Switching power supply apparatus including controller that switches a switching unit based on the amount of charge in a charge unit

• US 9,473,030 B2
• Filed: 07/28/2014
• Issued: 10/18/2016
• Est. Priority Date: 02/03/2012
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Hosotani, Tatsuya
• Primary Examiner(s): Dole, Timothy J
• Assistant Examiner(s): AHMED, YUSEF A
• Application Number:
  US14/444,054
• Publication Number:
  US 20140334185A1
• Time in Patent Office: 813 Days
• US Class Current: 1/1
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: H02M 1/0032 Control circuits allowing low power mode operation, e.g. in standby mode
• CPC Class Codes: H02M 1/0048 Circuits or arrangements for reducing losses using snubbers H02M1/34
• CPC Class Codes: H02M 3/24 by static converters
• CPC Class Codes: H02M 7/2176 comprising a passive stage to generate a rectified sinusoidal voltage and a controlled switching element in series between such stage and the output
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A switching power supply apparatus includes an isolated converter that has efficiency characteristics in which power conversion efficiency at a rated load is higher than power conversion efficiency at a light load and that converts power-supply voltage into direct-current voltage to output the direct-current voltage; an FET that switches supply and shutoff of the power-supply voltage to the isolated converter; a secondary battery that stores the direct-current voltage output from the isolated converter; a voltage detector that detects an amount of charge in the secondary battery; and a controller that switches the FET on the basis of the amount of charge in the secondary battery.

Claims

1. A switching power supply apparatus comprising:

a converter circuit configured to have efficiency characteristics in which power conversion efficiency at a rated load is higher than power conversion efficiency at a light load and that converts power-supply voltage into direct-current voltage to output the direct-current voltage;

a switching unit configured to switch supply and shutoff of the power-supply voltage to the converter circuit, such that when the switching unit is switched to shut off the power-supply voltage to the converter circuit, the power-supply voltage is prevented from being input to the converter circuit;

a charge unit configured to store the direct-current voltage output from the converter circuit;

a detecting unit configured to detect an amount of charge in the charge unit; and

a controller configured and programmed to switch the switching unit based on the amount of charge detected by the detecting unit;

wherein

the controller is configured and programmed to set the switching unit to the shutoff state if the amount of charge in the charge unit is higher than a first threshold value and set the switching unit to the supply state if the amount of charge in the charge unit is lower than a second threshold value;

the controller is configured and programmed to output the direct-current voltage subjected to the conversion in the converter circuit and store the direct-current voltage subjected to the conversion in the converter circuit in the charge unit when the switching unit is in the supply state and output the direct-current voltage stored in the charge unit when the switching unit is in the shutoff state; and

a frozen period in which the switching unit is in the shutoff state is controlled depending on an increase and a decrease of output power and the frozen period is lengthened with the decreasing output power.

2. The switching power supply apparatus according to claim 1, further comprising a voltage conversion unit configured to perform voltage conversion of the direct-current voltage output from the charge unit.

3. The switching power supply apparatus according to claim 2, wherein the voltage conversion unit is a DC-DC converter.

4. The switching power supply apparatus according to claim 1, wherein the switching unit is a transistor.

5. The switching power supply apparatus according to claim 1, wherein the switching unit is a mechanical switch.

6. The switching power supply apparatus according to claim 1, wherein the charge unit is a secondary battery.

7. The switching power supply apparatus according to claim 1, wherein the charge unit is a capacitor.

8. The switching power supply apparatus according to claim 7, wherein the charge unit is an electric double layer capacitor.

9. The switching power supply apparatus according to claim 1, wherein the converter circuit includes a synchronous rectifier circuit.

10. The switching power supply apparatus according to claim 1, wherein

the converter circuit is an isolated converter including an isolated transformer;

and

the controller is provided at a primary side of the converter circuit.

11. The switching power supply apparatus according to claim 1, wherein

the converter circuit is an isolated converter including an isolated transformer;

and

the controller is provided at a secondary side of the converter circuit.

12. The switching power supply apparatus according to claim 1, wherein the converter circuit includes two isolated converters.

13. The switching power supply apparatus according to claim 12, wherein the two isolated converters are isolated DC-DC converters including a switching transformer.

14. The switching power supply apparatus according to claim 1, further comprising an electromagnetic interference filter, a diode bridge circuit, an n-type metal oxide semiconductor field effect transistor, and a power factor correction converter at a primary side.

15. The switching power supply apparatus according to claim 1, further comprising a secondary battery, a post regulator, an n-type metal oxide semiconductor field effect transistor, a voltage detector, a current detector, and the controller at a secondary side.