Title:
WEIGHT SENSOR
Document Type and Number:
Japanese Patent JPH02242125
Kind Code:
A
Abstract:
PURPOSE:To obtain a small sensor with a simple construction by making an electromagnet with a tray float above a fixed electromagnet as opposed thereto to measure a load based on a variation of an applied voltage of the electromagnet when an interval therebetween is controlled constant. CONSTITUTION:An electromagnet 8 is fixed on the bottom of a holder 10 and an electromagnet 9 with a tray is floated. When an object is placed on the tray 11, the electromagnet 9 is displaced so that an electrostatic capacitance tends to change between electrode plates 12 and 13 provided on the electromagnets 8 and 9. This change is detected by an electronic circuit 14 to control a voltage so that an interval of electrode plates 12 and 13 will not change to increase magnetic forces of the electromagnets 8 and 9. As a result, a load working on the tray 11 is indicated on a weight indicator 15 from a change in the voltage corresponding to an increment of the magnetic forces. This enables a measurement without any mechanical displacement between the initial state and a state after the application of a load thereby producing a simple and small sensor.
Inventors:
HOSOMI FUMIO
Application Number:
JP6243089A
Publication Date:
September 26, 1990
Filing Date:
March 15, 1989
Export Citation:
Assignee:
MATSUSHITA ELECTRIC IND CO LTD
International Classes:
G01G7/04; (IPC1-7): G01G7/04
Attorney, Agent or Firm:
Shigetaka Awano (1 person outside)