| 摘要 |
PURPOSE:To simplify the constitution and to miniaturize the device by controlling a latching relay by means of a control data to change a resistance value for controlling load thereby eliminating the need for a stepping motor. CONSTITUTION:A transmission signal Vs transmitted from a central controller 1 is received by each terminal device 2 via a signal line 3, the transmission signal Vs is rectified and smoothed by a power supply circuit 10 to form a power supply Vcc for terminal circuit and also a prescribed signal processing is conducted at a terminal 11. That is, the terminal circuit 11 discriminates whether or not an address data DA transsmitted in the trasmission signal Vs is coincident with the own specific address and when the coincidence of the address is obtained, output signals Vc1-Vc4 corresponding to each bit of the control data Dc transmitted in the transmission signal Vs and an output signal Vc5 setting a relay drive timing are outputted. The output signals Vc1-Vc5 turn on/off the latching relays Ry1- Ry4 so as to adjust the resistance value among O1-O2 and O2-O3 controlling the load. |
