TWO-WIRE POWER TRANSMITTING/RECEIVING DEVICE AND ITS METHOD

摘要

When electric power is fed from a transmitting device (1), an FET (103) is turned on, and the DC current of +12 V of a power source (101) is fed to receiving devices. When transmission data is transmitted from the transmitting device (1), a DC current of +5 V of a power source (102-1) is fed to a terminal (a), and a transistor (104) is turned on/off by a pulse-like voltage change of the transmission data. The transmission data are outputted as a signal of a pulse-like output waveform of 0 V ⇔ +5 V to each receiving device. When the transmitting device (1) receives the reply data from a receiving device, the receiving device changes the voltage of +3.5 V ⇔ +5 V like a pulse as reply data. This voltage change is detected by a photo-coupler (105), and the transmitting device (1) receives the reply data from the receiving device.