| 摘要 |
PURPOSE:To realize a long-time operation with high accuracy for a timer circuit, by using the clock pulse in a digital way. CONSTITUTION:The one output of the oscillator 11 is connected to the up-count input UP of the up-down counter 13 via the AND gate 12 that uses the input pulse (e) as a different input, and the other output is connected to the down- count DOWN of the counter 13 from the N-division counter 14 via the AND gate 15. The AND gate 12 opens while the pulse (e) of a prescribed time width Te is received, and thus the counter 13 counts the clocks of the oscillator 11 to the up- side. When a timer action is started, the gate 15 opens to send the N-divided clock of the clock output of the oscillator 11 to the counter 13 to give a down-count to the clock. When the count value becomes zero, the gate 15 closes to stop the operation of the counter 13. |
