This circuit triggers a relay when the set temperature is reached. The circuit is from an old documentation. The relay may be equivalent according to the transformer secondary voltage.
This circuit was found in American documentation from the 90's. The circuit applies to any...
We found this circuit in an English publication from 1980, but it can be assembled with BC548...
This circuit was found in the 1991 Electronics Experimenter's Handbook. It activates a relay when...