| 摘要 |
PURPOSE:To prevent a trouble that is due to misresetting of a switch, by detecting a key switch signal on a CPU console panel and breaking a switch circuit to switch the voltage of a high or low margin test. CONSTITUTION:The output voltage is set at a high level at a position U of the 1st switch 15 for a high margin test; while the output voltage is set at a low level at a position L for a low margin test respectively. Now the key switch on a console panel is locked to actuate a CPU20 with the switch 15 kept at the position U. Therefore a driving circuit 22 has no actuation. As a result, a relay 21 is not driven and a relay switch 23 is opened. Then relays 17 and 19 are not driven. Therefore a synthetic resistance of resistances 8, 11, 9 and 12 is inserted between the error detecting input of an error amplifier 2 and a ground. The stabilized output voltage 5V thus obtained is applied to each part of the CPU20 to have a normal operation. |
