Switching power supply with capacitor input for a wide range of AC input voltages

• US 7,362,599 B2
• Filed: 08/29/2005
• Issued: 04/22/2008
• Est. Priority Date: 12/13/2004
• Status: Active Grant

• Current Assignee: Thomas & Betts International LLC (ABB Limited)
• Original Assignee: Thomas & Betts International Incorporated (ABB Limited)
• Inventors: Rapeanu, Radu-Cornel
• Primary Examiner(s): STERRETT, JEFFREY L
• Application Number:
  US11/214,198
• Publication Number:
  US 20060126368A1
• Time in Patent Office: 967 Days
• Field of Search: 363/89
• US Class Current: 363/89
• CPC Class Codes: H02M 7/05 Capacitor coupled rectifiers
• CPC Class Codes: H02M 7/066 particular circuits having a special characteristic

Abstract

A switching power supply includes a bridge rectifier, a switching device, and a controller. The bridge rectifier is operatively coupled to an alternating current (ac) signal, and outputs a rectified signal. The switching device is electrically connected in parallel with the bridge rectifier. The controller is responsive to the rectified signal and selectively controls the switching device to divert at least a portion of the rectified signal therethrough in response to the rectified signal. A method of supplying power includes coupling a bridge rectifier operatively to an alternating current (ac) signal, the bridge rectifier outputting a rectified signal, coupling a switching device electrically in parallel with the bridge rectifier, and controlling the switching device to divert at least a portion of the rectified signal therethrough in response to the rectified signal.

Claims

1. A power supply, which comprises:

a single capacitor directly coupled to an alternating current (ac) input signal without another capacitor coupled therebetween, the ac input signal comprising any ac input voltage selected from a range of ac input voltages spanning at least 300Vac;

a bridge rectifier, the bridge rectifier being operatively coupled through the capacitor to the ac input signal, the bridge rectifier outputting a rectified signal, the rectified signal providing power to a load;

a switching device, the switching device being electrically coupled in parallel with the bridge rectifier; and

a controller, the controller being responsive to the rectified signal, the controller selectively controlling the switching device to divert at least a portion of the rectified signal through the switching device and away from the load in response to the rectified signal, thereby providing at least one of a regulated voltage across the load and a regulated current through the load, the power supply being adapted to operate without an inductive component.

2. The power supply as defined by claim 1, further comprising an output and a first capacitor, the first capacitor being electrically coupled in parallel with the output.

3. The power supply as defined by claim 1, further comprising a second capacitor, the second capacitor being electrically coupled in series with the alternating current (ac) signal.

4. The power supply as defined by claim 1, further comprising a fuse, the fuse being electrically coupled in series with the alternating current (ac) signal.

5. The power supply as defined by claim 1, further comprising a resistor, the resistor being responsive to the alternating current (ac) signal, the resistor being electrically coupled in series with the bridge rectifier.

6. The power supply as defined by claim 1, further comprising a diode, the diode being electrically coupled in series with the bridge rectifier.

7. The power supply as defined by claim 1, wherein the controller selectively controls the switching device with a control signal, the control signal comprising a substantially constant frequency and a modulated pulse width.

8. The power supply as defined by claim 1, wherein the controller selectively controls the switching device with a control signal, the control signal comprising a modulated frequency and a substantially constant pulse width.

9. The power supply as defined by claim 1, wherein the switching device comprises at least one of a bipolar transistor, field effect transistor (FET), metal oxide semiconductor field effect transistor (MOSFET), discrete device, relay, and integrated circuit.

10. The power supply as defined by claim 1, further comprising an output, the controller selectively controlling the switching device in response to a voltage at an output of the power supply.

11. The power supply as defined by claim 1, further comprising an output the controller selectively controlling the switching device in response to a current at an output of the power supply.

12. The power supply as defined by claim 1, wherein the controller comprises at least one of a microprocessor, microcontroller, application specific integrated circuit (ASIC), programmable logic array (PLA), hybrid circuit, and discrete logic device.

13. The power supply as defined by claim 1, further comprising an output, the controller being electrically coupled in parallel with the output, the controller being adapted to selectively control the switching device such that a substantially constant voltage is maintained at the output.

14. The power supply as defined by claim 1, further comprising an output and a sensing resistor, the sensing resistor being electrically coupled in series with the output and outputting a sensing signal, the controller being responsive to the sensing signal, controller being adapted to selectively control the switching device such that that a substantially constant current is maintained at the output in response to the sensing signal.

15. The power supply as defined by claim 1, wherein the range of ac input voltages comprises 100Vac to 400Vac.

16. A method of supplying power comprising:

coupling a single capacitor directly to an alternating current (ac) input signal without another capacitor coupled therebetween, the ac input signal comprising any ac input voltage selected from a range of ac input voltages spanning at least 300Vac;

coupling a bridge rectifier operatively to the ac input signal through the capacitor, the bridge rectifier outputting a rectified signal, the rectified signal providing power to a load;

coupling a switching device electrically in parallel with the bridge rectifier; and

controlling the switching device to divert at least a portion of the rectified signal through the switching device and away from the load in response to the rectified signal, thereby providing at least one of a regulated voltage across the load and a regulated current through the load, the power supply being adapted to operate without an inductive component.

17. The method of supplying power as defined by claim 16, further comprising controlling the switching device with a control signal, the control signal comprising a substantially constant frequency and a modulated pulse width.

18. The method of supplying power as defined by claim 16, further comprising controlling the switching device with a control signal, the control signal comprising a modulated frequency and a substantially constant pulse width.

19. The method of supplying power as defined by claim 16, further comprising controlling the switching device in response to a voltage at an output of the power supply.

20. The method of supplying power as defined by claim 16, further comprising controlling the switching device in response to a current at an output of the power supply.

21. The method of supplying power as defined by claim 16, further comprising coupling a diode electrically in series with the bridge rectifier.

22. The method of supplying power as defined by claim 16, wherein the range of ac input voltages comprises 100Vac to 400Vac.