| 摘要 |
The invention concerns a communications system comprising a central communication unit (CCU) and at least one cable-less peripheral communication unit (PCU). These two units are linked via an electromagnetic coupling and carry out data exchange over a wave of predefined frequency and one-way energy transmission to supply the PCU with power. The purpose of the invention is to design a communications system with a CCU and at least one PCU and which is available at all times, in communications readiness and easy to operate. The solution lies in the following: the magnetic coupling is done with a band filter (15, 27) containing the coils (10, 12) and the data exchange from the PCU (11) to the CCU (1, 4) is done via the wave of predefined frequency by detuning or load alteration of the PCU-side L.C. oscillating circuit (27), while the amplitude changes caused by this in the CCU-side L.C. oscillating circuit (15) are demodulated, together with the modulated data signal transmitted by the CCU (1, 4), by the demodulation device (20) connected there; and the CCU (1, 4) is provided with a combinatorial circuit (19) in which the modulation data signal of the CCU (1, 4) is subtracted from the signal supplied by the demodulation device (20) so that a differential signal can be forwarded as the data signal of the PCU (11) for processing in the CCU (1, 4). |
