Regulated open-loop constant-power power supply
First Claim
1. A constant-power switching power supply comprising an inductor having an inductor current that operates exclusively in discontinuous conduction mode (DCM), wherein the power supply is operative to supply and maintain constant output power to a load without measuring output parameters of the power supply, by regulating charge-up time of the inductor.
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Abstract
A constant-power switching power supply has an inductor with an inductor current that remains in discontinuous conduction mode (DCM), where the power supply supplies and maintains constant output power to a load without measuring output parameters, by regulating charge-up time of the inductor. A method of maintaining a constant output power for a power supply being run in discontinuous conduction mode (DCM), having an inductor, includes obtaining a measured input voltage for voltage being input to the power supply, obtaining from a memory a set of values based on the measured input voltage, and driving a pulse width modulation (PWM) generator based on the set of values, the driving of the PWM generator thereby regulating a charge-up time of the inductor to correspond to the measured input voltage, whereby the regulating of the charge-up time of the inductor maintains an essentially constant power for a load.
35 Citations
44 Claims
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1. A constant-power switching power supply comprising an inductor having an inductor current that operates exclusively in discontinuous conduction mode (DCM),
wherein the power supply is operative to supply and maintain constant output power to a load without measuring output parameters of the power supply, by regulating charge-up time of the inductor.
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15. An apparatus comprising:
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a voltage source that provides a voltage having polarity of plus and minus;
a constant-power power supply having a buck-boost topology and comprising;
a switch having a first terminal and a second terminal, the switch connected to the plus voltage at the first terminal;
an inductor having one end connected to the second terminal of the switch and having an other end;
a capacitor having one end connected to the one end of the inductor and having an other end;
a diode having a cathode connected to the other end of the capacitor and having an anode connected to the other end of the inductor and to the minus voltage; and
a control box operative to obtain a value based on a measurement of the voltage, and to operate the switch for regulating charge-up time of the inductor based on the value; and
a load connected across the capacitor;
wherein the inductor has an inductor current that remains in discontinuous conduction mode (DCM), and wherein the regulating of the charge-up time of the inductor provides an essentially constant power to the load. - View Dependent Claims (16)
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17. A power supply for supplying essentially constant power to one or more LEDs, comprising:
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an inductor;
means for measuring input voltage being applied to the power supply;
means for generating a pulse width modulation (PWM) signal based on the measured input voltage, the PWM signal having in a cycle of operation an ON portion, an OFF portion, and an IDLE portion;
means for storing energy in the inductor during the ON portion;
means for discharging energy from the inductor to the one or more LEDs during the OFF portion; and
a load that receives the energy discharged from the inductor as output power of the power supply;
wherein the means for storing energy in the inductor effects regulating of the output power without measuring output parameters of the power supply.
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18. A method of maintaining a constant output power for a power supply being run in discontinuous conduction mode (DCM), having an inductor, comprising:
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obtaining a measured input voltage for voltage being input to the power supply;
obtaining from a memory a set of values based on the measured input voltage; and
driving a pulse width modulation (PWM) generator based on the set of values, the driving of the PWM generator thereby regulating a charge-up time of the inductor to correspond to the measured input voltage, whereby the regulating of the charge-up time of the inductor maintains an essentially constant power for a load. - View Dependent Claims (19, 20, 21)
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22. A method of supplying constant power from a power supply to one or more LEDs, the power supply having an inductor, the method comprising:
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measuring input voltage being applied to the power supply;
generating a pulse width modulation (PWM) signal based on the measured input voltage, the PWM signal having in each cycle of operation an ON portion, an OFF portion, and an IDLE portion;
storing energy in the inductor during the ON portion; and
discharging energy from the inductor to the one or more LEDs during the OFF portion;
whereby the storing of energy in the inductor effects regulating of output power being supplied to the one or more LEDs without measuring output parameters of the power supply. - View Dependent Claims (23, 24, 25, 26)
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27. A method of regulating the output power of an inductor type switching power supply, the power supply having an input voltage, the method comprising:
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obtaining a value of the input voltage; and
regulating the ON time (charge-up time) of the inductor to correspond to the value of the input voltage so as to store a certain amount of energy in the inductor, whereby the regulating of the ON time of the inductor effects regulating of the output power without measuring output parameters of the power supply. - View Dependent Claims (28, 29, 30, 31, 32)
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33. A method of providing electric power to a semiconductor device, the method comprising:
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providing an open loop power supply configured in a buck-boost topology and having a shunt inductor;
measuring an input voltage of the power supply;
providing a translator that is operative to translate the measured input voltage into a set of values; and
adjusting a duty cycle of the electric power being provided to the semiconductor device based on the set of values.
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34. A method of controlling a constant power, switching power supply that operates in an open-loop configuration, the power supply having a switch that is turned on and off by pulse width modulation (PWM), the method comprising:
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graphing a value to obtain a first waveform;
adding a line to the first waveform representing the input voltage;
determining the time when the first waveform is above or below the line as being a PWM waveform; and
outputting the PWM waveform. - View Dependent Claims (35, 36)
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- 37. A method for calibrating a constant-power switching power supply having an inductor with an inductor current that operates exclusively in discontinuous conduction mode (DCM), the power supply being operative to supply and maintain constant output power to a load without measuring output parameters of the power supply, by regulating charge-up time of the inductor, the power supply having a voltage measurement unit that obtains a measured voltage being input to the power supply, the power supply having a PWM time base, the method comprising comparing a timing source having a known frequency to the PWM time base, thereby obtaining at least one time correction factor.
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44. A method for calibrating a flashlight having a buck-boost power supply that operates in discontinuous conduction mode (DCM) and that includes at least one light emitting diode (LED) as its source of illumination, the method comprising:
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positioning a brightness measurement unit to oppose the at least one LED;
varying an operating parameter of the power supply;
obtaining a brightness measurement of the at least one LED from the brightness measurement unit; and
repeating the varying and obtaining until a predetermined condition is met.
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Specification