PURPOSE: To secure the extraction of the higher harmonic wave in the desired order at a high relative level through a simple constitution and with the small-scale filter and amplifier, by arranging the higher-ordered pulses extracted in the divided basic peroid with almost equal distance between.

CONSTITUTION: The inpout signals sent input terminal 26 are combined with FF16∼22, NOR gate 23 and 24 plus OR gate 25, and then transmitted through output terminal 27. Here, FF16∼18 plus NOR gate 24 form a divider of 1/5 pulse ratio 1:4, and the signals are led to the binary counters of FF19∼22. Thus, the desired order-numbered higher harmonic wave can be extracted at a higher relative level through a simple constitution and with the small-scale filter ad amplifier, by arranging the higher-ordered pulses extracted in the divided basic peroid almost equidistantly.