ABSTRACT
This chapter describes pushpull crossover displacement implemented by controlling the displacer from the amplifier voltage output. A Class-A amplifier can be 50" efficient with a maximum sinewave output and have the potential to give the best linearity. A Blameless amplifier design gives very good linearity-typically below 0.001", at 1 kHz-especially in its Load-Invariant. In a conventional optimal Class-B amplifier, the crossover events are evenly spaced in time. In the crossover-displacement amplifier, the crossover events are asymmetrical in time and put energy into both even and odd harmonics when operating above the transition. The most straightforward way to implement crossover displacement is to simply connect a suitable power resistor between the output rail and a supply rail. A constant-current source is connected between the output and negative rail. Efficiency is better as no output power is dissipated due to the high dynamic impedance of the current source.
