PURPOSE: To provide possibility of operation control of other electromagnetic components while the operating conditions of a specific electromagnetic component is maintained by modulation of the pulse width by installing inside of the device a pulse generation part and a pulse width modulation part, and impressing a pulse voltage with the pulse width modulated on electromagnetic component.

CONSTITUTION: A model car 4 of a railroad model set 1 is placed on a pair of feeder rails 3a, 3b arranged parallel on the oversurface of a road bed 2. The main switch 13 of a control box 5 is turned on, and a pulse voltage is impressed between the feeder rails 3a, 3b through a lead 6. If the duty ratio of the pulse voltage is small at this time, a cabin lamp 7 and headlight as non-electromagnetic components of the model car 4 are lighted up, while a motor M as electromagnetic component remains out of operation. If a rotary knob 14 on the control box 5 is turned to change the resistance value of a variable resistor and increase the duty ratio, the cabin lamp 7 and headlight are continued lighting up and also the motor M is put in operation.