Abstract: A Class IV Partial Response Maximum Likelihood data channel for analog signal processing of a disk drive signal in tracking mode includes a signal error generating circuit for "folding" the analog disk drive signal around the three PR-IV target values of +1, -1 and 0. Using the smaller error signal rather than the larger analog disk drive signal by which the disk drive signal deviates from the target values results in significant power saving with no reduction in electronic signal to noise ratio. An integrated error generating circuit generates both a gain error signal and a timing error signal from the folded error signal for feedback control of the data channel variable gain amplifier and variable clock oscillator. Shared processing of the timing and gain error signals results in power savings and simpler circuitry.

Abstract: A Class IV Partial Response Maximum Likelihood data channel for analog signal processing of a disk drive signal in tracking mode includes a signal error generating circuit for "folding" the analog disk drive signal around the three PR-IV target values of +1, -1 and 0. Using the smaller error signal rather than the larger analog disk drive signal by which the disk drive signal deviates from the target values results in significant power saving with no reduction in electronic signal to noise ratio. An integrated error generating circuit generates both a gain error signal and a timing error signal from the folded error signal for feedback control of the data channel variable gain amplifier and variable clock oscillator. Shared processing of the timing and gain error signals results in power savings and simpler circuitry.

Abstract: A direct access storage device includes at least one disk mounted for rotation about an axis and having opposed disk surfaces for storing data. A magneto-resistive (MR) transducer head is mounted for movement across each respective disk surface for writing to and for reading data signals from the disk surface. Each MR transducer head includes a write element and a read element. A preamplifier, associated with the MR transducer head, amplifies read and write signals of the read element and the write element. A flex cable couples the read and write signals between the preamplifier and the MR transducer heads. The flex cable includes a common read return signal line for each sequential pair of the MR transducer heads.

Abstract: A high speed differential analog to digital converter (ADC) is provided. The high speed differential ADC includes a driver section, a comparator section and a decoder section. The driver section includes a pair of series connected resistor ladders with a positive phase voltage source connected at the top and bottom of one of the pair of series connected resistor ladders and a negative phase voltage source connected at the top and bottom of the other one of the pair of series connected resistor ladders; both the positive phase voltage source and the negative phase voltage source including a predetermined first DC voltage value. At least one additional positive phase voltage source is connected to the one of the pair of series connected resistor ladders and at least one additional negative phase voltage source is connected to the other one of the pair of series connected resistor ladders. The additional positive phase and negative phase voltage sources include a predetermined second DC voltage value.

Abstract: A high speed differential analog to digital converter (ADC) is provided. The high speed differential ADC includes a driver section, a comparator section and a decoder section. The driver section includes a pair of series connected resistor ladders. A positive phase and negative phase emitter follower transistor pair is connected to the pair of series connected resistor ladders. The positive phase and negative phase emitter follower transistor has a collector connected to a supply voltage and has an emitter coupled to a respective one of the pair of series connected resistor ladders. A respective positive phase and negative phase AC current source drives the base of the respective positive phase and negative phase emitter follower transistor. A reference DC current source is coupled to the base of the positive phase and negative phase emitter follower transistors for determining a range of the ADC. A current source transistor pair biases the emitter follower transistor pair.

Abstract: A lead-free percussion primer composition and a percussion cup containing e composition. The lead-free percussion primer composition is comprised of a mixture of about 45 wt % aluminum powder having an outer coating of aluminum oxide and molybdenum trioxide powder or a mixture of about 50 wt % aluminum powder having an outer coating of aluminum oxide and polytetrafluoroethylene powder. The aluminum powder, molybdenum trioxide powder and polytetrafluoroethylene powder has a particle size of 0.1 .mu.m or less, more preferably a particle size of from about 200-500 angstroms.

Abstract: A method for providing chemical energy and energetic compositions of matter consisting of thin layers of substances which will exothermically react with one another. The layers of reactive substances are separated by thin layers of a buffer material which prevents the reactions from taking place until the desired time. The reactions are triggered by an external agent, such as mechanical stress or an electric spark. The compositions are known as metastable interstitial composites (MICs). This class of compositions includes materials which have not previously been capable of use as energetic materials. The speed and products of the reactions can be varied to suit the application.

Abstract: A method for providing chemical energy and energetic compositions of matter consisting of thin layers of substances which will exothermically react with one another. The layers of reactive substances are separated by thin layers of a buffer material which prevents the reactions from taking place until the desired time. The reactions are triggered by an external agent, such as mechanical stress or an electric spark. The compositions are known as metastable interstitial composites (MICs). This class of compositions includes materials which have not previously been capable of use as energetic materials. The speed and products of the reactions can be varied to suit the application.

Abstract: An apparatus for the measurement of the critical current of a superconductive sample, e.g., a clad superconductive sample, the apparatus including a conductive coil, a means for maintaining the coil in proximity to a superconductive sample, an electrical connection means for passing a low amplitude alternating current through the coil, a cooling means for maintaining the superconductive sample at a preselected temperature, a means for passing a current through the superconductive sample, and, a means for monitoring reactance of the coil, is disclosed, together with a process of measuring the critical current of a superconductive material, e.g., a clad superconductive material, by placing a superconductive material into the vicinity of the conductive coil of such an apparatus, cooling the superconductive material to a preselected temperature, passing a low amplitude alternating current through the coil, the alternating current capable of generating a magnetic field sufficient to penetrate, e.g.

Abstract: A field emission electron gun (10) is disclosed which has an extraction electrode, composed of one or more sharply pointed electrode tips (17) in close proximity to a field emission cathode tip (11), such that a relatively low voltage between the cathode tip (11) and the extraction electrode tips (17), in the range of 100 to 2000 volts, will cause field emission of electrons from the cathode tip due to the extremely high localized electric field at the cathode tip. The electrons in the beam extracted from the cathode (11) are at a relatively low kinetic energy, particularly adapting the beam for use in such applications as low energy electron microscopy and low energy electron diffraction. For such applications, the extracted beam is generally passed through a limiting aperture member (21), electrostatic lenses (24, 25), and a deflection coil (26) when scanning of the target (27) is desired.