| 摘要 |
PROBLEM TO BE SOLVED: To provide a frequency measuring apparatus, for a pulse-shaped input signal, by which a stable and precise frequency can be found even when pulse widths are different and even when a noise or the like exists. SOLUTION: Measuring pulses c to a DFD (instantaneous frequency detection) circuit 14 and output latch pulses d to a data extraction circuit 8 are generated by a timing controller 15 on the basis of timing pulses b obtained in such a way that the pulse-shaped input signal a is detected by a signal detector 13. The measuring pulses c are sufficiently narrower (high frequency) than the pulse width of the input signal a, and frequency data is measured many times during one pulse period. For example, a frequency which is nearly in the central position of input signal pulses or whose generation frequency is highest is output from the data extraction circuit 18 as output data i.
|
