Title:
HEATER CONTROL DEVICE FOR AIR/FUEL RATIO SENSOR FOR INTERNAL COMBUSTION ENGINE
Document Type and Number:
Japanese Patent JP3385893
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To activate an air/fuel ratio sensor early when starting an engine by closing a power supply switch before closing a first switch for energizing and breaking a current that passes through a heater.
SOLUTION: A power supply consisting of a battery 2 and an alternator 20 supplies a power to a heater 1 for heating an air/fuel sensor and a power supply switch 10 opens and closes the line of the power supply. Also, a capacitor circuit 3 discharges a charge being accumulated by charging the battery with the power supply via the heater 1 and a first switch 4 energizes or breaks a current that flows to the heater 1. At this time, a controlling means 5 closes the power supply switch 10 before closing the first switch 4. More specifically, the power supply switch 10 is closed, the capacitor circuit 3 is charged, and then the first switch 4 is closed, thus supplying a power from the power supply to the heater 1 and at the same time discharging the electric charge of the capacitor circuit 3 via the heater 1. Therefore, the heater 1 can be activated at an early stage, thus activating an air/fuel sensor at an early stage when starting an engine.
Inventors:
Hiroshi Tanikawa
Application Number:
JP3794397A
Publication Date:
March 10, 2003
Filing Date:
February 21, 1997
Export Citation:
Assignee:
TOYOTA JIDOSHA KABUSHIKI KAISHA
International Classes:
G01N27/41; F02D41/14; G01N27/406; G01N27/409; G01N27/419; (IPC1-7): G01N27/409; F02D41/14; G01N27/41; G01N27/419
Domestic Patent References:
| JP3246461A | ||||
| JP711941A | ||||
| JP658140A | ||||
| JP552215U |
Attorney, Agent or Firm:
Takashi Ishida (3 others)
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