| 摘要 |
PURPOSE:To reduce the number of terminals exclusively used for supplying electric power so that the terminals can be prevented from being damaged when a board is wrongly connected by constituting each board to have control terminals and control signal sources to each receiving power supply, a mother board to have control lines, and a power supply board to have an actuation circuit which actuates power supply upon receiving a control signal. CONSTITUTION:Different kinds of electric power having different voltages are respectively supplied to boards 3-5 from a power supply board 2 through the power supply line 10 of a mother board 1. The power supply input of each board commonly uses the terminal 5 of an input-output port 7. Control lines 8 are used for transmitting the loop signal of a control line loop 9, namely a control signal to the board 2. The board 2 is a multi-output power source and, when a control signal arrives at one of the control lines 8 as a result of the insertion of one board, the corresponding power source circuit is actuated. Since the input-output port terminals of the control line loop 9 of each board has a different number, the damage of the terminals can be prevented even when any one of the boards is wrongly inserted. |
