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.
The figure shows three circuits for using headphones in amplifiers with speakers that do not have...
In this charger, the charging current is basically limited by the LEDs. The transformer is a low...
This configuration is from an old integrated circuit manual. The circuit can be applied to modern...