Abstract: An arrester for use under oil in an electrical apparatus, the arrester comprising a first contact assembly, a plurality of valve blocks, a second contact assembly, and a conductive cement serially electrically connecting the first contact assembly, each of the plurality of valve blocks, and the second contact assembly. The arrester also includes a thin insulative inert to oil coating completely covering the plurality of valve blocks, the coating and the cement permitting electrical separation of the valve blocks in the event of electrical destruction of the valve blocks.

Abstract: A multi stage heater heats items on a conveyor so that they follow a predetermined temperature profile. The heater is used for printed circuit boards or the like when heated for soldering and avoids thermal gradients that can occur with heating different materials. The heater has a first heater for applying a first quantity of heat to items on the conveyor, a temperature sensing device for determining temperature of items leaving the first heater, a second heater downstream of the first heater and a control system which compares signals from the temperature sensing device with a predetermined temperataure profile to produce a first control output to control the first heater and a second control output to control the second heater so that items passing through the heater follow the predetermined temperature profile.

Abstract: A pressure contact semiconductor device has a semiconductor substrate disposed on a metal post electrode through metal electrode plate, an insulating ring engaged with the periphery of the metal post electrode extends to the periphery of the metal electrode plate and is brought into contact therewith at a certain height with a sufficient contact pressure. The semiconductor substrate is positioned precisely with respect to the metal post electrode so that a gate electrode ring is precisely positioned on a gate electrode film formed on the upper surface of the semiconductor substrate.

Abstract: A thermal printer with a fault detection circuit for detecting faults in heating elements of the printer includes a print head containing heating elements and a heating circuit for each heating element and a power supply for supplying power to the heating elements. Power is supplied to the print head either directly through one terminal of the power supply or indirectly, during a test mode, through a fault detection circuit which is also connected to the print head. The fault detection circuit includes a constant voltage source, preferably formed of series-connected diodes, through which power flows to the print head. Current passing through the constant voltage source activates a photocoupler having an output the voltage of which determines whether a current is or is not flowing into the print head. A CPU which controls overall operations in the printer monitors the photocoupler and selects either a normal printing mode or a print head test mode.

Abstract: A connecting apparatus includes a connecting conductor for connecting a supporting insulator supporting an overhead transmission line and a lightning arrester through a disconnecting member. The connecting conductor includes at least first and second conductor segments having given lengths. The first conductor segment connected to the lightning arrester is greater in bending strength than the second conductor segment connected to the disconnecting member.

Abstract: In the known electrical mobility analyzer, a novel means for charged particle detection instead of measuring the low level current carried by the particles is provided. This detection is based on the burst corona occuring from a positive corona electrode applied with a voltage slightly lower than its onset voltage at an instant when a negatively charged particle arrives at the tip of the corona electrode. This detection detects and counts the burst corona pulses produced by the particles negatively precharged.

Abstract: An arrangement for a tactile sensing system involved in the determination of object shape, contour, orientation and detection of slip finding one use in real time control of robotically manipulated tools. The sensor uses contact between the object and a gripper upon which the sensor is disposed wherein the object surface forms one plate of the sensing electrode.

Abstract: A test module incorporating a unique diagnostic circuit for monitoring the magnitude of electrical parameters existing between an electrical driver such as the electronic control module (ECM) of an automotive vehicle and an electrical load in the vehicle's electrical system. The circuit employs a visual indicator connected to a point adjacent the driver to provide a visual signal when the voltage at the point of connection lies within a predetermined range with respect to electrical ground. An additional visual indicator, separate from the first, is connected to a point adjacent to the electrical load, and provides a visual signal when the voltage at its point of connection lies within a predetermined range with respect to electrical ground. A third visual indicator is connected between the driver and load, and provides a visual signal in response to current flowing between the driver and load.

Abstract: Fault currents in the phases of a three-phase supply are detected by transformers 28 in respective phase links 14 and are counted by associated circuits 24 when any one of the circuits 24 reaches a predetermined count level, or when there is a fault condition, a low VA trip coil 42 is energized so as to release latches which hold the phase links 14 in their operative positions and thereby cause all three links 14 to drop out together.

Abstract: An adaptor for use in conjunction with an internal combustion engine having a capacitor discharge ignition system provides a substitute high voltage pulse coincident with the high tension pulse of the engine ignition system but having a period which is sufficiently prolonged to enable a conventional engine analyzer to be used to measure the usual engine parameters.

Abstract: A protective apparatus for use in an A.C. electrical power system with a circuit breaker for connecting and disconnecting first and second electrical conductors that are electrically energizable, the conductors normally having a negligible phase difference of electrical energization when the circuit breaker is closed, and the circuit breaker having auxiliary contacts defining the state of the circuit breaker as open or closed. The protective apparatus includes a circuit responsive to the auxiliary contacts for producing a first signal representative of the state of the breaker as open or closed and another circuit connected to the circuit for producing the first signal and operable when the breaker is closed for generating a second signal when the phase difference of electrical energization of the first and second electrical conductors exceeds a predetermined value. A further circuit provides an indication of malfunction of the circuit breaker when the second signal occurs.

Abstract: A solid disk surface unit mounted in a glass or ceramic support surface, comprising a plate member of cast material with one or more resistive heating elements mounted to the underside thereof and a thermally conductive cover member enclosing the underside of the plate member with its peripheral edge in close thermal contact with the plate member near its periphery, is provided with a thermally responsive switching device thermally coupled to the cover member and adapted to respond to the surface temperature of the cover member at a point relatively remote from its peripheral edge. The switching device is operative to remove power from the resistive heating elements of the surface unit when the sensed cover member temperature exceeds a predetermined threshold temperature, thereby protecting the glass support surface from damage due to thermal stresses resulting from hot spots occurring near the periphery of the surface of the plate member.

Abstract: A frequency domain sensing system is disclosed for sensing the position of a high energy beam of charged particles traveling within a housing which comprises a plurality of sensors positioned in the wall of the housing radially around the axis of the beam. Each of the sensors further comprises a first electrode of predetermined shape received in a bore in the housing to define a fixed capacitance and an inductance structure attached to the electrode to provide an inductance for the sensing means which will provide an LC circuit which will resonate at a predetermined frequency known to exist in the beam of charged particles. The sensors are further provided with tuning apparatus associated with the inductance structure to vary the amount of the inductance to thereby tune the sensors to the predetermined frequency prior to transmission of the signal to signal detection circuitry.

Abstract: The severity of the problems of transmitting high speed data over a regular twisted wire pair are legendary. These problems arise from a variety of conditions, including the capacitance of the wire (which increases with length) and the propensity of unshielded wire to pickup high induced voltages. An arrangement is disclosed that is suitable for short, as well as long, wire distances and which also effectively eliminates the interference problem caused by induced voltages, including those causes by electrostatic discharge. This arrangement passes two twisted wire pairs through a series of ferrite cores. The twisted wire pairs coming out of the ferrite cores are terminated such that one of the pairs is connected to ground while the signal carrying twisted pair is connected to a small signal balun coil, pulse shaping circuit and low pass filter.

Abstract: A heater for presenting an object to be heated on a carrier to a pair of heating structures which open from an initially closed position to receive same. The initial position of the carrier results in the heating structures being together initially and its motion then results in opening them to receive the object depending on the position reached by the carrier. The closing of the heating structures, due to further motion of the carrier, about the object to thereby envelop it reduces heating losses during the heating of the object.

Abstract: An integrated circuit switch made with CMOS processes contains a high voltage, high current field effect output transistor. The output transistor serves as a switch and is connected in series with an external load which is to be controlled by the switch. The integrated circuit also contains over current protection circuits and over temperature protection circuits. A circuit also provides fault indications which can be used to determine whether the over current or the over temperature limits were exceeded to shut off the switch.

Abstract: A power switching circuit for switching power repetitively to a load at a relatively low frequency employs a power switching device which is driven across an isolating transformer interface. The drive signals are high frequency pulse signals which are modulated with the low frequency switching information, the modulations being detected in the secondary circuit of the transformer. Such an arrangement affords isolated driving with fast switching edges and requires only a small transformer. Power for the detection circuit is derived by rectification of the high frequency signals induced in the transformer secondary.

Abstract: An integrated circuit for protecting subscriber lines against overvoltages includes a semiconductor body; a field-controllable thyristor having a gate electrode, an anode electrode and a cathode electrode, the gate electrode being insulated from the semiconductor body; a resistor connected between the cathode electrode and the gate electrode; a series circuit of Zener diodes connected between the gate electrode and the anode electrode, each of the Zener diodes having an anode electrode and a cathode electrode; and short circuit jumpers each being connected between the anode electrode and the cathode electrode of a respective one of at least part of the Zener diodes; at least part of the jumpers being interrupted corresponding to a predetermined breakdown voltage of the series circuit; and the thyristor having a larger breakdown voltage than the combined breakdown voltages of the Zener diodes of the series circuit of Zener diodes.

Abstract: A hermetically sealed package for a power semiconductor wafer is provided comprising substantially entirely silicon materials selected to have coefficients of thermal expansion closely matching that of the power semiconductor wafer. A semiconductor wafer such as a power diode comprises a layer of silicon material having first and second device regions on respective sides thereof. An electrically conductive cap and base, each including a layer of silicon material, are disposed in electrical contact with the first and second regions of the semiconductor device, respectively. An electrically insulative sidewall of silicon material surrounds the semiconductor wafer, is spaced from an edge thereof, and is bonded to the cap and base for hermetically sealing the package. An electrical passivant is disposed on an edge of the semiconductor wafer adjoining the first and second device regions for preventing electrical breakdown between the cap and base.

Abstract: Automatic switching apparatus for a hand held electrically operated appliance such as a pressing iron. A motion sensor and an electronic timer cooperate to automatically shut off the iron if the iron remains stationary for a predetermined period of time. A simplified mechanism is manually operable in the event the user desires to reactivate the iron. A circuit board mounting simplified electronic circuitry is located within the handle of the iron. An appropriate indicator informs the user whether the iron is in the active mode or in the inactive mode.