Transistor amplifier circuit with comparator - uses difference between reference and output to control current sink in bias circuit (NL 29.8.77)

摘要

The transistor amplifier has a comparator (4) to generate an error signal representing the difference between a reference voltage and the amplifier output voltage. The error signal controls amplifier (1) bias circuit. The bias circuit contains a variable current sink (5) to remove bia current under the control of the error signal. The bias circuit comprises a Zener diode connected to bias resistors coupled to the base of the amplifier. The output is taken across the amplifier collector resistor.