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.
This shield circuit uses a common CMOS port. The voltage depends on the interfaced logic. The...
This circuit was published in Popular Electronics from the 90's. The components are common, as...
This circuit with SCR was found in an old documentation. The SCR can be the TIC106, and the...