Title:
WATER LEVEL CONTROLLER
Document Type and Number:
Japanese Patent JP3614285
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To prevent the erroneous detection of a water level with a simple circuit constitution by adding a half-wave rectifier circuit to the input side of a water level detector to supply a current to a current detection circuit only when the AC power supply connection side of the water level detection circuit is set at a negative voltage level and accordingly actuating only the circuit that detected the water.
SOLUTION: If a terminal 31 of an AC power supply 3 is set at a negative voltage level when the water 10 is set at a level 12, a current successively flows to an AC power supply terminal 32, a water level detection electrode 21, the water 10, a water level detection electrode 22, a diode 41 and then a capacitor 43 and also flows to a resistance 44 and then to an AC power supply terminal 31 respectively. Thus, an FET 47 is turned on via a resistance 46. If the terminal 31 of the power supply 3 is set at a positive voltage level, the current successively flows to the terminal 31, a resistance 45, a diode 42, the electrode 22, the water 10, the electrode 21 and then the terminal 32. Thus, the FET 47 is not turned on. As a result, a water detection circuit 4 operates only when the terminal 31 is set at a negative voltage level. Meanwhile, a water level detection circuit 5 does not operate.
Inventors:
Yasuhisa Enomoto
Kimura Kazumasa
Kimura Kazumasa
Application Number:
JP27941697A
Publication Date:
January 26, 2005
Filing Date:
September 29, 1997
Export Citation:
Assignee:
Toyo Denki Manufacturing Co., Ltd.
International Classes:
G05D9/12; (IPC1-7): G05D9/12
Domestic Patent References:
| JP8159845A |
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