Impedance Stabilization
AssigneeHewlett-Packard Development Company, L.P.
InventorSamuel M. Babb
Life of this patent
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Abstract
One embodiment of an impedance stabilizer for use with a switching voltage regulator supplied by a source of an electrical voltage has an impedance and a switch controllable to permit current from a source to flow through the impedance. Control circuitry to operate the switch cyclically with a controlled duty cycle is responsive to variations in the voltage of the source having a frequency lower than a cycle rate of the switch to increase the duty cycle of the switch as the voltage of the source increases.
Claims14
An impedance stabilizer for use with a switching voltage regulator supplied by a source of an electrical voltage, comprising:
- an impedance;
- a switch controllable to permit current from a DC power source to flow through the impedance, wherein the DC power source supplies a device having in operation negative apparent marginal impedance;
- and
- control circuitry to operate the switch cyclically with a controlled duty cycle, the control circuitry being responsive to variations in the voltage of the DC power source, the voltage of the DC power source having a frequency lower than a cycle rate of the switch to increase the duty cycle of the switch as the voltage of the DC power source increases so that a positive apparent marginal impedance is maintained in a circuit portion comprising an output of the DC power source and an input of the supplied device.
A power supply comprising:
- a source of DC power,
- a device supplied by the source of DC power and having in operation negative apparent marginal impedance, and
- an impedance stabilizer operative to maintain a positive apparent marginal impedance in a circuit portion comprising an output of the source of DC power and an input of the supplied device, the impedance stabilizer further comprising:
- an impedance;
- a switch controllable to permit current from the source of DC power to flow through the impedance;
- and
- control circuitry to operate the switch cyclically with a controlled duty cycle, the control circuitry being responsive to variations in the voltage of the source of DC power, the voltage having a frequency lower than a cycle rate of the switch to increase the duty cycle of the switch as the voltage of the source of DC power increases.
A method of stabilizing a power supply to a device having negative apparent marginal impedance, comprising:
- providing an impedance across the power supply to the device, wherein the device has in operation negative apparent marginal impedance;
- permitting current from the power supply to flow intermittently through the impedance by operating a switch cyclically with a controlled duty cycle, wherein the power supply has a DC power source;
- and
- in response to variations in a voltage of the power supply having a frequency low compared with a cycle rate of the switch, increasing the duty cycle of the switch as a voltage of the DC power source increases and decreasing the duty cycle of the switch as the voltage of the DC power source decreases so that a positive apparent marginal impedance is maintained in a circuit portion comprising an output of the DC power source and an input of the supplied device.
Dependencies are inferred from the claim text.