| 摘要 |
PURPOSE:To detect the fault of the data reception and the ground facilities through the phase detector by emitting the electric wave form the tuning circuit type transmission antenna of the mobile object such as the train or the like and via the contactless connection to the antenna of the ground side. CONSTITUTION:The output of fixed frequency f0 sent from oscillator 1 of the mobile object at the upper side A is amplified through amplifier 2, and then AC current i0 is flown to the transmission antenna consisting of loop coil L2 and capacitor C3 via transformer T1. In this case, both L2 and C3 feature -3dB with the phase synchronizing with frequency fl of -45 deg. from f0. When a connection is secured to C1 and L1 of the ground facilities at the lower side B while running of the mobile object, the value of virtual L2 changes to have resonance with f0. The parallel make and break is secured for C2 of the ground side to C1 via switch 4, and thus C2 and L3 feature resonance to frequency fh of +45 deg. at the make time. Then the phase difference between output (a) to (b) of the oscillator and T1 is detected through phase detector 3. Thus the detection becomes possible with a small amount of power consumption for the passage of the ground loop, the reception of the operation data given from ground side data input 6 via encoding circuit 5 and the fault of the ground facilities respectively. |
