Title:
FAN DRIVE CIRCUIT WITH PROTECTIVE FUNCTION
Document Type and Number:
Japanese Patent JP3850551
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To prevent the temperature of a coil from rising abnormally, if elastic foreign matter is caught in the blade of a fan, by setting the ratio between supply and stop periods of current into the coil so as to be higher than the ratio set by the charging and discharging the currents of a charging/discharging current generating means.
SOLUTION: A rotation detecting signal from a rotation detecting means 1 for detecting the rotation of the rotor of a fan motor supplies current into the drive coil of the fan motor, and applies a drive force to the rotor of the fan motor. A capacitor discharging means 3' discharges a capacitor 4 rapidly, based on the rotation detecting signal and determines the condition of the fan motor from the terminal voltage of the capacitor to generate the condition signals of drive and stopping conditions. The capacitor discharging means 3' supplies charging current, when the condition signal is under the drive condition, discharging current when the condition signal is under the stopping condition, to the capacitor, supplies current to a coil when the condition signal is under the driving condition, and cuts off the current to the coil, when the condition signal is under the suspending condition. The condition signal is also supplied to the capacitor discharging means 3', so that the capacitor discharging means 3' enables the capacitor to be discharged, when the condition signal is under drive condition and prohibits the capacitor from being discharged under the stopping condition.
Inventors:
Kenji Oe
Application Number:
JP10860798A
Publication Date:
November 29, 2006
Filing Date:
April 03, 1998
Export Citation:
Assignee:
Nidec Corporation
International Classes:
F04D27/00; H02P7/00; H02P29/02; H02P29/024; H02P29/60; (IPC1-7): H02P7/00; F04D27/00
Domestic Patent References:
| JP9163786A | ||||
| JP62132641U | ||||
| JP4049890A | ||||
| JP4049888A |