System and method to detect capacitance of a power supply unit
AssigneeQuanta Computer Inc.
InventorsKuang-Hua OU YANG, Chih-Chang TSAI, Shu-Chen NING
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Abstract
A power supply unit that allows measurement of the capacitance without interrupting operation of the unit is disclosed. The unit includes a controller that causes a voltage change of a capacitor from a first threshold voltage between two periods of time. The time difference of when the voltage reaches a second threshold voltage is measured and the capacitance is determined from the time measurement, voltage change and power dissipation. The determination of capacitance may be performed while the power supply unit is actively supplying power.
Claims18
A system to detect a capacitance of a capacitor in a power supply unit, the system comprising:
- a capacitor storing charge from a voltage source;
- a power correction circuit to set the voltage output from the capacitor at a first threshold voltage and change the voltage output from the capacitor to a second threshold voltage via the voltage source;
- and
- a controller operable to:
- determine a first time when the voltage output from the capacitor is at the first threshold voltage,
- determine a second time when the voltage output from the capacitor is at the second threshold voltage;
- determine power dissipation from the power supply unit between the first and second times;
- and
- determine the capacitance based on the first and second threshold voltages, the first and second times and the power dissipation.
A method of determining the capacitance of a power supply unit during operation of the power supply unit, the method comprising:
- setting an output voltage of a capacitor to a first threshold voltage at a first time;
- changing the output voltage of the capacitor to a second threshold voltage;
- determining when the capacitor outputs the second threshold voltage;
- determining a second time when the capacitor outputs the second threshold voltage;
- determining the power dissipated by the power supply unit between the first and second times;
- and
- determining the capacitance of the capacitor based on the first and second threshold voltages, the first and second times and the power dissipation.
A power supply unit operable to determine capacitance during operation, the power supply unit comprising:
- a power input;
- a power correction factor circuit coupled to the power input to output a voltage;
- a capacitor coupled to the power correction factor circuit, wherein the power correction circuit sets the voltage output from the capacitor at a first threshold voltage and changes the voltage output from the capacitor to a second threshold voltage;
- a DC to DC converter coupled to the capacitor, the DC to DC converter including a power output;
- and
- a controller operable to:
- determine a first time when the voltage output from the capacitor is at the first threshold voltage,
- determine a second time when the voltage output from the capacitor is at the second threshold voltage;
- determine power dissipation from the power supply unit between the first and second times;
- and
- determine the capacitance based on the first and second threshold voltages, the first and second times and the power dissipation.
Dependencies are inferred from the claim text.