Abstract: Catalytically imaged thermosetting and thermoplastic resin objects including printed circuit boards are provided. A hydrophilic, adhesion promoted insulating base material is treated in selected areas to produce metallic nuclei in the form of an image of a desired metal pattern. The image is exposed to an electroless metal bath to reinforce the image. Then, the non-imaged areas of the base are rendered hydrophobic by means of solvent treatment. The imaged areas are built up by metal deposition. Preferably, the solvent treatment of the non-imaged areas of the base material is repeated to enhance adhesion of the metal pattern to the base material.

Abstract: The spacing between two surfaces such as the space between a glass disk and a magnetic head or slider is measured by directing light from a broad spectrum light source onto the two surfaces, and combining the reflected light, with the light at different frequencies being combined constructively and destructively. The combined signals are analyzed at a large number of wavelengths to give a plot of intensity vs. wavelength, and the wavelength or wavelengths of maximum intensity (and constructive interference) and/or minimum intensity (destructive interference) are identified. For a glass disk and a metal slider with normal incidence, the light intensity minima occur at d=(1/2)nL and maxima at d=(1/2) (n-1/2) L, where d is the separation, L is the wavelength and n is a positive integer indicating the order. The actual plot of intensity vs. wavelength is correlated with the theoretical intensity vs.

Abstract: A compact actuator is disclosed in which the motor, gear reduction and motion control functions are performed by an integral array of components. Instead of having separate interconnected units to perform these functions, the integral array compacts these functions into a single unit, allowing a reduction in the overall length and total weight of an actuator capable of a given output stroke and force.

Abstract: An article comprised of metal directly and adherently bonded onto a ceramic substrate, and a process for producing same, wherein the ceramic is adhesion promoted with molten inorganic compound, treated with compounds that promote adsorption of catalyst for metal deposition, and plated with metal. Uniform surface coverage with catalyst and metal is ensured by the treatment with the adsorption promoters.

Abstract: A brushless tachometer in which output signal switching is achieved using field effect transistors and which is capable of achieving linearity over a broad range, particularly the zero speed region. According to a preferred embodiment, the brushless tachometer is operated in a current mode as part of the servo loop to substantially reduce tachometer voltage switching requirements. A ROM can be used to control commutation switching. Commutation is preferable line-to-neutral to reduce ripple.

Abstract: A method and apparatus for testing circuit boards using two or a small number of probes for making resistive and radio frequency impedance measurements e.g. capacitive measurements. The combination of resistive and impedance measurements substantially reduces the number of tests required to verify the integrity of a circuit board. The impedance or capacitive "norm" values used in testing the circuit boards can be obtained by operating the system in a learning mode. Analysis of the data provides not only fault detection but also can indicate approximate fault location.

Abstract: In a motor control system for a DC motor, a modulation circuit provides a plurality of pulse width modulated signals to control the current applied to the motor. The motor is coupled to a current sensing resistor and a plurality of switches responsive to the pulse width modulated control signals. The output of the current sensing resistor is summed with an input current command to provide an error signal. A modulation circuit which includes a waveform generator generates a plurality of interposed triangular waves adjustably offset by a predetermined amount. The triangular waves are compared to the error signal to provide pulse width modulated control signals which cause a "dither" current to be applied to the motor when there is substantially no input command and currents having substantially decreasing form factors to be applied as the input command increases.

Abstract: An alternator for use in a brushless DC tachometer which produces are output voltage with a trapezoidal waveshape. The alternator includes a three phase toroidal winding on a plotless core. The windings are concentrated rather than being distributed. The rotor includes high intensity permanent magnets configured to provide uniform flux density over a large segment at least equal to a commutation increment.

Abstract: An AC induction motor control system wherein two pulse trains are generated, one pulse train including a pulse for each increment of rotor movement, and the other pulse train having pulses occurring at a rate proportional to slip. The pulse trains are combined in a counter which controls formation of synthesized winding excitations developed from pre-recorded sine values. The slip pulse train is developed according to pre-recorded slip factors selected as a function of rotor speed and modified in accordance with desired torque.

Abstract: A resinous protective coating useful in adhering plastics to metallic substrates. The protective coating is particularly useful as a solder mask and in the manufacture of printed circuit boards with circuit patterns having a resolution of at least 0.25 mm lines and spaces thereon. The protective coating comprises resins dissolved in solvents, wherein the coating, upon being subjected to heat, goes from a liquid or soft "gel-like" state into a solid phase without bleeding. The protective coating is resistant to copper, nickel and gold electroplating baths, adheres to insulating substrates, adhesive coated base materials as well as metallic substrates and is capable of withstanding the thermal shock of dip soldering.

Abstract: A brush holder assembly providing longer brush life and easy brush replacement is disclosed. The assembly uses a removeable spring bracket to extend a double coil constant force extension spring straddling a brush. The bracket, straddling the spring and brush, is inserted into a brush holder, whereupon it slideably engages the coils of the extension spring, causing it to extend. The bracket is removeable from the holder so that the extension spring and brush can be removed to replace a worn or broken brush.

Abstract: A high speed DC brushless motor in which the stator is toroidal and the stator core does not include winding slots. In the preferred embodiment the core material for the stator is an amorphous metal alloy which provides high speed motor efficiency. For some applications core materials like ferrite or low silicon-alloys can be used. According to one embodiment of the invention a ferrite shielding ring can be added surrounding the motor to further improve high speed efficiency.

Abstract: A method and apparatus for automatically sensing and maintaining registration of each of the color cylinders utilized in a multi-color printing press is disclosed.Predetermined register marks are printed in the non-image areas on the sheet to be printed. Typically, in a four-color printing process, the black image is used as a reference, and registration of the other three image colors is achieved relative to the black image. Accordingly, a register mark for each process color is printed in the same location as a corresponding black reference register mark.The reference register marks are configured such that the average reflectance of the printed overlay will change as the registration of the color image changes with respect to the black image. In general, the configuration of the register marks for the black and color images differs.The reflectance of each printed overlay is measured on the printing press, while the sheet is moving.

Abstract: A process for making substrates for interconnecting components in which a filament is applied and affixed to a base in a pre-programmed pattern, the base surface and applied filaments are coated with a coating and the coating is hardened to form a substantially flat surface over the base and filaments. The coated base is then positioned on a table movable along "x" and "y" axes and the coated base is positioned under a high energy beam at pre-programmed points on the applied filament pattern and access openings are formed in the coating on the base at such points to expose the filament at each such point so that the exposed filament can be interfaced with the exposed surface of the coated base and articles for mounting and interconnecting components formed thereby.

Abstract: A variable frequency AC induction motor servo control system wherein slip is generated as a function of stator current. In a preferred embodiment the slip per ampere ratio is constant in the range from zero to approximately base speed and thereafter increases exponentially as the rotor speed increases above base speed.

Abstract: A process for making substrates for interconnecting components in which a filament is applied and affixed to a base in a pre-programmed pattern, the base surface and applied filaments are coated with a coating and the coating is hardened to form a substantially flat surface over the base and filaments. The coated base is then positioned on a table movable along "x" and "y" axes and the coated base is positioned under a high energy beam at pre-programmed points on the applied filament pattern and access openings are formed in the coating on the base at such points to expose the filament at each such point so that the exposed filament can be interfaced with the exposed surface of the coated base and articles for mounting and interconnecting components formed thereby.

Abstract: A brushless DC tachometer including an alternator which produces a substantially trapezoidal output signal coupled to an FET transistor switching bridge. The trapezoidal output signal is achieved using a block permanent magnet for one pole and a consequent pole contoured to achieve a substantially uniform flux density for the winding over a distance sufficient to produce a trapezoidal output signal.

Abstract: In a brushless DC motor of the type having a control circuit and a plurality of position sensors, an error detector responsive to the position sensors is used to generate an error signal useful in shutting off the motor. The output signals of the position sensors provide a numerical code representative of the rotation of the rotor relative to the windings. When the numerical code deviates from a predetermined sequence, the error detector generates an error signal and the control circuit shuts off the motor.

Abstract: The process and device in accordance with the present invention allow the simple and economic manufacture of printed circuit boards, wherein the metal of the conductors as well as the one covering the hole walls is identical with the metal being etched away from the areas between the conductors.According to this process, a one-or two-sided metal-coated base material is used which, upon production of the hole pattern, is provided in a known manner with a metal layer of desired thickness, covering the surface of the metal foil as well as the hole walls. Subsequently, a masking layer is applied by screen printing a positive image of the desired circuit pattern on the surface(s). In the following process step, the holes are filled with an ink by means of a screen printing stencil. In accordance with one embodiment of the invention, the ink used forms an etch-resistant surface film when drying. Upon etching, the masking layer as well as the surface film and the hole fillings are removed with a suitable solvent.

Abstract: New polymeric substrates for the electroless deposition of metal thereon. The substrates of the invention result from the polymerization of liquid mixtures comprising a liquid precursor of a polymer that is relatively susceptible to oxidative attack and a liquid precursor of a polymer that resists oxidation.