuits in each of the upper two arms of the said power transistor bridge comprises means for disabling the said D.C. collector to emitter voltage stabilization of the said power transistor bridge when A.C. signal input current exists independent of the frequency.

Claim 10

The bridge audio amplifier as defined in claim 7 wherein the said series connected diodes coacting with the said lower transistor arms coact with the A.C. signal currents flowing through them to form a direct path for the A.C. signal currents to flow between the bases and the emitter circuits of each of the lower two arms of said power transistor bridge comprises means for disabling the said D.C. current stabilization of the said power transistor bridge array when A.C. signal input currents exist independent of the frequency of these currents.

Claim 11

The bridge audio amplifier as defined in claim 2 wherein the said magnetically coupled sources of A.C. signal currents is a three-legged transformer with identical windings on the outer legs and no windings on the inner leg forming a magnetic shunt, said outer leg windings consisting of at least three coils, at least two of the said coils having equal turns, said equal coils being the secondary coils and the remaining coils of the said winding being the primary coils, and at least one primary coil of one of the said outer legs is connected in series with at least one identical primary coil of the outer leg coacting so that the magnetic flux produced in each Leg when A.C. signal currents flow in said series connected primary is summed in the said magnetic shunt to provide means for suppressing flux linkage between the said two outer leg windings thereby providing means for the induced A.C. flux level in one of the said outer legs to be independent of the flux level in the other.

Claim 12

The bridge audio amplifier as defined in claim 10 wherein the secondary coils of one of the said outer legs of the said transformer form the magnetically coupled A.C. base drive signal current means for one pair of adjacent upper and lower arms of said power transistor bridge array, and the secondary coils of the other said outer leg form the magnetically coupled base drive A.C. base drive signal means for the other pair of adjacent upper and lower arms of said power transistor bridge forming means for opposite arms of the said power transfer bridge to receive identical base drive A.C. signal currents independent of the voltage reflected back to the secondary coils by the said transistor bases.

Claim 13

The bridge audio amplifier as defined in claim 11 wherein the anti-parallel diodes of an upper arm of said power transistor array and the series connected diodes of the lower arm of the said power transistor array are forced into conduction simultaneously when A.C. signal currents exist, forming means for opposite arms of the said power transistor bridge to conduct current simultaneously when A.C. signal current exists and forming means for eliminating cross-over distortion.