Abstract: A microwave oven is described suitable for use on transports where DC power is available. The microwave oven employs a first inverter to generate internal AC power that is then used to operate the microwave components other than the magnetron microwave source. The internal AC power is passed with relatively low current through the oven interlocks to activate and drive a power inverter that, through an additional output transformer winding, delivers high voltage power to the magnetron. In a preferred embodiment a relay, that is connected to sense when external AC power is available, causes an automatic switching that decouples the internal AC power from the power inverter to enable conventional operation from external AC line power. When external AC line power is no longer applied, the microwave oven automatically switches to operate from the available DC power. An efficient cooling fan is provided that is driven by a DC motor.

Abstract: A high voltage switch for use in electrophoresis equipment is described. A solid state switch element is triggered by a continuous DC voltage derived from an isolated and rectified AC trigger signal. The gate of solid state element is connected by a low impedancy path to ground when the AC signal ceases.

Abstract: In an apparatus for electrophoresis, using a support for a gel and a liquid buffer, a plurality of driving electrodes arrayed in spaced relation to one another so as to contact the medium, and a plurality of sensing electrodes arrayed in spaced relation to one another and the driving electrodes so as to contact the medium. Each sensing electrode is preferably radially inward of and paired with a single one of the driving electrodes. Means are provided respectively for providing electrical potentials to be applied to selected ones of the driving electrodes, for applying the provided potentials, for sensing electrical potentials at selected ones of the sensing electrodes, and for adjusting the applied potentials to maintain the sensed potential at a selected value at a sensing electrode of each pair. The apparatus may be programmably controllable so as to enable an electric field to be modulated in amplitude and direction, as a function of time.

Abstract: The present invention relates to a process and apparatus for controlling an electromagnetic casting system. The process and apparatus utilize at least one sense loop and an electrical parameter relating to the sense loop, e.g. the mutual inductance between the sense loop and a containment inductor, to control during casting the height of the contained head of molten material and/or the ingot size. In a first embodiment, a sense loop is positioned in the air gap between the containment inductor and the outer surface of the forming ingot or the molten metal head, preferably in a location in the vicinity of the liquid-solid interface. In a second embodiment, a plurality of sense loops are used to control the casting system.

Abstract: A drive circuit is disclosed which includes a converter that provides current pulses that charge a capacitive electroluminescent lamp to produce light and a switching circuit that switches a predetermined number of successive current pulses at high frequency for progressively charging the electroluminescent lamp. The switching circuit also reverses the polarity of the electroluminescent lamp at low frequency when the electroluminescent lamp discharges at the end of a predetermined number of successive current pulses and before the electroluminescent lamp charges again by current pulses produced by the converter. The switching circuit is connected to and is responsive to signals provided by the timepiece frequency divider circuit and the converter is connected to the timepiece battery for stepping up the battery voltage to provide for the charging current pulses. The EL lamp is used as its own storage capacitor and receives substantially all of the energy provided by the converter.

Abstract: An apparatus and process for casting metals wherein the molten metal is contained and formed into a desired shape by the application of an electromagnetic field established by an inductor. The height of the liquid metal head, the location of the liquid-solid interface at the periphery of the forming ingot, and/or variations in the values of these parameters is displayed during the casting run by a system which monitors the in-phase component of the voltage across the inductor to determine variations in the total equivalent series resistance of the electromagnetic casting system as seen by the inductor.

Abstract: A multi-strand apparatus and process is provided for casting molten materials into ingots of desired shape. The apparatus comprises a plurality of devices for receiving and electromagnetically forming the molten material into desired shape. Each of the receiving and forming devices includes an inductor for applying a magnetic force field to the molten material. The inductor in operation is spaced from the molten material by a gap extending from the surface of the molten material to the opposing surface of the inductor. An alternating current applying device sends current to its associated inductor to generate the magnetic force field. Circuitry associated with each of the inductors senses variations in their respective gaps. The improvement comprises a pulse width modulating circuit associated with said gap variation sensing circuitry being connected to the alternating current applying device for controlling the application of alternating current to the inductor.

Abstract: An apparatus and process for casting metals wherein the molten metal is contained and formed into a desired shape by the application of an electromagnetic field. The apparatus includes an inductor and a non-magnetic shield. Changes in the location or the location of the top surface of the molten metal head are continuously displayed during the casting run by monitoring electrical parameters of the electromagnetic casting system including at least one electrical parameter of the non-magnetic shield.

Abstract: An electromagnetic casting process and apparatus utilizing an active transformer-driven copper shield. The shield is actively driven with a voltage out of phase with the voltage in the containment inductor with the result that a bucking current is produced in the shield which is out of phase with the current induced in the shield by the inductor. An active transformer-driven duplex variable impedance shield is also disclosed.

Abstract: A multi-strand process is provided for casting molten materials into ingots of desired shape. The process uses two inductors for receiving the molten material and applying the first and second electromagnetic force fields to form the molten material into the ingots. The inductors are located adjacent each other so that the first and second force fields interact with each other. A first device is associated with one of the inductors for applying a first alternating current at a first desired frequency to an associated inductor to generate the first magnetic force field. A second device is associated with the other of the inductors for applying a second alternating current at a second desired frequency to generate the second magnetic force field. The second frequency is set to a desired value in relation to the first frequency in order to control the first and second resulting containment currents circulating in the molten material.

Abstract: A multi-strand apparatus and process for casting molten material into at least two ingots of desired shape. Structure is provided for receiving and electromagnetically forming the molten material into ingots of desired shape. Each of the receiving and forming structures includes an inductor for applying an electromagnetic force field to the molten material. When the inductor is in operation, it is spaced from the molten material by a gap extending from the surface of the molten material to the opposing surface of the inductor. The improvement comprises a device for distributing a common alternating current to the inductors to generate the magnetic fields. A device is provided for minimizing variations in the gaps during operation of the casting apparatus.

Abstract: A multi-strand apparatus and process for casting molten material into ingots of desired shape. A plurality of structures are provided for receiving and electromagnetically forming the molten material into the desired shape. Each receiving and forming structure includes an inductor for applying a magnetic force field to the molten material. When the inductor is in operation, it is spaced from the molten material by a gap extending from the surface of the molten material to the opposing surface of the inductor. Structure is provided for distributing a current in the inductor to generate the magnetic field. The improvement comprises a device arranged below the inductor for modifying the current distribution in the inductor to minimize the variations in the gap.

Abstract: An electromagnetic casting process and apparatus utilizing an active transformer-driven copper shield. The shield is actively driven with a voltage out of phase with the voltage in the containment inductor with the result that a bucking current is produced in the shield which is out of phase with the current induced in the shield by the inductor. An active transformer-driven duplex variable impedance shield is also disclosed.

Abstract: An apparatus for casting metals wherein the molten metal is contained and formed into a desired shape by the application of an electromagnetic field. A control system is utilized to minimize variations in the gap between the molten metal and an inductor which applies the magnetic field. The gap or an electrical parameter related thereto is sensed and used to control the current to the inductor.

Abstract: An electromagnetic casting process and apparatus utilizing an active transformer-driven copper shield. The shield is actively driven with a voltage out of phase with the voltage in the containment inductor with the result that a bucking current is produced in the shield which is out of phase with the current induced in the shield by the inductor. An active transformer-driven duplex variable impedance shield is also disclosed.

Abstract: In order to provide a tachometer which is accurate and easy to read, a number of light-emitting diodes is arranged in a row, each diode representing a predetermined increment of speed, rotational speed is measured and used to generate pulses, at a proportional rate, which are then decoded and used to drive the light emitting diodes over a predetermined time span, the diodes being lighted repeatedly in sequence at a rate exceeding the response time of the eye so as to present a flicker-free bar graph type display showing rotational speed.

Abstract: An apparatus for casting metals wherein the molten metal is contained and formed into a desired shape by the application of an electromagnetic field. A control system is utilized to minimize variations in the gap between the molten metal and an inductor which applies the magnetic field. The gap or an electrical parameter related thereto is sensed and used to control the current to the inductor.

Abstract: An improved spark advance circuit for use in an electronic ignition system for an internal combustion engine in which pulses generated in a pickup synchronized with the engine crankshaft are fed to a circuit for generating a voltage proportional to the desired advance and to a phase locked loop which is adapted to generate, at its output, a ramp synchronized with the input pulses, with the ramp output and proportional voltage supplied to a comparator, the output of which generates firing pulses which are advanced as a function of engine operation for use in the electronic ignition system.

Abstract: An apparatus and process for casting metals wherein the molten metal is contained and formed into a desired shape by the application of an electromagnetic field. A control system is utilized to minimize variations in the gap between the molten metal and an inductor which applies the magnetic field. The gap or an electrical parameter related thereto is sensed and used to control the current to the inductor.

Abstract: An apparatus and process for casting metals wherein the molten metal is contained and formed into a desired shape by the application of an electromagnetic field. The apparatus includes an inductor and a non-magnetic shield. Changes in the location or the location of the top surface of the molten metal head are continuously displayed during the casting run by monitoring electrical parameters of the electromagnetic casting system including at least one electrical parameter of the nonmagnetic shield.