A heating system including a power supply and a heating element for conducting
a current from the power supply. A temperature sensing device is adopted to detect
a temperature of the heating element, and a switch is connected in a circuit containing
the power supply and the heating element to switch the current on or off. Further,
a microprocessor produces a pulse-width-modulated signal as a function of the detected
temperature, where the pulse-width-modulated signal drives the switch.