Title:
BRUSHLESS MOTOR
Document Type and Number:
Japanese Patent JPS5698390
Kind Code:
A
Abstract:
PURPOSE:To reduce the capacity of a switching element by providing a protecting circuit for absorbing counter electromotive force generated at an armature coil and another protecting circuit for dropping the switching element to earth potential while the counter electromotive force is generating. CONSTITUTION:Magnetic responsive elements PS1-PS3 for detecting the rotating position of the motor control through comparators OP1-OP3 transistors TR1-TR3 and sequentially drive armature coils A1-A3, respectively. First protecting circuit 1 including a zener diode ZD is provided between the collector and the base of the transistors TR1-TR3, and the second protecting circuit 4 including transistors TR4, TR5 is provided among the comparators OP1-OP3. Accordingly, the counter electromotive forces of the armature coils A1-A3 are absorbed by the first protecting circuit 1 and are dropped to the earth by the second protecting circuit 3, and are thus effectively absorbed, and the capacity of the transistors can be reduced.
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Inventors:
NAITOU SHIYOUTAROU
TOKUYAMA KEIICHI
TOKUYAMA KEIICHI
Application Number:
JP12280A
Publication Date:
August 07, 1981
Filing Date:
January 07, 1980
Export Citation:
Assignee:
HITACHI LTD
International Classes:
H02P6/12; H02P6/00; (IPC1-7): H02P6/02