Universal AC adaptor
First Claim
1. Apparatus comprising:
- a safe input for receiving an isolated unipolar input voltage less than 50 volts and characterized by a periodic ripple having a characteristic frequency and a characteristic period;
a DC-DC switching power converter for converting power received from the safe input for delivery to a load via an output, the DC-DC switching power converter comprising one or more switches; and
a controller for operating the one or more switches in a series of converter operating cycles each having a duration that is 1% or less of the characteristic period,wherein the DC-DC switching power converter is adapted to deliver a controlled output to the load at an output voltage and to adjust an envelope of current drawn by the DC-DC switching power converter to perform power factor correction.
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Accused Products
Abstract
Power from an AC source at a source voltage is converted for delivery to a load at a DC load voltage, where the source voltage may vary between a high line voltage and a low line voltage in a normal operating range. DC-DC voltage transformation and isolation are provided in a first power conversion stage, the first stage having a CA input for receiving power from the source and a CA output for delivering a galvanically isolated unregulated AC adapter module (UAAM) voltage. First stage circuitry for performing the first power conversion stage is provided in a self-contained adapter module having input terminals for connection to the AC source and an output connected to the CA output for providing power to a second power conversion stage wherein the second power conversion stage is external to the adapter module.
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Citations
30 Claims
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1. Apparatus comprising:
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a safe input for receiving an isolated unipolar input voltage less than 50 volts and characterized by a periodic ripple having a characteristic frequency and a characteristic period; a DC-DC switching power converter for converting power received from the safe input for delivery to a load via an output, the DC-DC switching power converter comprising one or more switches; and a controller for operating the one or more switches in a series of converter operating cycles each having a duration that is 1% or less of the characteristic period, wherein the DC-DC switching power converter is adapted to deliver a controlled output to the load at an output voltage and to adjust an envelope of current drawn by the DC-DC switching power converter to perform power factor correction.
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2. The apparatus of claim 1 wherein:
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the periodic ripple comprises a series of pulses, the pulses being characterized by a pulse waveform, a pulse duration, and occurring at the characteristic frequency; and the power factor correction comprises adjusting an envelope of current drawn by the DC-DC switching power converter from the safe input to approximate the pulse waveform.
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3. The apparatus of claim 2 wherein the controlled output comprises voltage regulation.
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4. The apparatus of claim 2 wherein the controlled output comprises power regulation.
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5. The apparatus of claim 1 wherein the output is galvanically coupled to the safe input.
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6. The apparatus of claim 1 further comprising an isolation stage having a first input for receiving power from a source at a source voltage and a first output galvanically isolated from the first input connected to supply power to the safe input at a first output voltage, wherein the ratio of first output voltage to first input voltage is essentially fixed.
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7. The apparatus of claim 2 further comprising an isolation stage having a first input for receiving power from a source at a source voltage and a first output galvanically isolated from the first input connected to supply power to the safe input at a first output voltage, wherein the ratio of first output voltage to first input voltage is essentially fixed.
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8. The apparatus of claim 1 further comprising a first power conversion stage having an input for receiving power from a source and an output connected to supply unregulated power to the input, the input and output of the first power conversion stage being galvanically-isolated from each other.
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9. The apparatus of claim 6 wherein the isolation stage comprises a switching power conversion stage.
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10. The apparatus of claim 9 wherein the ratio comprises a first value for a first source voltage range and a second value for a second source voltage range.
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11. The apparatus of claim 7 wherein the first output voltage is unipolar and the power factor correction comprises adjusting an envelope of current drawn by the DC-DC switching power converter from the safe input to approximate a rectified sinusoid.
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12. The apparatus of claim 1 wherein the output voltage is lower than a peak of the voltage applied to the safe input.
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13. The apparatus of claim 1 wherein the DC-DC switching power converter comprises a buck-boost converter topology.
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14. The apparatus of claim 8 further comprising an enclosure for housing the isolation stage and the DC-DC switching power converter.
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15. The apparatus of claim 8 further comprising a first enclosure for housing the isolation stage and a second enclosure for housing the DC-DC switching power converter, wherein the first enclosure is separate and separated by a distance from the second enclosure.
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16. A method comprising:
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providing an isolated unipolar input voltage less than 50 volts and characterized by a periodic ripple having a characteristic frequency and a characteristic period to a safe input; converting, using a DC-DC switching power converter, power received from the safe input for delivery to a load via an output, the DC-DC switching power converter comprising one or more switches; and operating, using a controller, the one or more switches in a series of converter operating cycles each having a duration that is 1% or less of the characteristic period, wherein the DC-DC switching power converter is adapted to deliver a controlled output to the load at an output voltage and to adjust an envelope of current drawn by the DC-DC switching power converter to perform power factor correction.
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17. The method of claim 16 wherein:
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the periodic ripple comprises a series of pulses, the pulses being characterized by a pulse waveform, a pulse duration, and occurring at the characteristic frequency; and the power factor correction comprises adjusting an envelope of current drawn by the DC-DC switching power converter from the safe input to approximate the pulse waveform.
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18. The method of claim 17 wherein the controlled output comprises voltage regulation.
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19. The method of claim 17 wherein the controlled output comprises power regulation.
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20. The method of claim 16 wherein the output is galvanically coupled to the safe input.
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21. The method of claim 16 further comprising an isolation stage having a first input for receiving power from a source at a source voltage and a first output galvanically isolated from the first input connected to supply power to the safe input at a first output voltage, wherein the ratio of first output voltage to first input voltage is essentially fixed.
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22. The method of claim 17 further comprising an isolation stage having a first input for receiving power from a source at a source voltage and a first output galvanically isolated from the first input connected to supply power to the safe input at a first output voltage, wherein the ratio of first output voltage to first input voltage is essentially fixed.
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23. The method of claim 16 further comprising a first power conversion stage having an input for receiving power from a source and an output connected to supply unregulated power to the input, the input and output of the first power conversion stage being galvanically-isolated from each other.
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24. The method of claim 21 wherein the isolation stage comprises a switching power conversion stage.
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25. The method of claim 24 wherein the ratio comprises a first value for a first source voltage range and a second value for a second source voltage range.
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26. The method of claim 22 wherein the first output voltage is unipolar and the power factor correction comprises adjusting an envelope of current drawn by the DC-DC switching power converter from the safe input to approximate a rectified sinusoid.
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27. The method of claim 16 wherein the output voltage is lower than a peak of the voltage applied to the safe input.
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28. The method of claim 16 wherein the DC-DC switching power converter comprises a buck-boost converter topology.
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29. The method of claim 23 further comprising an enclosure for housing the isolation stage and the DC-DC switching power converter.
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30. The method of claim 23 further comprising a first enclosure for housing the isolation stage and a second enclosure for housing the DC-DC switching power converter, wherein the first enclosure is separate and separated by a distance from the second enclosure.
Specification