This trigger circuit was found in an American documentation from the 1980s. The amplifiers used can be replaced by equivalents with characteristics according to the frequency.
This wired intercom circuit was found in an English publication from the 80's. The integrated...
This triac temperature control circuit was found in an 80s power semiconductor documentation. The circuit...
This circuit is from 1998 documentation. The coils consist of the number of turns indicated on...