| 摘要 |
PURPOSE:To set the delay time with high accuracy by using an oscillator and a counter which performs a counting operation with the output of the oscillator. CONSTITUTION:When the input signal I which is always held at a high level disappears, a delay circuit 1 works to deliver a delay output (a) having a delay time tau1 which is a little longer than a period covering from disapearance of the signal I to the rise time point of a counter 5. The output (a) is supplied to an AND memory circuit 6 as well as to an OR circuit 7 as one of its inputs. At the same time, a differential output (b) is generated from a differentiating circuit 2 when the signal I disappears. The output (b) is applied to a gate circuit 3 as the 1st switch signal. The circuit 3 either one of oscillation outputs f1 and f2 of high and low frequencies sent from oscillating circuits 4A and 4B and supplies it to the counter 5. The counter 5 is equal to a binary counter and kept reset while the signal I is kept at a high level. Then the counter 5 can perform counting operations with disappearance of the signal I. |
