Title:
FREQUENCY MEASURING APPARATUS
Document Type and Number:
Japanese Patent JP3126219
Kind Code:
B2
Abstract:
PURPOSE: To measure the frequency of a signal to be measured by counting the pulses of a first reference frequency with a first counter during a period to be measured, which is obtained by dividing the frequency of the signal to be measured with a specified frequency dividing ratio, counting the reference periods with a second reference frequency, which is proportional to the frequency dividing ratio, outputting pulses at every counting of the first counted value, and counting the pulses.
CONSTITUTION: A period control part 8 receives a signal to be measured having a frequency F through an input terminal and divides the frequency with a frequency dividing ratio M. A first counter 9 receives a period Ta obtained with the control part 8 and a first reference frequency signal Fa, obtains the counted value N=Ta×Fa and holds the value in a latch 10. A program frequency divider 11 counts the pulses of a second reference frequency signal Fb for a reference period Tb and outputs the pulses at every N counts during the period. A second counter 12 counts the pulses outputted from the frequency divider 11 and obtains the counted value C. The counted value C indicates the frequency F of the signal to be measured. The obtained frequency is displayed on a digital display device 13.
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Inventors:
Shinichi Akita
Application Number:
JP15414492A
Publication Date:
January 22, 2001
Filing Date:
May 22, 1992
Export Citation:
Assignee:
New Japan Radio Co., Ltd.
International Classes:
G01R23/10; (IPC1-7): G01R23/10
Domestic Patent References:
| JP63135870A | ||||
| JP5894234A | ||||
| JP5847270A | ||||
| JP55117973A |
Attorney, Agent or Firm:
Tsuneaki Nagao