Electronic power-saving power control circuit

• US 6,982,858 B2
• Filed: 04/29/2003
• Issued: 01/03/2006
• Est. Priority Date: 04/29/2003
• Status: Expired due to Fees

• Current Assignee: Digitek Technologies Co., Ltd.
• Original Assignee: Digitek Technologies Co., Ltd.
• Inventors: Shih, Te-Fu
• Primary Examiner(s): LEJA, RONALD W
• Application Number:
  US10/424,805
• Publication Number:
  US 20040218325A1
• Time in Patent Office: 980 Days
• Field of Search: 361/93.1, 323/237, 323/905
• US Class Current: 361/93.1
• CPC Class Codes: H02H 3/08 responsive to excess current responsive to abnormal temperature caused by excess current H02H5/04
• CPC Class Codes: H02M 1/0032 Control circuits allowing low power mode operation, e.g. in standby mode
• CPC Class Codes: H02M 5/2576 with digital control
• CPC Class Codes: H05B 41/3924 by phase control, e.g. using a triac H05B41/3922 takes precedence
• 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: Y10S 323/905 Lamp dimmer structure

Abstract

An electronic power-saving power control circuit for connection between a single-phase power supply and a lighting fixture to control the output of power supply to the lighting fixture is disclosed to include a CPU (central processing unit), a power voltage detector, a silicon controlled semiconductor circuit, a current phase detector, a trigger circuit, a resistor, a current detector, and a DC power supply circuit. The electronic power-saving power control circuit saves the consumption of power supply by dropping the voltage without affecting normal working of the lighting fixture at the load and, achieves an overcurrent protection.

Claims

1. Art electronic power-saving power control circuit connected between a single-phase power supply and a lighting fixture for controlling the output of power supplied to the lighting fixture, comprised of a CPU (central processing unit), a power voltage detector, a silicon controlled semiconductor circuit, a current phase detector, a trigger circuit, a resistor, a current detector, and a DC power supply circuit, wherein:

said CPU is a control center of the power-saving power control circuit, and adapted to turn on said silicon controlled semiconductor circuit responsive to a triggering angle required for a predetermined voltage drop and a time in which an electric current detected by said current phase detector is zeroed when a power voltage from said power voltage detector is received, causing said silicon controlled semiconductor circuit to provide a power output to said lighting fixture, said CPU controlling said silicon controlled semiconductor circuit to first provide a full operating voltage to said lighting fixture for a time period established to ensure initiation thereof and then gradually reduce the operating voltage to avoid a sharp change in light output of said lighting fixture;

said voltage detector detects a voltage level of said single-phase power supply, providing a detection result to said CPU;

said silicon controlled semiconductor circuit is a circuit formed of a silicon controlled semiconductor and a protection circuit and connected in series between said single-phase power supply and said lighting fixture for working with said current phase detector and said trigger circuit to control power output to said lighting fixture;

said current phase detector detects the time where the electric current passing through said silicon controlled semiconductor is zeroed, and provides detection information to said CPU for triggering said silicon controlled semiconductor;

said trigger circuit is adapted to trigger said silicon controlled semiconductor circuit for output of power to said lighting fixture responsive to control by said CPU;

said resistor is electrically connected between said single-phase power supply and said lighting fixture, and adapted to cause a voltage drop responsive to passage of a load current therethrough;

said current detection circuit detects the value of a voltage drop across said resistor and provides a corresponding measured current value to said CPU.

2. The electronic power-saving power control circuit as claimed in claim 1, the relationship between said triggering angle and said voltage drop is not a linearity.

3. The electronic power-saving power control circuit as claimed in claim 1, wherein said triggering angle and said voltage drop are defined within a limited range subject to the nominal voltage and the features of said lighting fixture.

4. The electronic power-saving power control circuit as claimed in claim 1, wherein said current detection circuit detects the level of the electric current subject to the voltage drop at said resistor, so that said CPU drives said silicon controlled semiconductor circuit to stop power supply from said lighting fixture when the level of the electric current detected by said current detection circuit surpassed the nominal current, achieving an overcurrent protection.