This crowbar circuit for alternating current causes a quick fuse to blow when the load current exceeds a certain value. The circuit is from an American 80's documentation.
This circuit was obtained in a 1973s documentation. The transistors may be BC558 for the PNP and...
The sensors in this circuit that triggers when the temperature goes out of a certain range are...
Other operational amplifiers series, such as MC34072, MC34074, MC35071, MC35072, MC35074 d MC33071...