Circuits
Amplifiers – Biasing (1)
- Amplifier devices may be biased so that when a sinusoid is applied the device
conducts (collector or drain current flows) for all or a portion of the cycle
- Where the amplifier does not conduct for a complete cycle the missing part
is restored by the flywheel effect in a parallel resonant (tank) circuit
- Audio and signal amplifers operate in Class A where the device is biased
to conduct for all of the cycle (360°); these are linear,
theoretical efficiency is 50% but 25-30% is more normal