| 摘要 |
PURPOSE:To increase the lifetime of a DC power supply by setting a timer function into a printer using a DC power supply and turning off automatically power supply switch. CONSTITUTION:When a push-switch 1 for power supply ON is pushed, a direct current flows within a printer and a relay control part 3 turns on a relay 1 as shown by a dotted line. Hereafter the direct current is supplied to the printer through the relay 1. Thus an oscillator 4 produces pulses and an IC counter 5 counts these pulses. A counter control part 6 stops the counting action of the counter 5 while the printer is executing a print instruction and then sets the count value of the counter 5 to zero after a print instruction is through and when a power supply is applied. The count value of the printer 5 reaches a set level as long as the printer has no working for a fixed period of time. Thus a signal is sent to a relay control part 7 and the part 7 turns off a relay 8 as shown by a dotted line. As a result, both relays 2 and 8 are reset to the states shown by the solid lines respectively since the direct current flowing within the printer.
|
