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.
We found this circuit in a Radio Experimenter Handbook from the 90s. The circuit uses 741 op amps...
This circuit was suggested by an Electronic Design from the 90s. Its purpose is to detect...
This circuit (2009) has driver control through the RTS signal or in automatic mode through the...