Fluid flow rate measuring device and water meter
AssigneeSemiconductor Components Industries, LLC
InventorsHideo KONDO, Yoshiaki YONEZAWA
Life of this patent
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Abstract
There is offered a water meter that requires no coil so that its cost is reduced. The water meter is formed to include an impeller, a rotation reduction unit, a first circular plate, a second circular plate, a rotation detection unit and an arithmetic unit. The rotation detection unit forms first, second and third combination capacitors with a switching circuit. The rotation detection unit detects changes in capacitances of the first, second and third combination capacitors associated with a rotation of the first circular plate. The arithmetic unit is configured so as to electrically detect the rotation angle θ of the first circular plate based on the changes in the capacitances.
Claims20
A fluid flow rate measuring device comprising:
- a first circular plate comprising a fan-shaped common capacitor electrode disposed on a principal of the first circular plate surface and an insulator portion disposed on the rest of the principal surface;
- a rotation device rotating the first circular plate at a rotation speed proportional to a flow rate of a fluid;
- a second circular plate superposed above the principal surface of the first circular plate with a certain space therebetween and comprising a first, a second and a third fan-shaped capacitor electrodes disposed on a principal surface of the second circular plate point-symmetrically with respect to a center of its principal surface;
- and
- a rotation detection unit detecting a capacitance of each of first, second and third capacitors each formed between the common capacitor electrode and each of the first, second and third capacitor electrodes, respectively.
A fluid flow rate measuring device comprising:
- a first circular plate comprising a fan-shaped common capacitor electrode disposed on its principal surface and insulator portion disposed on the rest of the principal surface;
- a rotation device rotating the first circular plate at a rotation speed proportional to a flow rate of a fluid;
- a second circular plate superposed above the principal surface of the first circular plate with a certain space therebetween and comprising first, second and third fan-shaped capacitor electrodes disposed on its principal surface point-symmetrically with respect to a center of its principal surface;
- a rotation detection unit detecting a capacitance of each of first, second and third capacitors each formed between the common capacitor electrode and each of the first, second and third capacitor electrodes, respectively;
- and
- an arithmetic unit calculating the rotation speed of the first circular plate based on the capacitance of each of the first, second and third capacitors, and calculating the flow rate of the fluid based on the rotation speed.
A water meter comprising:
- a first circular plate comprising a fan-shaped common capacitor electrode disposed on a principal of the first circular plate surface and an insulator portion disposed on the rest of the principal surface;
- a rotation device rotating the first circular plate at a rotation speed proportional to a flow rate of water;
- a second circular plate superposed above the principal surface of the first circular plate with a certain space therebetween and comprising a first, a second and a third fan-shaped capacitor electrodes disposed on a principal surface of the second circular plate point-symmetrically with respect to a center of its principal surface;
- and
- a rotation detection unit detecting a capacitance of each of first, second and third capacitors each formed between the common capacitor electrode and each of the first, second and third capacitor electrodes, respectively.
Dependencies are inferred from the claim text.