JPH05292787

PURPOSE:To protect a coil against burning by shortening the charge/discharge time when a driving circuit is operating with a power supply voltage higher than a predetermined level upon occurrence of motor lock thereby reducing the duty ratio of operating and unoperating times of the driving circuit....

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Main Authors NAITO KAZUHIDE, KOMIYAMA KIKUO, UCHIDA TOSHIHIKO, KURA RYUZO, YASUMOTO KAZUHIRO, SHINODA YUKIO
Format Patent
LanguageEnglish
Published 05.11.1993
Edition5
Subjects
CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORSOR DYNAMO-ELECTRIC CONVERTERS
CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
ELECTRICITY
GENERATION
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Summary:PURPOSE:To protect a coil against burning by shortening the charge/discharge time when a driving circuit is operating with a power supply voltage higher than a predetermined level upon occurrence of motor lock thereby reducing the duty ratio of operating and unoperating times of the driving circuit. CONSTITUTION:Upon occurrence of motor lock, a position detecting means 4 has H or L level output while a discharge pulse generating circuit 14 sustains L level output and a discharging transistor(Tr) 15 is turned OFF. Consequently, a capacitor(CD) 16 is not discharged through the Tr 15 and the charging voltage thereof increases. At that time, a driving circuit 5 is operating and one of amplifiers 8, 9 has L level output and thereby a Tr 25 in a charging time shortening circuit 20 is turned ON. If the power supply voltage is higher than a predetermined level, a Zener diode 27 is conducted to feeds a charging current to the CD 16 thus shortening the charging time. When the charging voltage of the CD 16 exceeds a first potential, an output of a driving circuit control section 18 is inverted to L level thus bringing about unoperating state of the driving circuit 5.
Bibliography:Application Number: JP19920092779