Abstract:
In an apparatus for controlling the power factor of a power distribution system connected to inductive loads, banks of delta connected capacitors are added to or removed from the power lines of the power distribution system by a plurality of solid state switching devices which are under the control of a microprocessor. The solid state switching devices include optically isolated SCR devices that do not generate electrical interference and provide transient free operation. The microprocessor is also capable of calculating the power factor and displaying it on a digital readout.
Abstract:
A stepping motor including a plurality of stator poles wherein the stator poles are non-symmetrically displaced from their normal position to reduce harmonics in the torquel displacement crossing of the motor.
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, is claimed. 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:
An improved process for making substrates for mounting and interconnecting high density components comprising a substrate core and at least two printed circuit conductor networks and wire scribed conductor filaments wherein connection between selected conductors of the printed circuit networks are formed by providing cavities reaching from a conductor in one network to a conductor in another network and depositing conductive material covering the cavity wall and reaching from one to the other conductor; encapsulating the surface with a resin composition and providing its surface with wire scribed conductors; encapsulating the thus formed surface and,at predetermined locations, providing cavities reaching from the encapsulant surface to the respective wire scribed conductor; and applying a conductive metal layer to said cavity and the core of said wire scribed conductor thus forming an electrical connection from said conductor core to said surface of said encapsulant layer.
Abstract:
In a process for scribing conductors in a predetermined pattern onto a surface of a substrate being adhesive coated, the adhesive coating being non-tacky and solid before activation and activatable by application of energy which may be applied by means of a pulsed radiation or heated fluid beam, and revert to the non-tacky, solid state after activation.
Abstract:
in a two-phase salient pole variable reluctance motor in which the number of stator poles (24-27) is four or a multiple of four, alternate stator poles carry windings (31-34) of different phases and each stator pole (24-27) has an elongated pole shoe (53), so that the pole tips (28, 29) of each adjacent pair of stator poles are at a relatively short circumferential spacing. Each rotor pole (35, 36) has an iron depletion layer (37) in the vicinity of its poleface surface (38) which defines a saturating zone, across which the greater part of the magnetomotive force produced by energisation of the stator windings is developed due to the uniform build-up of flux with rotor angle throughout almost the entire duration of pole overlap. A working stroke approximating to stator pole pitch is achieved. The circumferential extent of each rotor pole (35, 36) is matched to that of the stator poles (24-27) so that when the rotor poles are fully aligned with a pair of stator poles, each rotor poletip (41, 42) is located in the vicinity of a pair of spaced apart stator pole tips (28, 29), the relative disposition of the pole tips being such that when both phases of the motor are then simultaneously excited, fringing flux passes through the rotor poletips (41, 42), this flux being relatively strong for one poletip of each rotor pole and relatively weak for the other poletip. When the rotor poles are initially positioned so that there is partial overlap between rotor and stator poles, the motor is started by a conventional reluctance motor phase energisation sequence, but when the rotor poles are initially fully aligned with a pair of stator poles, in which position neither phase acting alone is capable of producing torque, both phases are excited simultaneously, so that torque is applied to the rotor by the flux asymmetry prevailing in these circumstances to move the rotor into a disposition from which a normal phase energisation may be followed. The motor is bi-directional and self-starting in both senses from any rotor posi- tinn
Abstract:
A method and apparatus for testing circuit boards using two or a small number of probes for making resistive and radio frequence 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 of 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 can also indicate approximate fault location.
Abstract:
A method and apparatus for automatically sensing and for 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. One type of sensor that can be used for this measurement is an on-press densitometer, or more generally, a reflectometer. If desired, the reflectance information obtained thereby can be converted to a registration error signal and used to achieve automatic, closed-loop control of the position of each of the color cylinders.
Abstract:
Die vorliegende Erfindung betrifft ein verbessertes Semi-oder Volladditiv-Verfahren zur Herstellung von Leiterplatten, bei welchem die zwischen den Leiterzügen freiliegende Haftvermittlerschicht praktisch ohne Angriff auf das Basismaterial oder das Kupfer der Leiterzüge in einer Behandlung mit einer alkalischen Permanganat-Lösung und nachfolgender geeigneter Spülschritte abgetragen wird.