Title:
SYSTEM HAVING CURRENT-LIMITING OUTPUT AND POWER SUPPLY CIRCUIT
Document Type and Number:
Japanese Patent JP3266679
Kind Code:
B2
Abstract:
PURPOSE: To prevent a current from increasing and to obtain accurate current- limiting characteristic by a system, wherein a sense resistor for detecting a load current is connected between a negative input and the ground, a detection voltage thereof is compared with the voltage drop of a control resistor and a switching transistor for power is turned off.
CONSTITUTION: An output current passing through a switching transistor 52 passes through a sense resistor 54, connector between the ground and a negative input and generates a sense voltage. Meanwhile, a current passing through a constant current source 56 passes through a current-limiting control resistor 58 and comes to a negative input. At the time when an opposite-end voltage value of the control resistor 58 and a sense voltage value are equal, a non- grounded input terminal of a comparator 60 is made to be at a zero volt. When the output current increases and the sense voltage rises, herein, the output of the comparator 60 turns off the transistor 52 through the intermediary of a logic block 62, so as to limit the output current. The limited value of the output current can be easily adjusted by a resistance value of the control resistor 58 or by setting of a constant-current source 56.
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Inventors:
Barbara Krishnan
Leif Oh Lund
Richard A. Keller
Leif Oh Lund
Richard A. Keller
Application Number:
JP1897093A
Publication Date:
March 18, 2002
Filing Date:
February 05, 1993
Export Citation:
Assignee:
Power Integrations, Inc.
International Classes:
H02H7/20; G05F1/563; H02M3/156; H02M3/28; H02M3/335; H03K17/082; (IPC1-7): H02M3/28; H02H7/20
Domestic Patent References:
| JP62178161A | ||||
| JP5153775A | ||||
| JP62152371A | ||||
| JP63217976A |
Attorney, Agent or Firm:
Akira Asamura (2 outside)