Signal transmission system

PURPOSE:To transmit a control signal easily and securely without any contact by transmitting and receiving a signal magnetic field between one conductor provided to a signal transmission line and a magnetism receiving coil provided surrounding the conductor in a control signal transmission system. CONSTITUTION:A signal transmission line 2 which transmits a control signal is provided with a magnetism receiving coil 4 provided to a control signal reception part 3 so that the transmission line 2 penetrates the coil, and on the basis of the control signal transmitted to the signal transmission line 2, a signal magnetic field 8 is produced around the signal transmission line 2 and detected by the magnetism receiving coil 4 to receive the control signal transmitted to the signal transmissin line 2. Therefore, even when the control operation of a device 7 to be controlled by the control signal moves together with the control-signal reception part 3, signal transmission is achieved without any contact, thus exercising the secure control free from malfunction due to noise.