We found this circuit in the October 1987 Radio Electronics magazine. The triac must be controlled according to the heater. The transformer has a low current, of the order of a few hundred mA.
We found this function generator with two FET operators in a 1996 Texas Instruments application manual....
This circuit was obtained from an English magazine from 1979, but can be easily assembled today...
The integrated circuit used in this 2002 project is not very common. It is powered directly by the...