| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide the electronic equipment system which prevents a unit from being destroyed even when the unit is mounted on a back board in a wrong power source connection state. SOLUTION: The back board 1 has a power source terminal 10 connected to, for example, a power source A of -45V and a ground terminal 12 connected to a ground G respectively and supplies a specific DC voltage to a mounted unit 2. A diode 22 which performs rectifying operation is connected to the plus side of a power source part 20 as a DC-DC converter and a terminal 26. The diode 22 has its cathode side connected to the plus side of a power source part 20 and its anode side connected to a terminal 22. Even when the power supply wires of the back board 1 are reversely connected, namely, when the power source A is connected to the ground terminal 12 and the ground G is connected to the power source terminal 10, no current flows to the power source part 20, which is therefore never broken.</p> |
