This circuit was found in an old GE manual. It uses a thermocouple as a sensor. The SCR must be in accordance with the power of the controlled load.
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...