System for and method of controlling standby power

• US 20030214825A1
• Filed: 10/15/2002
• Published: 11/20/2003
• Est. Priority Date: 05/15/2002
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Seung-Kwan
• Granted Patent: US 6,909,621 B2
• Time in Patent Office: Days
• US Class Current: 363/84
• CPC Class Codes: H02M 1/0012 Control circuits using digital or numerical techniques in DC/DC converters H02M3/157, H02M3/33515; in DC-AC converters H02M7/53873
• CPC Class Codes: H02M 1/0032 Control circuits allowing low power mode operation, e.g. in standby mode
• CPC Class Codes: H02M 7/12 using discharge tubes with control electrode or semiconductor devices with control electrode
• 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: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y04S 20/20 End-user application control systems

Abstract

An apparatus for and a method of controlling standby power to minimize energy consumption in a standby mode. The standby power control apparatus includes a control unit, a power supply unit, a constant voltage unit, and a standby power generation unit. The control unit controls an overall operation of the system. The power supply unit converts an alternating current (AC) power into a direct current (DC) voltage and outputs the DC voltage to a load. The constant voltage unit drops the output DC voltage of the power supply unit and provides the control unit with the dropped output voltage. The standby power generation unit drops the output voltage of the power supply unit from a first value to a second value lower than the first value if the system is switched to a standby mode.

Claims

1. An apparatus for controlling standby power of a system, the apparatus comprising:

a control unit which controls an overall operation of the system;

a power supply unit which converts an Alternating Current (AC) voltage into a Direct Current (DC) voltage and outputs the DC voltage to a load;

a constant voltage unit which drops the DC output voltage of the power supply unit and provides the control unit with the dropped output voltage; and

a standby power generation unit which drops the DC output voltage of the power supply unit from a first value to a second value lower than the first value if the system is switched to a standby mode.

2. The apparatus according to claim 1, wherein the power supply unit is a Switching Mode Power Supply (SMPS).

3. The apparatus according to claim 1, wherein the DC output voltage of the power supply unit is fed back into the power supply unit through the standby power generation unit, and a value of the output voltage of the power supply unit is restricted by a voltage fed back by the standby power generation unit.

4. The apparatus according to claim 1, wherein the second value equals the dropped output voltage of the constant voltage unit.

5. The apparatus according to claim 1, further comprising:

a feedback control unit which stops an operation of the power supply unit if the output DC voltage of the power supply unit exceeds a preset reference value; and

wherein the standby power generation unit comprises;

a voltage dropping element which drops the output DC voltage of the power supply unit to the second value where the system is in the standby mode, and

a switching element which feeds back the output DC voltage of the power supply to the feedback control unit by being turned on by the control unit where the system is in the standby mode.

6. The apparatus according to claim 5, wherein the voltage dropping element comprises a constant voltage element.

7. The apparatus according to claim 5, wherein the constant voltage element comprises a zener diode.

8. The apparatus according to claim 6, wherein a rated voltage of the zener diode has a value between an operating voltage of the control unit and the first value.

9. The system according to claim 1, further comprising:

an AC power detection unit which receives the AC power and observes whether the AC power is normal; and

a power cutoff unit which cuts off the AC power input to the AC power detection unit.

10. The apparatus according to claim 9, wherein the power cutoff unit comprises a bi-directional switch serially connected with an input of the AC power detection unit, the bi-directional switch being activated where the system is in a normal operation mode and being inactivated where the system is in the standby mode.

11. The apparatus according to claim 10, wherein the bi-directional switch comprises:

a light emitting device which electrically conducts and emits light where the system is in the normal operation mode; and

a photosensitive bi-directional switch element which electrically conducts in response to the emitted light.

12. The apparatus according to claim 11, wherein the light emitting device comprises a photodiode and the bi-directional switch element comprises a bi-directional three-terminal thyristor.

13. The apparatus according to claim 12, wherein:

the photodiode is supplied at an anode with the output DC voltage and grounded at a cathode through a transistor, and the transistor is turned on where the system is in the normal operation mode so the photodiode electrically conducts and is turned off where the system is in the standby mode so the photodiode does not electrically conduct.

14. The apparatus according to claim 13, wherein the turning on/off of the transistor is controlled by the control unit.

15. A method of controlling standby power in a system, the system comprising a control unit for controlling an overall operation of the system, a power supply unit for converting AC power and outputting a first DC voltage, and a constant voltage unit for dropping the first DC voltage to a second DC voltage, the method comprising:

counting an operation stopping time of the system if the operation of the system is stopped; and

if the operation stopping time of the system exceeds a preset reference time, converting an operation mode of the system into a standby mode and dropping a value of the first DC voltage to a value of the second DC voltage.

16. The method according to claim 15, further comprising:

resetting data relating to the standby mode if the system is restarted and is switched to the normal operation mode.

17. The method according to claim 15, wherein:

the system further comprises an AC power detection unit for observing whether AC power input to the system is normal, and

the method further comprises cutting off the AC power input to the AC power detection unit where the system is in the standby mode.

18. An apparatus for controlling standby power of a system, the apparatus comprising:

a control unit which controls an overall operation of the system;

a power supply unit which receives an input voltage and outputs a first Direct Current (DC) voltage and supplies the first DC voltage to a load;

a power detection unit which monitors a characteristic of the input power, a constant voltage unit which regulates the first DC voltage to a second DC voltage and outputs the second DC voltage to the control unit;

a standby power generation unit which controls the power supply unit to change a value of the first DC voltage to a value of the second DC voltage if the system is switched to a standby mode; and

a power cutoff unit which cuts off power to the power detection unit if the system is switched to the standby mode.

19. The apparatus of claim 18, wherein:

the power cutoff unit comprises a light coupled bi-directional thyristor which interrupts power to the power detection unit in response to a control signal; and

the control unit outputs the control signal where the system is switched to the standby mode.

20. The apparatus of claim 19, further comprising a transistor which functions as a buffer between the control unit and the light coupled bi-directional thyristor.