This circuit is from a National Semiconductor manual from the 1980s. The integrated circuit is rare today and next to the diagram we have the formula for calculating the components.
This well-known siren configuration using complementary transistors is from a 1980s documentation. The...
This circuit was found in an old American magazine and could make use of more modern components...
This circuit is from the Philips integrated circuits manual of 1990. It is intended for magnetic...