This high impedance amplifier is from 1985 documentation by General Electronic. The amplifier with FET at the entrance is from the period and the source is 9 V.
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...