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 from a 1980 publication, converts the temperature sensed by Q1 into a frequency in a...
This oscillator has its frequency controlled by crystal and its frequency can be between 100 kHz...
The author has many books he had written in Eglish (See the Biography) published by famous...