Found in Electronics Now from the 1980s, this amplifier can also be seen in commercial amplifiers of the time. The integrated used is uncommon nowadays. The power is 33 W.
Using bipolar, FETs and unijunction this long-lasting timer can reach 10 hours with good quality...
This 1-transistor circuit for currents up to 50 mA was found in the August 1974 Radio Electronics...
We found this circuit in a 1969 General Electric documentation. The circuit uses transistors of the...