Abstract:
A method and system for detecting a charging current supplied to a portable device through a USB charger. The method includes the steps of connecting a charging circuit to a portable device, allowing the portable device to draw charging current from the charging circuit, measuring the current drawn from the charging circuit, comparing the measured current with a threshold value, making one or more system level decisions regarding charging of the portable device if the detected charging current is below the threshold current.
Abstract:
System and method for a USB host to determine whether or not a USB device provides power via a USB coupling between the USB host and the USB device. At a first time, it may be determined that the USB device is coupled to the USB host via a USB coupling and does not provide power. Power may be provided to the USB device via the USB coupling. At a second time it may be determined that the USB device does provide power via the USB coupling. Power may no longer be provided to the USB device via the USB coupling after it is determined that the USB device does provide power via the USB coupling. A battery of the USB host may be charged using power provided by the USB device via the USB coupling based on determining that the USB device does provide power via the USB coupling.
Abstract:
Adjusting current based on temperature. A change in temperature of a connection between a first device and a second device may be measured. The change in temperature may be performed while the first device provides current to the second device over the connection. If the change in temperature is above a threshold, the current being provided from the first device to the second device may be reduced. The change in temperature may be performed by the first device and/or the second device, e.g., by measuring the temperature of a connector of the connection.
Abstract:
An emulation system for charging any arbitrary portable device through a communication port on the portable device. The system includes a receptacle port for communicating with the portable device and a profile database for storing multiple charging profiles. Each charging profile including a set of parameters and at least one exit condition. Further, an emulation module applies a first charging profile to the portable device and monitors the set of parameters associated with the charging profile to identify an associated exit condition. Upon a determination that the exit condition for the first charging profile is met, the emulation module applies a next charging profile to the portable device.
Abstract:
A port power switch (PPS) may be used for lead compensation in systems where power is provided to a connected device by a switch-mode power supply (SMPS). The PPS may be designed to co-operate with the SMPS, providing a mechanism for the feedback reference point of the SMPS to be automatically switched, in the event of system fault or some other condition that might result in the PPS entering an “OFF’ operating mode, from the application point of load (POL) to the voltage input pin of the PPS without loss of power path continuity. The switching mechanism and the PPS may be manufactured to reside on the same integrated circuit. The PPS may include a control block that generates a control signal to couple the feedback port of the SMPS to the POL under normal operation, and to the voltage input port of the PPS during a fault condition.
Abstract:
A charging method and system for rationing charge or energy supplied by a host to a portable device. The system includes a power switch connected to a current sensing module that detects instantaneous current drawn by the portable device. A current register connected to the current sensing module stores the instantaneous current value. A timing module generates timing information. A cumulative charge value obtained by multiplying the instantaneous current value with the timing information is stored in a charge register. Further, a cumulative energy value may be obtained by multiplying the cumulative charge value with a detected voltage value. A threshold database stores a threshold value, and a rationing module connected to the host and the charge register continuously compares the cumulative charge value and/or the cumulative energy value with the threshold charge value. A control signal is generated when the threshold charge value is exceeded.
Abstract:
Adjusting current based on temperature. A change in temperature of a connection between a first device and a second device may be measured. The change in temperature may be performed while the first device provides current to the second device over the connection. If the change in temperature is above a threshold, the current being provided from the first device to the second device may be reduced. The change in temperature may be performed by the first device and/or the second device, e.g., by measuring the temperature of a connector of the connection.
Abstract:
A method and system for optimizing the behavior of a charger connected to a portable device when the portable device current exceeds the charger current limit. The system includes a configuration module configured to set a maximum current limit and a register-based current limit values. The system further includes a port power switch configured to limit the portable device current, in the event that the portable device current exceeds the maximum current limit value. The port power switch is configures to modify the portable device current to a predetermined constant current value or reset the current to zero based on the relation between the maximum current limit and the register-based current limit value.
Abstract:
A charging method and system for rationing charge or energy supplied by a host to a portable device. The system includes a power switch, and a current sensing module connected to the power switch. The current sensing module detects instantaneous current drawn by the portable device. The system further includes a current register connected to the current sensing module for storing the instantaneous current value. A timing module generates timing information. The system also includes a charge register storing a cumulative charge drawn by the portable device. The cumulative charge is obtained by multiplying the instantaneous current value with the timing information. A threshold database stores a threshold value, and a rationing module connected to the host and the charge register continuously compares the cumulative charge value with the threshold charge value. When the cumulative charge value exceeds the threshold charge value, a control signal is generated.
Abstract:
A three-dimensional and a two-dimensional GPS unit periodically provide coordinate positions of points on the work machine and are combined with a Kalman filter to produce a point of reference on a work machine. The point of reference is improved by combining the position with an inertial position derived from accelerometer data in another Kalman filter. Additionally, the two-dimensional GPS unit provides a heading that is combined with an inertial orientation derived by the angular rate from a gyroscope in another Kalman filter to produce a precise orientation estimate. Inclinometers provide pitch and roll of the work machine. With the point of reference, orientation estimate, pitch, roll and known geometry of the work machine, the GPS unit calculates the location and orientation of machine components and continuously tracks its movement throughout the mine. Additionally, the accelerometers and gyroscope provide position and orientation when the GPS units are inoperable.