This simple circuit can make use of any general-purpose transistor. The power comes from the circuit being analyzed.
This circuit was found in an Electronic Design. It makes use of a relaxation oscillator to trigger...
This circuit is from a 1967 publication. The potentiometer above 4M7 is the critical component. The...
This small 2-transistor amplifier was found in the Radio Electronics magazine of May 1959. The...