PURPOSE: To simplify the titled transmitter by supporting turnably a rotor on a stator and providing a pairied transmission coil and reception coil respectively to the stator and rotor to transmit the signal contactlessly.

CONSTITUTION: A stator head 1 is constituted of nonmagnetic substance on the stator 7, a transmission coil 3 and a reception coil 4 are wound around a ferrite rod 8 and connected to a control section (not shown). Moreover, a rotary head 2 of nonmagnetic substance is provided turnably around the stator head 1, the reception coil 5 and the transmission coil 6 are imbedded in parallel with the coils 3, 4 to transmit/receive data contactlessly between the reception coil 5 and the transmission coil 3 and between the transmission coil 6 and the reception coil 4 electrically. Thus, data is transmitted and received in time division by using a lot of kinds of signals to attain ease of maintenance. This system is suitable for the drive control of a crane.