Title:
SWITCH POWER SUPPLY HAVING ACTIVE POWER FACTOR CORRECTION
Document Type and Number:
WIPO Patent Application WO/2017/124748
Kind Code:
A1
Abstract:
A switch power supply having active power factor correction comprises a power factor correction (PFC) circuit, a filter circuit, a main power stage, a first capacitor (C1), and an indicating circuit. An alternating-current input (IN) is connected to the first capacitor by means of the PFC circuit and is connected to the filter circuit by means of the indicating circuit. The indicating circuit consists of a light emitting diode (LED) having a unilateral conduction function and an inductor (L); and a current direction of the PFC circuit supplying power to the main power stage by means of the inductor is opposite to a conduction direction of the LED. The LED may also be an optical coupling light emitting device. The filter circuit at least comprises an electrolytic capacitor (c2). When the electrolytic capacitor is normal, an excitation current of the main power stage basically does not appear in the inductor and the LED does not emit light. When the equivalent series resistance (ESR) of the electrolytic capacitor sharply rises, the excitation current appears in the inductor. When a power transistor in the main power stage is switched off, the excitation current in the inductor cannot be abruptly changed; instead, the excitation current passes through the LED for implementing a follow current and enables the LED to emit light, so that a user is prompted that the circuit electrolytic capacitor may have the risk of complete failure. The switch power supply has low additional cost and unchanged efficiency and is easy to implement.
Inventors:
WANG BAOJUN (CN)
Application Number:
PCT/CN2016/097138
Publication Date:
July 27, 2017
Filing Date:
August 29, 2016
Export Citation:
Assignee:
MORNSUN GUANGZHOU SCIENCE & TECH LTD (CN)
International Classes:
H02M1/42; H02M7/217; H02M3/335; H05B44/00
Foreign References:
| CN105577003A | 2016-05-11 | |||
| CN205490207U | 2016-08-17 | |||
| CN105491728A | 2016-04-13 | |||
| CN205491305U | 2016-08-17 | |||
| CN105676936A | 2016-06-15 | |||
| CN105676937A | 2016-06-15 | |||
| CN105527524A | 2016-04-27 | |||
| CN103605084A | 2014-02-26 | |||
| CN103390879A | 2013-11-13 | |||
| JP2012142132A | 2012-07-26 |
Attorney, Agent or Firm:
GUANGZHOU ZHIYOU PATENT & TRADEMARK AGENCY CO., LTD (CN)
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