Abstract: A wireless power transfer system may wirelessly transmit and receive power. A transmitting coil may wirelessly transmit the power. A receiving coil may be magnetically but wirelessly coupled to the transmitting coil and may wirelessly receive the power and generate an AC input voltage. A rectifier may rectify the AC input voltage. A capacitance may filter the rectified AC input voltage. An electronic switch may be connected in series between the rectified AC input voltage and an output. A load may be connected to the output. A controller may open and close the electronic switch so as to cause the output to be at a constant DC voltage, notwithstanding variations in the load.

Abstract: A wireless power transfer system may wirelessly transmit and receive power. A transmitting coil may wirelessly transmit the power. A receiving coil may be magnetically but wirelessly coupled to the transmitting coil and may wirelessly receive the power and generate an AC input voltage. A rectifier may rectify the AC input voltage. A capacitance may filter the rectified AC input voltage. An electronic switch may be connected in series between the rectified AC input voltage and an output. A load may be connected to the output. A controller may open and close the electronic switch so as to cause the output to be at a constant DC voltage, notwithstanding variations in the load.

Abstract: A battery balancing system includes at least one sub-stack, each sub-stack comprising a plurality of cells connected in series. The system also includes a balancing module for each sub-stack comprising an independent bidirectional balancer for each cell in the sub-stack. The system includes a daisy chained stackable serial port. The balancing system senses a state of charge (SOC) of each cell in each sub-stack. The average SOC of the sub-stack is determined. For a weak cell, additional charge is provided from its respective sub-stack during the discharging of the battery. For a strong cell, additional charge is removed and provided to its respective sub-stack during discharging of the battery. Any number of sub-stacks can be stacked in series while maintaining the same serial control, allowing a theoretically unlimited number of cells to be supported from a single communication port without the need for additional digital isolators.

Abstract: A battery balancing system includes at least one sub-stack, each sub-stack comprising a plurality of cells connected in series. The system also includes a balancing module for each sub-stack comprising an independent bidirectional balancer for each cell in the sub-stack. The system includes a daisy chained stackable serial port. The balancing system senses a state of charge (SOC) of each cell in each sub-stack. The average SOC of the sub-stack is determined. For a weak cell, additional charge is provided from its respective sub-stack during the discharging of the battery. For a strong cell, additional charge is removed and provided to its respective sub-stack during discharging of the battery. Any number of sub-stacks can be stacked in series while maintaining the same serial control, allowing a theoretically unlimited number of cells to be supported from a single communication port without the need for additional digital isolators.

Abstract: A circuit for driving a brushless dc motor includes an active deceleration circuit for rapidly slowing the motor. A phase locked loop senses a position of the rotor for commutating from a drive state to a next drive state in a sequence of drive states at an appropriate time for maintaining torque on the rotor in the direction of rotation. Thus, the rotor "chases" the energized windings. A speed control loop controls current in the windings and, thus, motor speed. When the speed of the motor exceeds a desired speed by more than a threshold amount, rather than commutating to a next drive state in the sequence, the circuit skips a commutation. By skipping one commutation, the current drive state is maintained while the rotor continues to turn, due to its own inertia, such that the rotor "passes up" the current drive state. This results in a torque on the rotor in a direction opposite rotation.

Abstract: A signal generator generates a reference signal, centered about a reference voltage and having a predetermined period. The signal generator also generates output signals P and Z. The output signal P is a squarewave which changes levels at the peaks of the reference signal. The output signal Z is a squarewave which changes levels at the reference voltage crossings of the reference signal. A phase-shifted signal generator generates a phase-shifted signal using the output signals P and Z by switching in appropriate signal levels from the signal generator. The output signals P and Z are input to a switch control circuit which controls a network of switches, depending on a current region of the reference signal, to couple appropriate signals to an amplifier circuit. The switch control circuit determines the current region based on the state of the output signals P and Z. The amplifier circuit provides the phase-shifted signal in response to the signals coupled to it by the network of switches.

Abstract: The invention is an active, hot insertable, SCSI terminator circuit having a bypass device that permits an initially unpowered active SCSI terminator to be coupled to a signal line of a powered SCSI bus such that no damage results to the SCSI terminator circuit itself or to other SCSI devices on the SCSI bus, and without having the effect of altering the existing state of the SCSI bus as a result of the coupling. Preferably, the terminating element of the SCSI terminator is a p-channel MOSFET. The SCSI terminator is prevented from being damaged during the coupling by using the bypass device to effectively short the gate of the p-channel MOSFET terminating element to its drain. When the drain of the p-channel MOSFET terminating element is shorted to its gate the amount of current the SCSI terminator may draw from any and all SCSI signal lines during the coupling is substantially limited to less than 50 .mu.A.

Abstract: The invention employs an active element, a p-channel MOSFET, between a regulated voltage and a SCSI terminating line. An "ideal" current source terminator is most effective when a signal line is negated (low-to-high transition), whereas a resistive terminator is most effective when a signal line is asserted (high-to-low transition). The I-V characteristics of a p-channel MOSFET, wherein the relationship between the termination voltage and the termination current is characterized by a nonlinear and smooth voltage versus current curve, provide an optimized transient response for signal negations and signal assertions on a SCSI bus.

Abstract: A scale utilizes a plurality of load cells positioned beneath a weighing platform for determining the weight of objects placed upon the platform. During a weighing operation, each load cell generates a voltage proportional to the response of said cell to the application of a weight to the platform. Each such generated voltage is transmitted serially through a multiplexer and is converted to a digital value by an analog-to-analog converter. These digital values are employed by a microprocessor to determine the weight of the object placed on the weighing platform. The scale is calibrated by weighing a test weight in a plurality of different locations on the weighing platform, and utilizing the individual digital values thus obtained for each load cell in a plurality of simultaneous equations, which are then solved in the microprocessor to provide constant values associated with each load cell, which are used in subsequent weighing operations.