Switching mode power supply apparatus

Patent metadata

Field	Value
Publication number	US-9252668-B2
Application number	US-201213691409-A
Country	US
Kind code	B2
Filing date	Nov 30, 2012
Priority date	Dec 1, 2011
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

A switching mode power supply apparatus is provided. The switching mode power supply apparatus may include a switch unit configured to switch an input voltage to a transformer and a controller configured to select an operation mode having a switching frequency according to a size of a load applied to a secondary side of the transformer and control a switching operation of the switch unit. The switching mode power supply apparatus may include a transformer. A refrigerator having the switching mode power supply apparatus is also provided.

First claim

What is claimed is:

1. A switching mode power supply apparatus comprising:
a switch unit configured to switch an input voltage to a transformer; and
a controller configured to select an operation mode having a switching frequency according to a magnitude of a load applied to a secondary side of the transfoiiner and control a switching operation of the switch unit,
wherein the controller includes a load detection module configured to detect a load applied to the secondary side of the transformer according to a feedback signal,
wherein the controller outputs a control signal for controlling the switching operation of the switch unit in either one of a burst mode or a pulse width modulation (PWM) mode according to a magnitude of a low load when the magnitude of the load is determined as the low load, and outputs a control signal for controlling the switching operation of the switch unit in a quasi-resonant mode when the magnitude of the load is determined to be above a medium load, and
wherein the controller outputs a control signal for controlling the switching operation of the switch unit in the burst mode when the magnitude of the load is within a region representing a smallest load, outputs the control signal for controlling the switching operation of the switch unit in the PWM mode when the magnitude of the load is greater than the region representing the smallest load and less than a magnitude of the medium load, and outputs the control signal for controlling the switching operation of the switch unit in the quasi-resonant mode when the magnitude of the load is greater than a magnitude of the medium load.

2. The switching mode power supply apparatus of claim 1 , wherein the controller includes a variable oscillation module configured to determine an optimal switching frequency for the switching frequency according to the magnitude of the load applied to the secondary side of the transformer.

3. The switching mode power supply apparatus of claim 2 , wherein the controller selects the operation mode from one of the burst mode, the PWM mode, and the quasi-resonant mode according to the optimal switching frequency and the magnitude of the load determined by the variable oscillation module to repeatedly turn on and off a switch provided in the switch unit.

4. The switching mode power supply apparatus of claim 1 , wherein the controller outputs a control signal for controlling the switching operation of the switch unit in the burst mode when the magnitude of the load is less than 7 W, outputs the control signal for controlling the switching operation of the switch unit in the PWM mode when the magnitude of the load is greater than 7 W and less than 15 W, and outputs the control signal for controlling the switching operation of the switch unit in the quasi-resonant mode when the magnitude of the load is greater than 15 W.

5. The switching mode power supply apparatus of claim 1 , wherein a switching frequency of the switch unit operated with the PWM mode is lower than a switching frequency of the switch unit operated with the quasi-resonant mode when the magnitude of the load is greater than the region representing the smallest load and less than a magnitude of the medium load, and
wherein a switching frequency of the switch unit operated with the quasi-resonant mode is lower than a switching frequency of the switch unit operated with the PWM mode when the magnitude of the load is greater than a magnitude of the medium load.

6. The switching mode power supply apparatus of claim 1 , wherein the switch unit is configured to be connected to a primary side of the transformer to switch a voltage induced to the secondary side of the transformer according to a control signal of the controller.

7. The switching mode power supply apparatus of claim 1 , further comprising:
a rectifier unit configured to rectify a voltage induced to the secondary side of the transformer; and
a smoothing unit configured to smooth the rectified voltage.

8. The switching mode power supply apparatus of claim 1 , wherein the switch unit includes at least one transistor.

9. A switching mode power supply apparatus comprising:
a transformer having a primary side and a secondary side;
a capacitor for storing voltage at the primary side of the transformer;
a switch unit configured to switch a voltage stored in the capacitor provided at the primary side of the transformer to the secondary side of the transformer;
a controller configured to at least detect a magnitude of a load applied to the secondary side of the transformer, and control the switching operation of the switch unit in a burst mode or a pulse width modulation (PWM) mode when the detected magnitude of the load is a low load and to control the switching operation of the switch unit in a quasi-resonant mode when the detected size of the load is above a medium load; and
a driving circuit connected to the secondary side of the transformer,
wherein the controller includes a load detection module configured to detect the load applied to the secondary side of the transformer according to a feedback signal,
wherein the controller outputs a control signal for controlling the switching operation of the switch unit in one of the burst mode or PWM mode according to the magnitude of the low load when the magnitude of the load is determined as the low load, and outputs a control signal for controlling the switching operation of the switch unit in the quasi-resonant mode when the magnitude of the load is determined to be above the medium load, and
wherein the controller outputs a control signal for controlling the switching operation of the switch unit in the burst mode when the magnitude of the load is within a region representing a smallest load, outputs the control signal for controlling the switching operation of the switch unit in the PWM mode when the magnitude of the load is greater than the region representing the smallest load and less than a magnitude of the medium load, and outputs the control signal for controlling the switching operation of the switch unit in the quasi-resonant mode when the magnitude of the load is greater than a magnitude of the medium load.

10. The switching mode power supply apparatus of claim 9 , wherein the controller outputs a control signal for controlling the switching operation of the switch unit in the burst mode when the magnitude of the load is less than 7 W, outputs the control signal for controlling the switching operation of the switch unit in the PWM mode when the magnitude of the load is greater than 7 W and less than 15 W, and outputs the control signal for controlling the switching operation of the switch unit in the quasi-resonant mode when the magnitude of the load is greater than 15 W.

11. The switching mode power supply apparatus of claim 9 , wherein the controller includes a variable oscillation module configured to determine an optimal switching frequency according to the magnitude of the load applied to the secondary side of the transformer, and
wherein the controller selects one of the burst mode, the PWM mode, and the quasi-resonant mode according to the optimal switching frequency and the magnitude of the load determined by the variable oscillation module to repeatedly turn on and off a switching means provided in the switch unit.

12. The switching mode power supply apparatus of claim 11 , wherein a switching frequency of the switch unit operated with the PWM mode is lower than a switching frequency of the switch unit operated with the quasi-resonant mode when the magnitude of the load is greater than the region representing the smallest load and less than a magnitude of the medium load, and
wherein a swit

Assignees

• Lg Electronics Inc

Inventors

• Hu Jinseok
• Kang Kyelyong
• Park Shinhyun
• Park Gunil
• Ahn Buhwan
• Kim Jaemin

Classifications

• H02M3/33523 Primary

  with galvanic isolation between input and output of both the power stage and the feedback loop · CPC title

• H02M3/24 Primary

  by static converters · CPC title

• Y02B70/16

  Cross-Sectional Technologies · mapped topic

• H02M2001/0032

  Electricity · mapped topic

• Y02B70/1433

  Cross-Sectional Technologies · mapped topic