HEATING DEVICE

Disclosed is a heating device comprising a heating resistor assembly comprising a positive terminal (13), a negative terminal (14), and heating resistors (10, 10a, 10b) connected in series between the positive terminal (13) and the negative terminal (14), and a transistor switch (21) connected in series with the heating resistors (10). According the invention a first half (10a) of the heating resistors connects the positive terminal (13) to the transistor switch (21) and a second half (10b) of the heating resistors (10) connects the transistor switch (21) to the negative terminal (14).