Title:
CURRENT DETECTING CIRCUIT OF SWITCHING POWER SOURCE DEVICE
Document Type and Number:
Japanese Patent JP3138992
Kind Code:
B2
Abstract:
PURPOSE: To obtain a voltage proportional to an output current of an inductance even when a DC output voltage on the secondary side of a transformer is made variable.
CONSTITUTION: A current detecting circuit 14A detects a current flowing in the primary side of a transformer 2 by a current transformer 8 and charges a current detection signal I in a capacitor 12. A change in a DC output voltage Vo is detected by a light-emitting diode 22a and a phototransistor 22b of a photocoupler 22 is connected to a discharge circuit 23. This discharge circuit 23 makes the amount of the current of a current source 24 change on the basis of an output voltage of the phototransistor 22b. Even when the DC output voltage Vo is made variable, according to this constitution, an output voltage VC of the discharge circuit 23 has virtually the same waveform as an output current IL of an inductance 6.
Inventors:
Kazufumi Watanabe
Application Number:
JP5180192A
Publication Date:
February 26, 2001
Filing Date:
March 10, 1992
Export Citation:
Assignee:
Densei-Lambda Co., Ltd.
International Classes:
H02M3/28; (IPC1-7): H02M3/28
Domestic Patent References:
| JP6216073A | ||||
| JP363080A | ||||
| JP54133320A |
Attorney, Agent or Firm:
Mamoru Ushiki