Power regulator employing a sinusoidal reference

• US 6,407,515 B1
• Filed: 11/12/1999
• Issued: 06/18/2002
• Est. Priority Date: 11/12/1999
• Status: Expired due to Fees

• Current Assignee: Sinewave Energy Technologies, LLC
• Original Assignee: Lighting Control, Inc.
• Inventors: Lindauer, Louis F., Hesler, John C.
• Primary Examiner(s): Vu, David
• Application Number:
  US09/440,322
• Time in Patent Office: 949 Days
• Field of Search: 315/291, 315/294, 315/295, 315/296, 315/297, 315/312, 315/194, 315/224, 363/95, 363/34
• US Class Current: 315/294
• CPC Class Codes: H02M 5/293 using semiconductor devices only
• CPC Class Codes: H05B 41/3924 by phase control, e.g. using a triac H05B41/3922 takes precedence

Abstract

A power regulator for use with an AC power source includes a voltage converter having a first input and a second input. The first input is connected with the AC power source and receives AC current therefrom. The second input is connected to a controller and receives a control signal therefrom. The voltage converter generates a substantially sinusoidal regulator output signal, the amplitude of which is responsive to the control signal. The power regulator also includes a controller having a first input and a second input. The first input receives the regulator output signal and the second input receives a set point signal. The set point signal determines the amplitude of a substantially sinusoidal reference signal which is substantially in-phase with the regulator output signal. The controller generates the control signal indicative of the instantaneous difference between the regulator output signal and the amplitude of the substantially sinusoidal reference signal. The amplitude of the substantially sinusoidal reference signal is independent of the amplitude of the AC power source and the amplitude of the regulator output signal.

Claims

1. A power regulator for use with an AC power source comprising:

a voltage converter having a first input and a second input, the first input being connected with the AC power source and receiving AC current therefrom and the second input being connected with a controller and receiving a control signal therefrom, the voltage converter generating a substantially sinusoidal regulator output signal, the amplitude of which is responsive to the control signal; and

a controller having a first input and a second input, the first input receiving the regulator output signal and the second input receiving a set point signal, the set point signal determining the amplitude of a substantially sinusoidal reference signal, the substantially sinusoidal reference signal being substantially in-phase with the regulator output signal, the controller generating the control signal indicative of the instantaneous difference between the regulator output signal and the amplitude of the substantially sinusoidal reference signal wherein the amplitude of the substantially sinusoidal reference signal is independent of the amplitude of the AC power source and the amplitude of the regulator output signal.

2. The power regulator according to claim 1 wherein the regulator output signal is connected to at least one series combination of a core and coil ballast and an electric discharge lamp.

3. The power regulator according to claim 1 wherein the regulator output signal is connected to at least one incandescent lamp.

4. The power regulator according to claim 1 wherein the voltage converter comprises a first control circuit interrupting flow of the AC current for periods of time responsive to the control signal to generate an intermediate AC current and a filtering circuit receiving the intermediate AC current from the first control circuit and generating the regulator output signal which is smoothed relative to the intermediate AC current, the filtering circuit comprising an inductor receiving the intermediate AC current and attenuating therefrom frequency components higher than the frequency of the AC current and a second control circuit receiving the intermediate AC current and acting as an open circuit when the first control circuit is conducting the AC current and as a closed circuit when the first control circuit is interrupting flow of the AC current wherein the regulator output signal is applied to a load.

5. The power regulator according to claim 1 further comprising a reference generator.

6. The power regulator according to claim 5 wherein the reference generator comprises a look-up table storing a predetermined number of discrete values of a sinusoidal function.

7. The power regulator according to claim 5, wherein the amplitude of the substantially sinusoidal reference signal is the product of the set point signal and an output from the reference generator.

8. The power regulator according to claim 7 wherein the set point signal is generated by at least one of a sensor signal, a timer signal and a power level selector.

9. A power regulator for use with an AC power source for regulating the power applied to at least one lamp comprising:

a voltage converter having a first input and a second input, the first input being connected with the AC power source and receiving AC current therefrom, and the second input being connected with a controller and receiving a control signal therefrom, the voltage converter providing a substantially sinusoidal regulator output signal, the voltage of which being responsive to the control signal; and

a controller having a input and a second input, the first input receiving the regulator output signal and the second input receiving a set point signal, the controller generating the control signal based on a status of at least one lamp and a comparison of the voltage of the regulator output signal with a substantially sinusoidal reference signal, the amplitude of the reference signal being responsive to the set point signal and independent of the amplitude of the AC power source and the regulator output signal, the controller determining the status of the at least one lamp by comparing an output current of the regulator with at least one predetermined fault limit.

10. The power regulator according to claim 9 wherein the voltage converter comprises a first control circuit interrupting flow of the AC current for periods of time responsive to the control signal to generate an intermediate AC current and a filtering circuit receiving the intermediate AC current from the first control circuit and generating the regulator output signal which is smoothed relative to the intermediate AC current, the filtering circuit comprising an inductor receiving the intermediate AC current and attenuating therefrom frequency components higher than the frequency of the AC current and a second control circuit receiving the intermediate AC current and acting as an open circuit when the first control circuit is conducting the AC current and as a closed circuit when the first control circuit is interrupting flow of the AC current wherein the regulator output signal is applied to the at least one lamp.

11. The power regulator according to claim 9 wherein the output of the regulator is connected to at least one series combination of a core and coil ballast and an electric discharge lamp.

12. The power regulator according to claim 9 wherein the output of the regulator is connected to at least one incandescent lamp.

13. The power regulator according to claim 9 wherein the controller includes a reference generator.

14. The power regulator according to claim 13 wherein the reference generator comprises a look-up table storing a predetermined number of discrete values of a sinusoidal function.

15. The power regulator according to claim 14, wherein the amplitude of the reference signal is the product of an adjusted set point signal and an output of the reference generator.

16. The power regulator according to claim 15, the adjusted set point signal is the product of the set point signal and a ramp signal, the ramp signal being a function of at least one lamp status.

17. The power regulator according to claim 9 wherein the at least one predetermined fault limit includes an overcurrent limit and an undercurrent limit.

18. The power regulator according to claim 9 wherein the set point signal is generated by at least one of a sensor signal, a power selector responsive to an operator adjustment and a timer.

19. A method of generating a substantially sinusoidal output voltage for powering at least one lamp with a power regulator connected to an AC power source comprising the steps of:

determining a status of the at least one lamp;

generating a substantially sinusoidal reference signal responsive to a set point and the lamp status;

generating the substantially sinusoidal output voltage;

generating a control signal responsive to the difference between the substantially sinusoidal output voltage and the substantially sinusoidal reference signal such that output voltage is proportional to the substantially sinusoidal reference signal if the lamp has a regulation status;

setting the output voltage to full output if the lamp has a power-up status; and

setting the output voltage to zero if the lamp has a cool-down status.

20. A method of powering at least one lamp according to claim 19 wherein if the lamp is a high intensity discharge lamp the rate of dimming is controlled by a ramp signal.

21. A method of powering at least one lamp according to claim 19 wherein if the lamp is an incandescent lamp the rate of increased illumination is controlled by a ramp signal.

22. A method of powering at least one lamp according to claim 19 wherein the status of the at least one lamp is determined by measuring an output current of the regulator.

23. A method of powering at least one lamp according to claim 22 wherein the output current of the regulator is compared with an overcurrent limit and an undercurrent limit for determining the status of the at least one lamp.

24. A method of powering at least one lamp according to claim 19 wherein the substantially sinusoidal reference signal is substantially in phase with the output voltage.