Title:
ELECTROSTATIC CAPACITY TYPE ELECTRONIC BALANCE
Document Type and Number:
Japanese Patent JPH01165920
Kind Code:
A
Abstract:
PURPOSE:To enhance measuring accuracy by removing the effect due to the change rate of oscillation frequency by alternately outputting different frequencies from an oscillation circuit, by alternately connecting two condensers to the oscillation circuit by a condenser change-over means. CONSTITUTION:The first and second condensers C1, C2 respectively constituted of electrode plates 18, 21 and 19, 21 are differentially changed in capacity each other by the displacement generated by the deformation of a strain generating body 13 by a load W. An oscillation circuit 31 is constituted of said condensers C1, C2, operational amplifiers 32, 33 and a change-over switch 34. The switch 34 is constituted so that the condensers C1, C2 are alternately connected to the circuit 31 at a predetermined time interval by a microprocessor 18 and two frequencies are outputted each time. The microprocessor 38 alternately takes in said frequencies and calculates the difference between and sum of two kinds of frequencies before and after said condensers C1, C2 are changed over and the difference is divided by the sum to calculate a weighted value.
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Inventors:
MURAKOSO TOSHIYUKI
SATO SHOICHI
YAGI MOTOI
SATO SHOICHI
YAGI MOTOI
Application Number:
JP32374187A
Publication Date:
June 29, 1989
Filing Date:
December 23, 1987
Export Citation:
Assignee:
TOKYO ELECTRIC CO LTD
International Classes:
G01D5/24; G01B7/00; G01G3/00; G01G7/06; (IPC1-7): G01B7/00; G01D5/24; G01G3/00
Domestic Patent References:
| JPS59168329A | 1984-09-22 |
Attorney, Agent or Firm:
Takehiko Suzue (2 outside)