Switch mode - class B power amplifier

An amplifier configuration, which operates at the theoretical efficiency of a class B amplifier, for amplification of an input signal to be applied to a load, comprising:

• a power source for providing a power supply voltage of V between one output terminal and a ground potential;
• a first circuit responsive to said input signal for deriving a square wave switching signal synchronous with said input signal;
• a second circuit responsive to said square wave switching signal to provide a square wave power control signal having alternate amplitude states of the voltage V and ground at an output terminal that is connected to one side of the load;
• and
• a third circuit having first and second input terminals receiving the input signal and the control signal, respectively, and having an output terminal connected to the other side of the load;
• said third circuit being responsive to said power control signal to alternately provide said V voltage and ground at the output terminal thereof when the input signal is blocked from said first input terminal, the output of said third circuit then being in phase with that of said second circuit whereby no signal is developed therebetween;
• said third circuit being responsive to the application of said input and control signals thereto so as to provide amplification of said input signal such that the zero to peak value of the input signal will drive the output thereof between one of V and ground and the inverse thereof for alternate states of said switching signal;
• whereby a load driving voltage is obtained between the output terminals of said second and third circuits that has a peak-to-peak amplitude of twice the supply voltage V.