| 摘要 |
PURPOSE:To measure an input frequency f1 in a short time, by counting the input frequency f1 to a specific set value at a reference frequency f2 much less than the input frequency. CONSTITUTION:The input frequency f1 to be measured is converted into a pulse waveform, which is inputted to a gate circuit 2 together with a measurement start signal to output a start signal. Consequently, a counter 3 starts counting the pulse waveform of the input frequency f1 and the 2nd counter 4 starts counting the reference frequency f2. The 1st counter 3 once counting the pulse waveform up to the set value n1 outputs an end signal and the 2nd counter 4 also stops. The set value n1 and the counted value n2 of the counter 4 are inputted to an arithmetic circuit 7, whose arithmetic result is displayed on a display circuit 8. The arithmetic circuit 7 calculates the rate of the n1 and n2 and multiplies it by the reference frequency f2 to calculate the input frequency f2. Thus, the input frequency is measured in a short time. |
