The development and testing of the bi-polar synchronous rectifier (BPSR)

This paper discusses the operation of the bi-polar synchronous rectifier (BPSR) a special purpose low frequency amplifier topology. Energy conversion through an output transformer is done at a frequency much higher than the desired operating waveform frequency. An active rectifier demodulates the switched waveform passing only the desired low frequency waveform to the load. This feature can lead to substantial size and weight reduction in the amplifier as transformer magnetic volume decreases with increasing frequency. The technology allows full low frequency Class-D amplifiers to be realized with comparable efficiencies, but with much higher power densities.