Abstract: A method and apparatus for operating a magnetic disk drive having a pole piece spaced apart from a magnetic disk surface by a predetermined distance to effectively form two plates of a parasitic capacitance capable of sustaining an undesirable electrical discharge capable of destroying data on the disk either by random discharge between the pole piece and magnetic disk or by discharge into imperfections on the disk. The invention comprises a circuit and method for applying a DC voltage to the pole piece and for simultaneously applying a DC voltage to the magnetic disk surface which is approximately equal to the DC voltage applied to the pole piece and thereby preventing the above parasitic capacitance between the pole piece and the magnetic disk surface from charging to a level sufficient to sustain any electrical discharge.

Abstract: In this system, the units are capable of transmitting and/or of receiving messages in at least a first format by way of a channel (A). Circuitry included in at least one of these units (B, M) are provided for transmitting on the channel (A), in a second format distinct from the first format, a message for putting the other electronic units (M) into operation.

Abstract: The present disclosure describes a method and a system for interconnecting a first and a second three-phase alternating electric networks.

Abstract: A switchgear apparatus comprising a switch mechanism, electrical controls for the switch mechanism, a weatherproof door movable between a closed position and an open position for respectively preventing and affording access to the electrical controls, a housing enclosing the switch mechanism and the electrical controls and including a second door for affording access to the weatherproof door, a third door movable between an open position and a closed position, an operating handle movable between an open position and a closed position, the operating handle being locatable in the open position only when the third door is in the open position, and a mechanism for releasably retaining the second door in the closed position, the mechanism being releasable only when the operating handle is in the open position.

Abstract: A lever (6) is pushed by a cam profile (23) formed on an actuating member (9) fastened to a movable body (12), the movement of which is to be detected. A cam (13) fixed to the lever moves a plunger (16) which actuates a position switch (33). There is interposed between the plunger and the switch an influencing member (22), the position of which is measured by means of a card (28) passing in front of photoelectric detectors (29). A processing unit (31) supplies, at the output, an analog or numerical signal relating to the position of the movable body (12), to its speed or to its acceleration.

Abstract: A power transition circuit protects a bipolar-CMOS (BiCMOS) circuit during power transitions. Reference signals proportional to the voltage supplied to the protected circuit are monitored, and the power transition circuit determines from the voltage differential between the reference signals whether a power transition is occurring. If a transition is present, the transition circuit disables the protected BiCMOS circuit for as long as the power transition exists. An independent input signal allows the power transition circuit to disable the protected BiCMOS circuit in response to other conditions.

Abstract: A motor controller or contactor is disclosed which utilizes a non-saturating current transformer for sensing the amount of current flowing in the electrical conductor connected to the contactor. The current sensor is made of homogeneous sintered powdered metal having evenly distributed microscopic air gaps therein which increase the reluctance of the magnetic circuit but resist the influence of stray magnetic flux. This increased reluctance prevents magnetic saturation over a wide range of input current and allows the secondary of the transducer to produce a voltage which is proportional to the derivative of the primary current, that is the current being sensed by the transducer. The aforementioned voltage is linearly proportional to the derivative of the current over a wide range of primary current values. This voltage is integrated to produce an output signal which is directly proportional to the aforementioned primary current over the wide range of current values.

Abstract: By providing two comparators, each of which have a reference voltage level source connected to one input, and separate voltage level producing/enhancing circuits connected to the contacts of a relay, so that each alternate switch configuration produces a different voltage level at the two comparators, a unique relay switch detection circuit is attained. Preferably, three separate voltage level producing/enhancing circuits are employed, with one circuit connected between the relay output and the two comparators, while the other two circuits are connected to the primary or the secondary relay contacts. Futhermore, the voltage level resulting from each particular switch configuration is pre-set relative to the reference voltage level source imputs to assure that the two comparators produce different combined outputs for each alternate switched condition.

Abstract: A current supply arrangement, for supplying at least one load with electric energy from a source, includes a switching stage for optionally switching-on the load according to a switching signal applied thereto and a control circuit which, in its switched-off state, cuts the supply of energy to the switching stage and, to the load and in its switched-on state, controls the energy supply to at least the switching stage. Current supply arrangements of such a type are used more specifically in television sets having remote control for "normal operation" and a "stand-by mode". So as to obtain for this arrangement the advantages of the "stand-by mode" and, on the other hand, to reduce the electrical power consumed and also the number of modules loaded by heating or voltage charges, the switching signal is also applied to the control circuit for switching between the switched-off and the switched-on states.

Abstract: A clamping device for holding cylindrical workpieces having a nominal radius R which varies from a minimum of (R-A) to a maximum of (R+B), where A and B are the limits of the tolerance range for the nominal radius, includes opposed clamp halves each having a clamp face adapted to be moved toward and away from one another and each of the clamp halves carrying a rigid collet element adapted to engage on opposite sides of cylindrical workpieces when the clamp halves are moved toward one another. Each of the collet elements has a semi-cylindrical clamping surface extending inwardly from the clamp face of the respective clamp half. Each semi-cylindrical clamping surface has a radius substantially equal to (R+B) with the center of the radius being offset outwardly of the clamp face of the respective clamp half an amount at least equal to (A+B). Preferably, the center of the radius is offset an amount at least equal to (A+B+C), where C is the tolerance deviation permitted to the radius (R+C).

Abstract: An electric connecting device which is arranged midway of a signal line which issues signals to a plurality of electrical appliances. This electric connecting device includes a combination of a plurality of connectors and a connector joining member having a plurality of connector joining parts which are joined electrically to each of the connectors. If at least one of the connectors is not joined normally, the joining of the remaining connectors is regulated by a regulating device which prevents the remaining connectors from being joined to the connector joining member. With the device it is possible to call the attention of an operator to any abnormal joining and to effect the joining of each connector accurately.

Abstract: Noise in the readback signal of a magnetic recording device resulting from spurious pulses in the readback signal produced by transitions of the magnetic remanent state of the yoke in the read/write transducer is eliminated by controlling the occurrence of the spurious pulses. Immediately following the completion of the write process, a decreasing amplitude alternating current is applied to the read/write coil of the transducer to drive the yoke remanent state to a stable or zero remanent state prior to the commencement of the read process.

Abstract: An apparatus for producing a solid aerosol, such as a carbon aerosol, in which aerosol particles are produced by spark discharge via particle-supplying electrodes and the particles are entrained by a gas flow. Electrodes having parallel, adjacent end faces and are prvided with a feed drive moving them synchronously in a direction toward one another.

Abstract: Apparatus for generating a magnetic field includes a superconducting coil winding and a conducting, non-magnetic electrical field member in proximity to and insulated from the winding. The winding is energized by a direct-current source, reaching a predetermined electrical potential when in the superconducting state. The electrical field member is held at a positive potential relative to the winding and the electrical field between the field member and the turns of the winding enables the winding to remain superconductive at current magnitudes exceeding the critical value that would have existed in the absence of such electrical field.

Abstract: This invention relates to a bus configuration for a dual channel variable speed constant frequency motor/generator aircraft power system providing for both power generation and engine starting. The subject invention provides for isolation of faults which can occur in long power feeders. Further, the subject invention provides for a novel start mode of operation which allows one channel to provide power to the other channel, thereby avoiding inefficient multiple converter operation and potentially faulty power buses. The bus configuration provides for coupling a first motor/generator to a second motor/generator via a first converter to thereby allow th first motor/generator, operating as a generator, to supply variable frequency power to the first converter, the first converter supplying variable frequency power to the second motor/generator to operate the second motor/generator as a motor.

Abstract: Electronic door lock system for use with a door mounted in a door frame and has a dead bolt and a latch mounted on the door. A control unit is mounted on the door in the vicinity of the dead bolt and the latch and includes a battery and electronic circuitry connected to the battery and manually operable contacts for selectively operating the dead bolt and the latch so that they can be moved to unlatched positions under the control of first and second hand-operated members.

Abstract: Permanent magnetic retaining device to move, affix or carry ferromagnetic parts or load with electronic switching of the magnetic flux to release the carried load includes a central iron core enclosed by a pair of magnet blocks secured by iron shoes, laterally joined to reinforcing plates and terminated by lateral poles with one or more compensator coils being disposed on the central core, with a sliding cover above the former, moving on a pair of guide pins surrounded by mechanical force gauges, the cover being centrally provided with a lifter eyelet. An electronic control circuit is incorporated externally in one of the side walls of a rectangular enveloping overcover wherein, at the opposite side thereof, a sensor of the electronic circuit is incorporated, to be operated manually and/or by remote control.

Abstract: A chair for conducting the electrostatic charge of an occupant to the floor on which the chair rests, with the chair seat carried on a support unit which permits rotation of the seat and adjustment of the height of the seat above the floor. The support unit includes an outer sleeve and an inner sleeve moving vertically relative to the outer sleeve, and an electrical resistor connected between the inner and outer sleeves and in sliding contact with at least one of the sleeves, typically by means of a spring finger strip mounted in a groove of a bushing or collar.

Abstract: An electrostatic-clamping robotic-type semiconductor wafer-holding blade designed to optimize the electrostatic clamping force and decrease the required clamping voltage. The wafer blade includes: a base; interleaved electrodes formed on the base, alternating electrodes being connected in common electrically; and preferably a layer of dielectric material such as Al.sub.2 O.sub.3 having a thickness ranging between 2 mils and 15 mils disposed over the interleaved electrodes and the base to minimize the applied voltage necessary to flatten the wafer against the blade, without dielectric breakdown. The ratio of electrode width to the distance between electrodes ranges from 3/1 to 2/1 to optimize the electrostatic clamping force exerted by the blade.

Abstract: An electrical connector for use in a vehicular smart power multiplexing network is disclosed. Smart power connectors provide for connections between the power network and the various peripheral devices and components in a vehicle. The connector is comprised of two body portions which are electrically coupled when closed. The first body portion includes three connectors for electrical connection to the power network and the peripheral devices and components. The second body portion includes the smart power circuit and heat sink for dissipating heat generated by the power stage components. The smart power connector also has diagnostic capabilities for detecting device and component load failures.