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Patent Searching and Data


Title:
CONTROL CIRCUIT FOR DC MOTOR
Document Type and Number:
Japanese Patent JPH07194163
Kind Code:
A
Abstract:

PURPOSE: To simplify a control circuit for a DC motor so that the scale of the circuit can be reduced by generating a constant voltage having a prescribed negative temperature coefficient from a constant-voltage generating circuit and giving an input offset voltage with a positive temperature coefficient having the same absolute value as the negative temperature coefficient of the constant voltage to a reference current generating circuit.

CONSTITUTION: A control circuit for DC motor is provided with a constant- voltage generating circuit 21, reference current generating circuit A1 which generates a reference current Irf based on a reference current generating voltage Vrf obtained by amplifying the constant-voltage V1 of the circuit 21, and rotating speed control circuit 26 which controls the rotating speed of a DC motor 36 based on the reference current Irf. In such a control circuit, the circuit 21 generates the constant voltage V1 having a prescribed negative temperature coefficient. The circuit A1 has an input circuit composed of differential paired transistors, to the emitters of which a current ratio per unit area is set, so that the circuit A1 can have an input offset voltage with a positive temperature coefficient having the same absolute value as the negative temperature coefficient of the voltage V2 has.


Inventors:
TERADA YUKIHIRO
Application Number:
JP33156493A
Publication Date:
July 28, 1995
Filing Date:
December 27, 1993
Export Citation:
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Assignee:
MITSUMI ELECTRIC CO LTD
International Classes:
H02P7/06; H02P7/00; H02P7/288; (IPC1-7): H02P5/168; H02P5/06
Attorney, Agent or Firm:
Tadahiko Ito