| 摘要 |
PURPOSE:To simplify the constitution by changing a switch or a short-pin within a prescribed time after the application of a power supply to change over the condition into the test condition. CONSTITUTION:The state of the switch 5 is read by a control circuit 4 comprising a microcomputer and the operating state is decided. Since the switch 5 is changed over normally while power is not applied, there is no problem even if the test condition is obtained by changing over the switch 5 while power is applied. When the state 1 of a DC power supply is a steady-state from 0V, the switch state 2 is read once after a time T1, and the switch state 2 is read further after a time T2. The program has only to be formed so as to obtain the test state only when the switching state is changed from the before state. Thus, the normal state and the test state are changed over by changing over the switch within a prescribed time, allowing to eliminate the need for a switch for changing over the test state. |
