Switching amplifier system

Claim 2

An audio amplifier system comprising: a source of audio input signal; means to pulse width modulate at least one high frequency pulse train with the audio input signal means for providing a power gain to the modulated pulse train and passing the modulated pulse train through a high frequency transformer; means for demodulating the modulated pulse train whereby the increased magnitude of the audio input signal is recovered and for filtering the recovered signals to remove non-audio signals; polarity detector means for providing audio signal to a load in accordance with the polarity of the input signal.

Claim 3

An audio amplifier system comprising: a source of audio input signal; a full wave rectifier for converting the AC input signal into a positive output equal to the magnitude of the input; a pulse width modulator for converting the applied input signal from said rectifier into two pulse train outputs of constant repetition rate and amplitude and equal duty cycles; an electronic switch for each pulse train adapted to open and close in response to the presence or absence of a pulse; a transformer having a secondary centertapped whereby the ends are of opposite polarity by a substantially equal amount; a first full wave rectifier for converting the positive AC voltage from said transformer into a pulsating positive direct current signal; a second full wave rectifier for converting the negative AC voltage into a pulsating negative direct current signal; first and second averaging filters for blocking the flow of frequencies above the audio frequency band whereby the audio signal is reconstructed; an electronic switch for alternately connecting a load to said first and second averaging filters; and a polarity detector for controlling said electronic switch.

Claim 4

An audio amplifier system comprising: a source of audio input signal; a full wave rectifier for converting the AC input signal into a positive output equal to the magnitude of the input; a pulse width modulator for converting the applied input signal from said rectifier into two pulse train outputs of constant repetition rate and amplitude and equal duty cycles; an electronic switch for each pulse train adapted to open and close in response to the presence or absence of a pulse; a transformer having a secondary centertapped whereby the ends are of opposite polarity by a substantially equal amount; a first full wave rectifier for converting the positive AC voltage from said transformer into a pulsating positive direct current signal; a second full wave rectifier for converting the negative AC voltage into a pulsating negative direct current signal; first and second averaging filters for blocking the flow of frequencies above the audio frequency band whereby the audio signal is reconstructed; an electronic switch for alternately connecting a load to said first and second averaging filters; and a polarity detector for controlling said electronic switch.