Abstract: The present invention relates to a feedforward-error-correction amplifier system comprising a switching circuit, a linear-amplification means, and a summing network, wherein an amplifier-system input signal is connected to a first input port of the linear-amplification means, and an output voltage signal produced at an output port of the linear-amplification means is fed to a first input port of the summing network, a signal which is a function of a current flowing in the output port of the linear-amplification means is fed to an input port of said switching circuit, said switching circuit having an output port at which a switching output signal is produced and which switching output signal is fed to another input port of the summing network, an output current flowing in the output port of the switching circuit having a time rate of change limited by a low-pass-filter means, a sensing signal which is a function of the switching output signal being fed to another input port of the linear-amplification means, t

Abstract: A high-efficiency low-distortion parallel amplifier or regulator is driven by an input signal source V.sub.i. An input signal passes to a linear circuit LC, and the output current i.sub.1 from the linear circuit passes to the input of a switching circuit SC. Alternatively, the input to the switching circuit may be any other signal that is a function of the linear-circuit output current. The output of the switching circuit passes through a coupling network CN and is applied with the output current of the linear circuit to a load impedance ZL. The output of the switching circuit acts to reduce the output current of the linear circuit so that the power it supplies is low. A low linear-circuit output current is usually sufficient to drive the switching circuit and coupling network to the maximum current required by the load. The system automatically adjusts independently of the load impedence so that with high output current most of the current is supplied by the switching circuit.

Abstract: An amplifier system comprising at least two tracking switching regulators or a dual-output regulator, which regulators vary the voltage across the output stage at the signal or its envelope rate.