| 摘要 |
PURPOSE:To realize an inexpensive and sure circuit aby using a changeover switch of nonshorting type and utilizing that the circuit is opened without fail when the said switch is changed over to omit the reset time constant decision. CONSTITUTION:When a power switch depressed to turn ''ON'' the power switch, a contact piece 8 of a reset switch 4 is moved in the direction of arrow A, a contact 9 is detached from other contacts 10, 11 to turn on a transistor (TR) 5, the level of a reset terminal 7 of a microprocessor 6 goes to a low level and the circuit is reset in this state. When the contact piece 8 moves further and the contacts 9, 11 are contacted, the TR5 is turned off and the reset is finished. The reset is ensured by prolonging sufficiently the time where both the contacts 10, 11 are not contacted longer than the time required for reset, allowing to eliminate the need for the adjustment for the time constant. |
