Methods of and apparatus for controlling power drawn by an appliance through a USB port
First Claim
1. Apparatus for controlling power drawn by an appliance from a power source through a USB port having D+ and D−
- data lines, a power line, and a ground line, the apparatus comprising;
a pull-down resistor switchingly connectable to the D+ data line;
a current source switchingly connectable to the D+ data line;
a voltage source switchingly connectable to the D+ data line;
a voltage sensor in communication with the data lines; and
a controller programmed to selectively connect the pull-down resistor, the current source, and the voltage source to the D+ data line and to limit any electrical current drawn from the power source to any of a first level through a seventh level according to voltage levels on the D+ and D−
data lines.
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Accused Products
Abstract
Methods of and apparatus for controlling power drawn by an appliance through a USB port. The method includes limiting any electrical current drawn by an appliance to one of seven levels according to whether the data lines receive a bias from a power line, the data lines are in electrical communication with each other, and the power source includes a host computing device, or according to logic and voltage levels of the data lines when any of the pull-down resistor and the current and voltage sources are connected or not connected to the D+ data line. The apparatus includes a controller programmed to selectively connect a pull-down resistor, a current source, and a voltage source to a D+ data line and to limit any electrical current drawn from a power source to one of the seven levels according to voltage levels on the D+ data line and a D− data line.
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Citations
15 Claims
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1. Apparatus for controlling power drawn by an appliance from a power source through a USB port having D+ and D−
- data lines, a power line, and a ground line, the apparatus comprising;
a pull-down resistor switchingly connectable to the D+ data line; a current source switchingly connectable to the D+ data line; a voltage source switchingly connectable to the D+ data line; a voltage sensor in communication with the data lines; and a controller programmed to selectively connect the pull-down resistor, the current source, and the voltage source to the D+ data line and to limit any electrical current drawn from the power source to any of a first level through a seventh level according to voltage levels on the D+ and D−
data lines. - View Dependent Claims (2, 3, 4, 5, 6)
- data lines, a power line, and a ground line, the apparatus comprising;
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7. A method of controlling power drawn by an appliance through a USB port, the method comprising:
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connecting a power source to an appliance through a USB port having D+ and D−
data lines, a power line, and a ground line;testing the D+ data line to determine whether it receives a bias from the power line; if the D+ data line receives a bias from the power line, testing the D−
data line to determine whether it receives a bias from the power line, and if the D−
data line does not receive a bias from the power line, limiting any electrical current drawn from the power source to a first level and exiting, and if the D−
data line receives a bias from the power line, testing the data lines to determine whether they are in electrical communication with each other in the power source, and if the data lines are in communication with each other, limiting any electrical current drawn from the power source to a second level and exiting, and if the data lines are not in communication with each other, limiting any electrical current drawn from the power source to a third level and exiting;if the D+ data line does not receive a bias from the power line, testing the D−
data line to determine whether it receives a bias from the power line;if the D−
data line receives a bias from the power line, limiting any electrical current drawn from the power source to the first level and exiting;if the D−
data line does not receive a bias from the power line, testing the D+ data line to determine whether the power source comprises a host computing device;if the power source does not comprise a host computing device, testing the D−
data line to determine whether the power source can provide an electrical current at a fourth level, and if so, limiting any electrical current drawn from the power source to the fourth level and exiting, else limiting any electrical current drawn from the power source to the first level and exiting;if the power source comprises a host computing device, testing the D−
data line to determine whether the host computing device can provide an electrical current at a fifth level, and if so, limiting any electrical current drawn from the host computing device to the fifth level and exiting, else performing a USB emulation to determine whether the host computing device can provide current at a sixth level, and if so, limiting any electrical current drawn from the host computing device to the sixth level and exiting, else limiting any electrical current drawn from the host computing device to a seventh level and exiting. - View Dependent Claims (8, 9, 10, 11)
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12. A method of controlling power drawn by an appliance through a USB port, the method comprising:
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connecting a power source to an appliance through a USB port having D+ and D−
data lines;disconnecting any pull-up and pull-down resistors from the data lines in the appliance; if the D+ data line is not at logic HI and the D−
data line is not at logic LO, limiting any electrical current drawn from the power source to a first level and exiting;if the D+ data line is at logic HI and the D−
data line is not at logic HI, limiting any electrical current drawn from the power source to the first level and exiting;if both data lines are at logic HI, connecting a pull-down resistor to the D+ data line, and if the D−
data line is at logic LO, limiting any electrical current drawn from the power source to a second level and exiting, else limiting any electrical current drawn from the power source to a third level and exiting;if the D+ data line is not at logic HI and the D−
data line is at logic LO, connecting a current source to the D+ data line;if both data lines are at logic HI with the current source connected, disconnecting the current source, limiting any electrical current drawn from the power source to a fourth level, and exiting; if the D+ data line is at logic HI and the D−
data line is not at logic HI with the current source connected, disconnecting the current source, limiting any electrical current drawn from the power source to the first level, and exiting;if the D+ data line is not at logic HI with the current source connected, applying a voltage source to the D+ data line and determining whether a voltage level of the D−
data line is within a predetermined voltage range;if the voltage level of the D−
data line is within the predetermined voltage range, disconnecting the current and voltage sources, limiting any electrical current drawn from the power source to a fifth level and exiting;if the voltage level of the D−
data line is not within the predetermined voltage range, disconnecting the current and voltage sources and performing a USB enumeration to determine whether the power source is capable of providing a sixth level of electrical current, and if so, limiting any electrical current drawn from the power source to the sixth level and exiting, else limiting any electrical current drawn from the power source to a seventh level and exiting. - View Dependent Claims (13, 14, 15)
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Specification