Found in an American publication of 1968, this circuit makes use of a pilot light of the time. It can be replaced with LED with appropriate series resistor. Transistors may be modern equivalents.
The circuit shown is from the Motorola Linear Databook from 1990. The circuit has two outputs with...
Suggested by General Electric in 1965 documentation, this circuit controls the current at a load...
This filter for the scratching noise common in record players was found in Radio Electronics from the...