Title:
静電容量検出回路
Document Type and Number:
Japanese Patent JP5700138
Kind Code:
B2
Abstract:
The present invention provides a capacitance detection circuit that has a simple configuration and that is capable of preventing a decrease in insulation resistance caused by deterioration of hygroscopicity. The capacitance detection circuit has at least a carrier signal generating circuit (21) that supplies a carrier signal to one of movable and fixed electrodes; an operational amplifier (Q21) that has input terminals, with the other one of the movable and fixed electrodes of a physical sensor (1) being input to one of the input terminals while the other one of the terminals being connected to the ground; and a printed circuit board (30) on which the physical quantity sensor, the carrier signal generating circuit, and the operational amplifier are mounted. An insulation-secured area (Ais) on the printed circuit board is configured as a moisture absorption reduction area (A1), including at least an electrode connection part of the physical quantity sensor, an input-side connection part of the operational amplifier, and a connection part connected to the input side of the operational amplifier out of connection parts of input-side circuit components connected between the electrode connection part and the input-side connection part.
Inventors:
Masami Kishiro
Application Number:
JP2013545784A
Publication Date:
April 15, 2015
Filing Date:
November 19, 2012
Export Citation:
Assignee:
Fuji Electric Co., Ltd.
International Classes:
G01R27/26
Domestic Patent References:
| JP2000234939A | ||||
| JP2002256060A | ||||
| JP2008102091A | ||||
| JP62252953A | ||||
| JP2006054111A | ||||
| JP61065114A |
Attorney, Agent or Firm:
Ichi Hirose
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