This is one of the channels of an amplifier suggested by Westinghouse in 1970s documentation. The circuit uses components from the era and no information about the transformer is given.
With the figure circuit it is possible to control the amount of heat generated by the heating...
This Texas Instruments circuit is from the 80's. However, it can be implemented with modern...
In the figure we have a circuit that allows us to obtain a variable voltage of approximately 0.5 to 25 V...