Title:
ACCURACY ADJUSTMENT SYSTEM FOR A/D CONVERTER CIRCUIT
Document Type and Number:
Japanese Patent JP3114541
Kind Code:
B2
Abstract:
PURPOSE: To adjust entire accuracy automatically by storing a correction count of input data with respect to a theoretical value into a CPU and correcting the input data at all times.
CONSTITUTION: In the case of automatic adjustment, a switch SW1 is thrown to the position of an A/D accuracy monitoring voltage setting device 12 and a switch SW2 is thrown to the position of an amplifier 11. Then an A/D accuracy monitoring voltage of a voltage setting device 12 is given to a reference input channel (0) of a multiplexer 4 by the switch SW1 and a harmonic from an internal oscillator 7 is given to an amplifier 11 by the switch SW2. The amplifier 11 amplifies the harmonics and gives the result to an input channel (1-n) of the multiplexer 4 through auxiliary transformers 11-1n. and filters 21-2n. The voltage is selected by the multiplexer 4 and each analog signal is converted into a digital signal by an A/D converter 5. A CPU 6 compares an input voltage with an A/D conversion result to use a difference from a theoretical value as a correction coefficient. Then the coefficient is used to correct input data.
Inventors:
Futai Furuse
Toshiro Fujimoto
Toshiro Fujimoto
Application Number:
JP31956094A
Publication Date:
December 04, 2000
Filing Date:
December 22, 1994
Export Citation:
Assignee:
KABUSHIKI KAISHA MEIDENSHA
International Classes:
G01R35/00; G01R19/00; H02H3/02; H03M1/10; (IPC1-7): H03M1/10; G01R19/00; G01R35/00; H02H3/02
Domestic Patent References:
| JP63222516A |
Attorney, Agent or Firm:
Fujiya Shiga (1 person outside)