This is the factory setting (National Semiconductor) of the TDA2006 as an audio amplifier. The circuit works with 24 V and the diodes can be 1N4148.
Used with telephones at the time, this circuit was found in Popular Electronics from the 90s. The...
Found in a 1965 CQ magazine, this circuit uses period components. The unijunction transistor can...
This dimmer configuration is quite old, as it was found in a 1967 publication. The triac can be of...