Abstract: Systems and methods for electric vehicle battery systems with replaceable parallel electric vehicle battery modules are described herein. The electric vehicle battery system includes a plurality of electric vehicle battery modules connected in parallel. Each electric vehicle battery module includes a battery. Each electric vehicle battery module can also include a balancing circuit in electrical communication with a current path from the battery to an electric vehicle battery module output node. Each electric vehicle battery module also may have a current sensor in electromagnetic communication with the current path between the battery and the balancing circuit. The current sensor can be configured to sense a current level between the battery and the balancing circuit. The balancing circuit can be configured to balance the current level sensed by the current sensor of each electric vehicle battery module.

Abstract: Systems and methods for electric vehicle battery systems with replaceable parallel electric vehicle battery modules are described herein. The electric vehicle battery system includes a plurality of electric vehicle battery modules connected in parallel. Each electric vehicle battery module includes a battery. Each electric vehicle battery module can also include a balancing circuit in electrical communication with a current path from the battery to an electric vehicle battery module output node. Each electric vehicle battery module also may have a current sensor in electromagnetic communication with the current path between the battery and the balancing circuit. The current sensor can be configured to sense a current level between the battery and the balancing circuit. The balancing circuit can be configured to balance the current level sensed by the current sensor of each electric vehicle battery module.

Abstract: Systems and methods for electric vehicle battery systems with replaceable parallel electric vehicle battery modules are described herein. The electric vehicle battery system includes a plurality of electric vehicle battery modules connected in parallel. Each electric vehicle battery module includes a battery. Each electric vehicle battery module can also include a balancing circuit in electrical communication with a current path from the battery to an electric vehicle battery module output node. Each electric vehicle battery module also may have a current sensor in electromagnetic communication with the current path between the battery and the balancing circuit. The current sensor can be configured to sense a current level between the battery and the balancing circuit. The balancing circuit can be configured to balance the current level sensed by the current sensor of each electric vehicle battery module.

Abstract: Systems and methods for electric vehicle battery systems with replaceable parallel electric vehicle battery modules are described herein. The electric vehicle battery system includes a plurality of electric vehicle battery modules connected in parallel. Each electric vehicle battery module includes a battery. Each electric vehicle battery module can also include a balancing circuit in electrical communication with a current path from the battery to an electric vehicle battery module output node. Each electric vehicle battery module also may have a current sensor in electromagnetic communication with the current path between the battery and the balancing circuit. The current sensor can be configured to sense a current level between the battery and the balancing circuit. The balancing circuit can be configured to balance the current level sensed by the current sensor of each electric vehicle battery module.

Abstract: The software system architecture supports a rotating media in the storage and retrieval of data, where the rotating media stores in data tracks of multiple sectors, through the use of a microcontroller for the execution of a control program that schedules plural control tasks temporally distributed for respective execution during the rotational period of a predetermined track and sector. The scheduling of the plural control tasks is synchronized with respect to data retrieved from the predetermined sector. The plural control tasks include a rotational control task for determining an adjustment to the spin speed of the rotating media, a track following task for determining an adjustment to the alignment of the read/write head with respect to the predetermined track and a sector timing task for determining the position of the read/write head with respect to the predetermined track.

Abstract: A contact start/stop architecture for disk drives overcomes problems introduced by low flying MR (magnets resistive) heads and textured landing zones. Takeoff velocity for heads vary from the textured landing zone to the data zone. Contact start/stop operations are controlled relative to a critical takeoff velocity between takeoff velocity in the data zone and takeoff velocity in the landing zone, which critical velocity is less than that required to achieve negligible contact between the head and disk surface while the head is within the landing zone, but greater than takeoff velocity within the data zone. An initial seek from the landing zone begins at critical takeoff velocity. The head drags along the disk surface in the landing zone, since it has not reached takeoff velocity within the landing zone, but will immediately be at fly height as soon as the head reaches the data zone, minimizing the total drag distance of the head in the landing zone.

Abstract: An apparatus and method for controlling the frequency at which data is written in a disk drive system is disclosed. Data is written into a record stored in a disk drive system at a frequency which is controlled by a clock signal that accounts for the frequency of format data in the record to be written and the rotational speed of a disk in the disk drive system. The clock is generated by a phase locked loop which receives format data read from the record to be written and a compensation factor received by monitoring rotational speed of the disk, resulting in data being written with a frequency and phase equal to the frequency and phase that the format data read from the record to be written would have had if the disk were rotating at its nominal speed.

Abstract: An apparatus that compensates for the asymmetry and the baseline shift in the signal generated by a magnetoresistive head. The apparatus stores a first correction factor for the baseline shift, a second correction factor for correcting the amplitude of the positive portion of the signal and a third correction factor for correcting the amplitude of the negative portion of the signal. The first correction factor for correcting for baseline shift is added to the signal generated by the magnetoresistive head to generate a baseline corrected signal. The baseline corrected signal is then monitored for positive and negative excursions from the baseline and the positive excursions are multiplied by the second correction factor and the negative excursions are multiplied by the third correction factor for generating a compensated signal.

Abstract: A contact start/stop architecture for disk drives overcomes problems introduced by low flying MR heads and textured landing zones. Takeoff velocity for heads vary from the textured landing zone to the data zone. Contact start/stop operations are controlled relative to a critical takeoff velocity between takeoff velocity in the data zone and takeoff velocity in the landing zone, which critical velocity is less than that required to achieve negligible contact between the head and disk surface while the head is within the landing zone, but greater than takeoff velocity within the data zone. An initial seek from the landing zone begins at critical takeoff velocity. The head drags along the disk surface in the landing zone, since it has not reached takeoff velocity within the landing zone, but will immediately be at fly height as soon as the head reaches the data zone, minimizing the total drag distance of the head in the landing zone.

Abstract: A head-disk assembly contains an actuator that includes magnetoresistive heads and a preamplifier. The preamplifier is grounded to the actuator, and the actuator is grounded to a baseplate head-disk assembly via a ground conductor. A first inductive loop, which results in noise coupling on the pre-amplifier, exists based on the unequal potential between the actuator and the baseplate. The length of the ground conductor is minimized to reduce the area of the first inductive loop. A second inductive loop arises from a conductive path from the pre-amplifier leads to the baseplate via the actuator suspension, slider body assembly, magnetoresistive head, and magnetic disk media. A reduction of the unequal potential, which results in the second inductive loop, reduces noise coupling onto the inputs of the pre-amplifier. Conditioning of power, signal and control traces are also disclosed.

Abstract: A hard disk drive system operates from a limited power source to provide for the storage of data on the surface of a rotating hard disk media. An embedded controller incorporates a data channel for transferring data with respect to a hard disk media. The controller includes first and second subsections and a power-down circuit for providing separately switchable power from the power source to the first and section subsections. The controller further includes a processor for controlling the power-down circuit. The processor nominally provides a low duty cycle control signal to the power-down circuit for switching the provision of power to the first subsection of the controller.

Abstract: A disc drive device where data and servo position information is stored in data segments on concentric tracks on the disc surface. The servo position information indicates the track centerline for each data segment. The offset of the servo position information from an ideal track centerline for each track is measured and stored into memory. The read/write head, which accesses data on the disc tracks, is positioned over the track centerline based on the offset for each data segment.

Abstract: This invention provides for increasing useful data area on a zone-textured disc. The disc drive device has at least one disc having a CSS zone and a data zone with a plurality of concentric tracks on the disc surface. The contact start/stop zone of the disc surface is where the slider takes off from and lands on the disc surface. Each track includes at least one data segment capable of storing data. A transducer writes data to and reads data from the concentric tracks on the surface of the disc. The transducer is connected to a slider which has an air bearing surface (ABS) with an inner side and an outer side. In the present invention, the fly height of the inner side of the ABS is greater than a fly height of the outer side of the ABS in the area of the data zone nearest to the CSS zone.

Abstract: A circuit is described to detect and qualify a dibit signal, wherein the dibit signal includes a first peak amplitude followed by a second peak amplitude. The circuit includes a first qualification circuit that receives the signal and operates to detect and qualify the first peak amplitude of the dibit signal. The first qualification circuit also operates to assert an enable signal upon qualification of the first peak amplitude. A second qualification circuit is coupled to the first qualification circuit to receive the enable signal. The second qualification circuit operates to output an output signal representative of the dibit signal upon a second peak amplitude of the dibit signal only when the enable signal is asserted by the first qualification circuit.

Abstract: A read channel is described for use in a storage device including a storage medium for storing data, an interactive element for reading information from and writing information on the storage medium and a processor for performing control functions in the storage device. The read channel comprises a set of electronic components for receiving and processing information read by the interactive element from the storage medium. An adjustable noise generator is included in the read channel and is coupled to the set of electronic components. The noise generator is selectively operated to introduce noise into the set of electronic components to cause the set of electronic components to operate at a marginal level of performance and thereby increase the error rate of the read channel. A calibration of the read channel is performed when the read channel is operating at the marginal level of performance to decrease the time required to accumulate error statistics used in the calibration.

Abstract: A hard disk drive implemented as a plug-in module has a height of 10 mm and a foot print of 85.6 mm.times.54 mm. The footprint corresponds to the dimensions of memory cards. The disk drive uses a modified suspension in which the load beams are welded to actuator plates, thereby eliminating the use of a stakable suspension. The disk may be a glass substrate having a thickness of approximately 0.381 mm (0.015") or an aluminum substrate having a thickness of approximately 0.635 mm (0.025").

Abstract: A microcontroller managed adaptive control system, including a precompensator and a passive equalizer, is provided to decrease the read error rate of a disk drive. An adaptively controllable programmable precompensator adjusts the timing of data bits being written to a disk recording surface with the timing adjustment being relative to the individual bit timing windows. A novel adaptively controllable programmable equalization circuit is provided to enhance the peak amplitudes of data bits read at high frequencies. A microcontroller is programmed to control the programmable precompensator and equalizer to determine the threshold for and subsequently enable the precompensation of the write data and, independently, the equalization of read data with respect to a given media surface.

Abstract: A hard disk drive system operates from a limited power source to provide for the storage of data on the surface of a rotating hard disk media. An embedded controller incorporates a data channel for transferring data with respect to a hard disk media. The controller includes first and second subsections and a power-down circuit for providing separately switchable power from the power source to the first and section subsections. The controller further includes a processor for controlling the power-down circuit. The processor nominally provides a low duty cycle control signal to the power-down circuit for switching the provision of power to the first subsection of the controller.

Abstract: A digital phase detector that stores four sequential digital samples in a shift register. The contents of the shift register is evaluated at one half the clock frequency which generated the digital samples. The digital phase detectors predicts what the value should be for each of the two middle samples in the shift register. The predicted value and the actual value of each middle are used to generated a correction signal. The correction signals for the two middle samples are then added to produce a total correction signal which is to be used in controlling the phase and frequency of the voltage controlled oscillator in the phase locked loop generating the clock that controls the generation of the digital samples.

Abstract: A hard disk drive system operates from a limited power source to provide for the storage of data on the surface of a rotating hard disk media. An embedded controller incorporates a data channel for transferring data with respect to a hard disk media. The controller includes first and second subsections and a power-down circuit for providing separately switchable power from the power source to the first and section subsections. The controller further includes a processor for controlling the power-down circuit. The processor nominally provides a low duty cycle control signal to the power-down circuit for switching the provision of power to the first subsection of the controller.