This temperature control was found in General Electric documentation from the 90's. The circuit uses a 10k ohm NTC sensor as a sensor. The triac must be in accordance with the controlled load.
This circuit is from a Radio Electronics from April 1964. Note the unijunction transistor of the...
This circuit was found in a 1970s documentation. The integrated circuit used is uncommon today....
Found in the October 1972 issue of Radio Electronics magazine, this circuit generates modulated pulses....