PURPOSE: To arbitrarily obtain the control characteristic of an opponent equipment by providing an electromagnet providing in its plunger a stem receiving force of the opponent equipment, position detector of the stem and an electric circuit supplying a driving current to a coil of the electromagnet.

CONSTITUTION: A throttle valve 2, controlling an intake amount, and a lever 3, receiving dashpot action in not more than a preset opening of the valve 2, are secured to a throttle valve shaft 1. A plunger 6, arranged in the center of a coil 5 of an electromagnet 4 performing the dashpot action, has a spring receiver 7 and a stopper 8. A brush 14 of a potentiometer, constituting a position detector 13, is mounted to a connecting rod 12. An electric circuit 18, which supplies to the coil 5 of the electromagnet 4 a driving current in accordance with a position of the stem 11, is provided. Electromagnetic force of the electromagnet 4 serves as the resistance of action by an opponent equipment. In this way, the opponent equipment enables its control characteristic to be arbitrarily obtained.