We found this circuit in a magazine 73 for radio amateurs from the 80's. The circuit makes use of an epochal component which is programmed according to the table beside the diagram.
This circuit functions as a thermostat triggering a relay when the boil control temperature...
The figure shows how to connect a relay to obtain the latch effect. The circuit is from an...
With this circuit it is possible to use a DC buzzer (not a transducer) as an extension of the...