Abstract: A method and apparatus for sensing the proximity of a target object includes a sensor inductor (L.sub.S, 38) connected in series with an identical reference inductor (L.sub.R, 36) between an input and ground to form an inductive divider network. The sensor inductor is positioned so that its inductance can be varied in response to the proximity of a target object (14, 40) while the inductance of the reference inductor remains constant. Voltage pulses are periodically applied to the divider network from a source (32, 34) and divide across the reference and sensor in accordance with the ratio of the inductances, as varied or not by the presence of the target object. A detector (30) monitors the output of the divider network and provides a target status signal indicative of the proximity of the target object. For low-power operation, the detector circuit and conductive divider network are periodically and momentarily energized in synchronism.

Abstract: A magnetic field generator includes: a first coil group, including at least one coil, for generating a magnetic field upon energization; a second coil group, including at least one coil, and arranged such that a magnetic field is generated in substantially the same space as that of the magnetic field generated by the first coil group, a self-inductance of the second coil group being smaller than that of the first coil group; and a driving means for selectively energizing the first and second coil groups. The driving means energizes the second coil group first, and after the magnetic field is caused to rise by the second coil group, energizes the first coil group, thereby holding a constant magnetic field.

Abstract: A malfunction detector is connected to switches provided in a machine, such as a punch press, for actuation when a malfunction occurs. The detector is capable of supplying an alternating current test signal to the switches and determining whether the resistance of the switches to the test signal is greater than or less than a threshold value. The test signal preferably has a frequency which is equal to mains supply frequency or a harmonic thereof and the malfunction detector preferably only responds to changes of state of the switches during specific time windows.

Abstract: An electromagnetic driving circuit for driving a pendulum comprises a coil for detecting and driving a permanent magnet, a comparison circuit for comparing an induction voltage induced in the coil with a reference voltage, a generating circuit for generating driving pulses of a predetermined pulse width in response to outputs of the comparison circuit, and a driving circuit for flowing a driving current through the coil in accordance with the driving pulses. The timing at which the driving pulses are generated and/or the pulse width of the driving pulses are automatically adjusted to optimum values to improve the driving efficiency of the pendulum.

Abstract: A piezoelectric relay module having a plurality of relays of different load ratings is disclosed. Each relay is constructed from a portion of a single bimorph structure by cutting the bimorph structure to form bimorph actuators. The widths of the various bimorph actuators is varied to provide the different load ratings.

Abstract: A uniform magnetic field coil assembly having a plurality of pairs of coil elements each included in circuit comprising the parallel connection of a permanent current switch and its protecting means and an individual exciting power source, wherein the plurality of pairs of coil elements are symmetrically disposed against a plane perpendicular to the central axis of the uniform magnetic field coil assembly in the longitudinal direction and the plurality of pairs of coil elements are connected in series, thereby regulating the current flowing to each of the plurality of pairs of coil assembly elements for forming the uniform magnetic field coil as predetermined.

Abstract: A mechanically driven linkage causes a magnetic field acting on the object to be pulsed by alternately permitting and preventing a magnetic field from acting on the object during selected periods of time to relieve stress in the object or otherwise treat the object. Connections for applying a current through the object being treated are provided so that at the same the magnetic field is acting on the object a current added to affect the intermolecular structure of the object for various beneficial effects in treating. The current intensity and time cycle can be varied as desired and can be synchronized with the application of the magnetic field. Simple mechanical drives are used to selectively move the object or the magnetic field source, or to place a magnetic shield to block the field for selected periods of time, while permitting the magnetic field to act upon the object at other periods of time.

Abstract: In an electrical appliance having an electrically conducting housing, defective grounding of the housing may result in a dangerous situation for the user. To prevent such a dangerous situation, the appliance, also having an internal, load circuit, is provided with a safety connector device, which connector device comprises an electric plug having two power contacts through which the load circuit is energized, and two auxiliary contacts. The two latter, auxiliary contacts are respectively connected to two separate points of the housing so that they are interconnected together through an interconnecting circuit including the electrically conducting housing of the appliance. One of the two auxiliary contacts is connectable to a ground for grounding the housing whereby a disconnection of the ground from the housing can be detected by sensing a discontinuity in the interconnecting circuit.

Abstract: A device for conducting electrostatic potentials to a protection ground is disclosed. The device includes an electrically conductive center section mounted on a substrate mounting device, with the center section electrically connected to the protection ground. First and second electrically conductive bands extend from opposite sides of the center section. During the installation of a cirucit substrate to the substrate mounting device an associated band is arranged to contact a metalized edge of the circuit substrate providing an electrical path for discharging electrostatic potentials from the circuit substrate to the protection ground.

Abstract: A device for demagnetization of the picture tube of a television receiver and earthing of the conductive coating applied to the cone of the tube includes a demagnetization coil system (4) constituted by a bundle of insulated electric wires held together and forming at least one loop applied to the cone of the tube. The wires of the strand are held together by a tape of plastic material wound helically around them, while a bare electric wire (1) is wound helically with the same pitch as the tape. This wire is connected to earth (15, 16).

Abstract: A method for providing a power management for a DC solenoid actuator includes the steps of initially supplying a first number of DC current pulses to the actuator and after a first time interval reducing the number of pulses applied to the solenoid in direct proportion to an output voltage of a source of the DC power. The method further includes the step of changing the duration of the first time period in direct proportion to the output voltage of the source of the DC power.

Abstract: An electromagnetic relay provided with a light signaling device and comprising a support on which a base is fixed for a printed circuit carrying a LED and a resistor. A pair of conductors connect the printed circuit to a coil of attraction of the relay.

Abstract: Apparatus for ionizing air molecules to suppress electrostatic charges in a room or for other purposes includes internal feedback which maintains a desired rate of ion production in the presence of electrode deterioration or other effects which could otherwise alter ion output. Production of air ions of a given polarity results in a ground return flow of electrical charges of opposite polarity from the high voltage generator at a rate corresponding to the rate of air ion output. The ground return current is monitored to produce an electrical feedback signal. A control circuit causes the high voltage generator to apply higher voltage to the electrode when the feedback signal decreases and to apply lower voltage to the electrode when the feedback signal increases. Such self-regulation of each individual electrode in systems having an array of electrodes that are otherwise jointly controlled acts to maintain a desired ratio of positive and negative ions in a room as well as a desired total ion concentration.

Abstract: The combination of a heating element and a control unit therefor and methods of making and of operating the same are provided, the heating element normally being adapted to be operated by the continuous full-wave pulses of a certain high voltage alternating current source for a predetermined time period so as to provide a desired function thereof and the control unit being operatively interconnected to the heating element and having a first arrangement for operatively interconnecting the heating element to that certain high voltage alternating current source for the predetermined time period so as to provide a desired function thereof, the control unit having a second arrangement for operating the heating element with a certain repeating pattern of skipped complete half-wave pulses of another source of high voltage alternating current for the predetermined time period when that other source has a higher voltage than the certain source so that the heating element will not be adversely affected by the other sou

Abstract: A DC circuit breaker and a method of commutation during a commutation capacitor capable of being directly charged from a main DC line are disclosed. A breaker unit is inserted in a main DC line and is connected through a first switch in parallel to a series circuit including a commutation capacitor and a reactor. At end of the commutation capacitor is connected to the power side of the main DC line, and the other end thereof to the negative bus of the DC line through a charge capacitor. A series circuit including a magnetic repulsive coil and a second switch is connected in parallel to the commutation capacitor, which is directly charged from the power side of the main DC line. When the breaker unit starts to open, the second switch is turned on so that the polarity of the charged commutation capacitor is reversed to permit a discharged current to flow in the breaker unit in the opposite direction, while at the same time starting the opening of the breaker unit.

Abstract: Current injection electrostatic discharge equipment that includes a discharge capacitor connected to the input terminal of a switch or relay which selectively applies a current discharge from the capacitor to a test tip, the wave shape of the current discharge being shaped to match a standardized waveform. Shaping is achieved by providing first and second inductor coils in series between the output terminal of the switch and the test tip, and by providing an electrically conductive plate connected to the junction of the inductors so as to provide a free space capacitance.

Abstract: An electromagnetic relay includes a power supply element of the load circuit which is conducted around a part of the excitation flux circuit by at least one turn so that an auxiliary excitation flux is generated therein isodirectionally with the excitation flux of the winding. A reliable response of the relay is guaranteed even in relays wherein high currents are drawn by the load circuit from the same voltage source that delivers the excitation voltage, such as in relays in motor vehicles.

Abstract: A dielectric strength tester is disclosed for use with high-voltage, high-volt amperage electrical equipment. The step-up transformer has a high-voltage secondary winding which is connected through first and second primary windings of a sensing transformer to first and second test terminals. If an operator should contact the second test terminal, which is at high voltage, this would cause a fault-to-ground current, which is an imbalance on the two primary windings, and hence supply an output on the secondary winding of the sensing transformer. This voltage is rectified and passed through a set point resistor means to trigger a thyristor into conduction. This thyristor is connected to de-energize a triac in series with the primary of the step-up transformer. The sensing is rapid because it is carried out in the high voltage secondary, yet the control is in the lower voltage primary of the step-up transformer.

Abstract: A power supply for controlling a solenoid actuated lock includes high and low frequency pulse generators, the outputs of which control a switching transistor. The low frequency pulses seat the solenoid plunger, and the high frequency pulses maintain the plunger in the seated position.

Abstract: An electrical relay control circuit for a plurality of controlled devices such as electric motors in which the current for actuation of the relays is regulated so that only a predetermined and precise amount of current will be available for operation of the relay coils and that current will be sufficient for actuation of only one relay thereby restricting operation to one controlled device at any one time.