This Intersil circuit was found in a 1980s documentation. Operational are of the time, but current equivalents can be experienced. The graph with the circuit performance is given next to the diagram.
ON Semiconductor MC74VHX1Gx Logic ICs The Mouser Electronics series 74 Logic ICs are available for...
This circuit is from an 80's documentation. Equivalent transistors can be used. The circuit is...
This circuit was obtained from an English magazine from 1977. It is a toy musical instrument that...