Title:
METHOD AND DEIVCE FOR ERASING NOISE PRESENTED IN AC ELECTRICSIGNAL
Document Type and Number:
Japanese Patent JPS60125014
Kind Code:
A
Abstract:
A noise blanking circuit for eliminating evidence of noise present :n an incoming alternating electrical control signal, such as a shaft encoder or tachometer signal in a servo control circuit, is disclosed. The alternating electrical signal is input to a first input (A) of a shift register (44) having a plurality of outputs (C, E, G, J). Clock signals having a preselected frequency are input to a second input (B) of the shift register (44) for digitally sampling the alternating electrical signal at the times of occurrence of the clock signals so as to produce digital samples shiftably stored in respective storage locations of the shift register (44), which are connected to the plurality of outputs (C, E, G, J) of the shift register. The digital samples appearing at predetermined ones of the plurality of outputs (C, E, G, J) of the shift register (44) are input to a logic circuit (50...60) for producing a first logic state (low state) as an output signal, when a first logic state appears at the predetermined ones of the plurality of outputs (C, E, G, J) of the shift register (44), and a second logic state (high state) as the output signal, when a second logic state appears at the predetermined ones of the plurality of outputs (C, E, G, J) of the shift register (44). The selectivity of the noise blanking circuit can be selected by adjusting the clock signal frequency and/or the number of storage locations included in the shift register (44) and/or changing the predetermined ones of the plurality of outputs (C, E, G, J) of the shift register (44) which are input to the logic circuit (50...60).
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Inventors:
FURANKU DABURIYU RIN
Application Number:
JP16029884A
Publication Date:
July 04, 1985
Filing Date:
August 01, 1984
Export Citation:
Assignee:
MEKATORON SYSTEMS INC
International Classes:
G05B19/21; H03K5/1252; (IPC1-7): H03K5/00
Attorney, Agent or Firm:
Masaki Yamakawa