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31. 发明专利

JPH02241393A ROTATION CONTROL SYSTEM FOR DOUBLE-SPEED COOLING FAN 失效
公开(公告)号：JPH02241393A
公开(公告)日：1990-09-26
申请号：JP6283589
申请日：1989-03-15
申请人： FUJITSU LTD
发明人： HIRATSUKA YOSHIAKI
IPC分类号： F04D27/00 , H02P6/06 , H02P6/08
摘要： PURPOSE:To eliminate heat generation of a load at the time of rotation at a low speed and to reduce noise of a driving voltage line by providing a converter for shortening an ON duty zone of paired pulses from a Hall element detector in a continuous state. CONSTITUTION:In a rotation control system of a cooling fan for controlling to switch driving elements 31, 32 of exciting coils 21, 22 with an output of a Hall element detector 4 for detecting paired reverse pulses by a Hall element corresponding to N-, S-poles of a pulse motor, a converter 11 for shortening ON duty zone of paired pulses from the detector 4 in a continuous state is provided. If switching times of switching signals of the driving elements 31, 33 remain as they are, a high speed rotation is obtained, while if a switching time is reduced by half by utilizing a different value between a triangular waveform and an intermediate level is given, a low speed rotation is obtained.

32. 发明专利

JPH02106196A MOTOR ROTATION CONTROL SYSTEM 失效
公开(公告)号：JPH02106196A
公开(公告)日：1990-04-18
申请号：JP25638688
申请日：1988-10-12
申请人： FUJITSU LTD
发明人： HIRATSUKA YOSHIAKI
IPC分类号： H02P7/29
摘要： PURPOSE:To reduce noise, to decrease irregularities in the rotating speed of a fan and to enhance its efficiency by controlling a current returned to a coil by switch means to increase or decrease a counterelectromotive force generated in the coil, and controlling the torque of a motor. CONSTITUTION:A speed switching signal RS is output at a high level at the time of high temperature to turn ON a Tr 4, a low level voltage dropped by a resistor R1 is input to turn OFF a Tr 3. When a Tr 1 or Tr 2 is turned OFF, large currents flow due to counterelectromotive forces induced in coils L1 and L2, and a motor rotates at a high speed. The signal RS is output at a low level at the time of ordinary temperature to turn OFF the Tr 4, and the Tr 3 inputs a high level voltage to be turned ON. When the Tr 1 or Tr 2 is turned OFF, a current determined by the Zener voltages of Zener diodes Dz1 and Dz2 of the current determined by a counterelectromotive force induced in the coil L1 or L2 is returned through the Dz2 to the coil L1 or L2 to reduce the counterelectromotive force, thereby reducing the rotating speed of the motor.

33. 发明专利

JPH0223408A ROTATION CONTROL SYSTEM FOR COOLING FAN 失效
公开(公告)号：JPH0223408A
公开(公告)日：1990-01-25
申请号：JP17427988
申请日：1988-07-13
申请人： FUJITSU LTD
发明人： HIRATSUKA YOSHIAKI
IPC分类号： G05D23/00 , H02P7/00 , H02P25/098 , H02P29/00 , H02P29/60
摘要： PURPOSE:To fix a wind quantity at the time of a low temperature and to improve the quality of a system by rotating a fan for cooling at a high speed at the time of turning on the power source, and obtaining and controlling the number of rotations at the time of the low temperature based on the number of the rotations at the time of the high speed. CONSTITUTION:When power source 400 is turned on, a microprocessor 210 rotates a fan 100 for cooling at a high speed, reads the number of the rotations and judges the type of the fan. Thereafter, when a temperature instructing signal from a temperature sensor 300 shows the low temperature, the number of the rotations of the fan 100 is controlled so that the wind flow in the device can be fixed based on the type of the fan. Thus, even when the cooling fan used is different, the system down, etc., due to heating are prevented and the quality of a system is improved.

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