Abstract: The method and the device for carrying out the method are used for producing transformers (27, 28, 29) which are filled with insulating means, especially transformers for distribution systems. In the case of the method, solid insulation of the transformers is dried in the device before addition of an insulating means, in that the low-voltage windings are short-circuited in every transformer, and the parallel-connected high-voltage windings (30, 31, 32) are heated by means of a low-frequency AC current. In this case, the mean temperature of the windings of the transformers is determined at the same time by measuring the low-frequency AC current, in order thus to make it possible to dry the solid insulation well.

Abstract: A plasma arc cutting machine which utilizes oxygen as a working gas is controlled to provide: a long electrode life without serious electrode wear even if the starting operation of the arc is repeated frequently; a smooth transition from a pilot arc to a main arc even when a thin plate is cut; and a low noise characteristic. A first stop valve (4) is connected in parallel with a serially connected second stop valve (7) and a gas flow regulating means (6) between a supply of working gas and a plasma torch (1). In response to a start signal S.sub.T, the second stop valve (7) is opened so as to supply the working gas at a small flow rate Q.sub.P to the plasma torch (1) via the gas flow regulating means (6). After a pilot arc is started, the first stop valve (4) is gradually opened so as to gradually increase the flow rate of the working gas from the small flow rate Q.sub.P up to a normal flow rate Q.sub.M, and at the same time, the pilot current is gradually increased from an initial pilot current level I.sub.

Abstract: A laser welder is provided comprising an optical fiber, a wheel including a slot for receiving an article to be welded, the optical fiber mounted to and wound upon the wheel as the wheel is rotated to bring the fiber around the article, and a sleeve for sealing to the article to establish a chamber surrounding the weld zone, the sleeve having a curved window for transmitting the laser light from the fiber to the weld zone. In another aspect, the invention provides the sealing sleeve for use in laser welding. The sleeve preferably includes a ring deformable to clamp the sleeve to the article and center the article along an axis of the sleeve. A pump is preferably also provided which removes oxygen from the weld zone chamber, so that pressurized inert gas can be introduced to reduce oxidation and vaporization. In a further aspect, the invention relates to a method of welding articles.

Abstract: Heating pads using positive temperature coefficient (PTC) resistance material are subject to fire risk if one of the conductor wires between which the PTC material extends should break and produce an electric arc. Protection by fuse and a fuse-blowing circuit responsive to fire detection must allow for an immense inrush of current when the cold pad is turned on. A heat setting control using a microprocessor can reduce the fuse rating by chopping the a.c. heating current for a short start-up period following with full-on feed until the heat setting is reached. The presence of a microprocessor allows response to a safety circuit that detects a break in a heater feed or return conductor before much excess heat develops, so that the microprocessor can turn off the heater switch. That response is so quick that it can be confirmed by repeated detection after very short pauses before the heater switch (a triac) is turned off.

Abstract: A device (1f), which is e.g. provided as an overheating protection means for detecting the temperature on a heating device (4f), apart from a temperature sensor (3f), also has an insulating connecting piece (20f) with all the connecting elements (23f) necessary for the electrical connection of the heating device (4f), in such a way that these connecting elements (23f), following the fastening of the device (1f) to the heating device (4f), are accessible directly adjacent to the outer circumference thereof and to the associated face (31f) of a device base (19f), so as to produce the necessary connections.

Abstract: A solid state electronic device using single electrons to convey informat. A cluster of pure carbon atoms, commonly known as a fullerene, is used to trap a single electron tunneling through an insulating material located between conductive layers of the device.

Abstract: A heating apparatus comprising a heating member, energization element for energizing said heating member, a temperature detection member for detecting a temperature of said heating member, a first switching element for turning on/off energization by said energization means on the basis of the temperature detected by said temperature detection member, abnormal current detection element for detecting an abnormal current flowing through said heating member, a second switching element for turning off energization by said energization element, and energization stop member for operating said second switching element to turn off energization.

Abstract: Heating pads using positive temperature coefficient (PTC) resistance material are subject to fire risk if one of the conductor wires between which the PTC material extends should break and produce an electric arc. Protection by fuse and a fuse-blowing circuit responsive to fire detection must allow for an immense inrush of current when the cold pad is turned on. A heat setting control using a microprocessor can reduce the fuse rating by chopping the a.c. heating current for a short start-up period following with full-on feed until the heat setting is reached. The presence of a microprocessor allows response to a safety circuit that detects a break in a heater feed or return conductor before much excess heat develops, so that the microprocessor can turn off the heater switch. That response is so quick that it can be confirmed by repeated detection after very short pauses before the heater switch (a triac) is turned off.

Abstract: A plasma torch incorporating an arc forming a chamber in which a cathode cooperates with an anode to form a plasma arc. A splitter is connected to the arc forming chamber and comprises a plurality of passages arranged about a core region, the passages leading from the arc forming chamber into a nozzle passage extending along the axis of the arc forming chamber. A feed passage passes through the core region, opening co-axially with the longitudinal axis of the torch, in or about the region of coalescence of the plasma stream exiting the splitter passages. Feedstock material, such as powder, is fed through the feed passage into the coalesced plasma stream in an axial direction and in its direction of travel.

Abstract: An improved image heating apparatus using a plasma lamp is disclosed. The apparatus comprises at least one rotary elliptical mirror having a reflection surface of a rotary elliptical body at the inside; a plasma lamp disposed at a first focal point of the rotary elliptical mirror; a member for supporting the plasma lamp; an electric wave shielding member provided inside the rotary elliptical mirror; a cavity resonator defined by the rotary elliptical mirror and the electric wave shielding member, and adapted to accommodate the plasma lamp; a high frequency oscillator adapted to supply electromagnetic wave to the cavity resonator via a wave guide; and a test sample disposed at a second focal point of the rotary elliptical mirror.

Abstract: A surface treatment nozzle for laser irradiation, with the supply of material in powder form is characterized in that it is essentially constituted, on the one hand, by a nozzle body (1) provided with a truncated conical passage (2) that converges in the direction of the outlet of the nozzle (3) along the propagation axis (6') of the laser beam (6) and, on the other hand, by a coaxial injection device (4) for guidance of the materials (5) in powder form carried by a transport fluid within the nozzle body (1) so as to improve the interaction between the incident laser beam (6) and the materials (5) in powder form.

Abstract: To eliminate pulsating current of vaporized gas by controlling a heater by means of a phase control, instead of controlling the heater by means of an on-off control which causes the vaporized gas to become a pulsating current, in a vaporized gas cooling apparatus using heater heating used in a thermal analysis apparatus and the like. By performing a phase control of the sine wave of the alternating power source by means of a thyristor and supplying power to the heater the duration of control at a time is reduced to as short as 10 msec (in case of 50 Hz). Accordingly, a filter effect is obtained by the fact that a changing speed of the heater temperature and a vaporization speed of coolant are too slow to follow the control action which prevents vaporized gas to become pulsating current. Since vaporized gas coming out is not a pulsating current, using this for cooling makes less fluctuation of temperature and makes the temperature more stable.

Abstract: An electron beam source assembly includes a water cooled crucible positioned substantially flush with the top of the block. A magnet is attached to each long sides of the rectangular block to establish parallel opposed pole magnets with the crucible therebetween. A smaller magnet is attached to each end of each longitudinal magnet to form a second and a third parallel magnet pair. The six magnets produce plano-convex magnetic field lines above the crucible, and additional plano-convex field lines of increased field strength extending outwardly from the end of the block having the four magnets. A magnetic base plate provides a low reluctance path to decrease magnetic flux at the crucible.

Abstract: A high frequency, high voltage starting circuit for a plasma arc cutting torch is constructed and operated with isolation between a pilot arc circuit and a transfer arc circuit. The duration and value of the energy flow in the pilot arc after initiating the HFHV signal are controlled electronically. The maximum value is sufficient to initiate and support the pilot arc and its transfer. The duration is sufficiently long to allow the pilot arc to transfer, but sufficiently short that nozzle wear is reduced. In the preferred form both circuits have a common D.C. power supply and independent surge injector circuits each formed by a resistor and surge capacitor connected in parallel with the power supply. An L-C loop in the pilot arc circuit maintains a generally constant current output on discharge.

Abstract: A cooking appliance has a heater for cooking, and a switch which generating an operational signal. The cooking appliance automatically turns off the heater a predetermined time after a last pressed switch, i.e., automatic power off function. A caution lamp indicates that the heater will automatically be turned off a minute prior to the automatic power off function.

Abstract: An electrode assembly having a tubular body portion is positioned in the head of a plasma arc torch and supports an electrode element spaced from a nozzle by an arc chamber. A gas is ionized in the arc chamber when an electric arc is initiated between the electrode element and the nozzle. The electrode element is retained in a post extending up from the bottom wall of the electrode body portion. The post has an extended exterior surface to increase the surface area in contact with coolant that circulates downwardly through the electrode body portion into surrounding relation with the post. The extended surface area of the post promotes heat transfer from the electrode element to the coolant and extends the operational life of the electrode element.

Abstract: An apparatus for preparing a medium for use in a printing process supports the medium (2) for rotation about an axis. A head (6) is mounted for movement parallel to the axis and includes means to direct a laser beam onto the surface of the medium. The laser beam engraves or exposes the series of cell sites (c) around the medium and an acousto-optic modulator (12) positioned in the path of the laser beam deflects the beam substantially in the direction of rotation of the medium (2). In a preferred example the beam tracks the surface of the medium at a speed matched to that of the medium so as to keep the beam stationary on the cell site while that site is being engraved or exposed. The beam may also be deflected to skip backwards or forwards over immediately adjacent cell sites.

Abstract: A toasting machine comprising heating elements, an on/off switch for initiating a toasting cycle, a toast colour selection knob for setting a selected time period for a toasting cycle, a timing circuit arranged to measure the elapsed time since a previous toasting cycle and including time booster means, a control circuit responsive to the toast colour selection setting and the timing circuit, a connection line and plug for connecting the toasting machine to an electrical power supply so as to supply power to the heating elements on initiation of a toast cycle by the on/off switch and under control of the control circuit, a temperature measuring device arranged to measure the temperature of the toasting machine and supply a temperature representing signal to the control circuit, the control circuit being arranged to control the timing of a current toasting cycle in dependence both on the setting of the toast colour selection switch and on the timing circuit, so that the toasting cycle time period during which

Abstract: A power supply for a thruster for space applications (e.g., an arcjet thruster) comprises a series/parallel resonant converter wherein the load quality (Q) factor of the resonant tank circuit inherently varies with arc voltage so as to accommodate changes in arc voltage from initiation thereof through steady-state operation. Effectively, the resonant tank circuit acts as a ballast by matching the arc during initiation thereof through steady-state operation. Furthermore, the resonant converter operates in a soft-switching, low-voltage switched mode so as to maximize efficiency.

Abstract: A plasma arc torch uses a mix of reactive and reducing gas flows to cut sheets of stainless steel, aluminum and other non-ferrous metals. The reducing gas flow to the cut is varied as a percentage of the total gas flow to maintain a reducing atmosphere down through the cut, but to leave a predominantly oxidizing atmosphere at the intersection of the cut and the bottom surface of the sheet being out. These flows can also be characterized as either a plasma gas flow, one that forms the arc, or a shield gas flow that surrounds the arc. The reactive gas is preferably a flow of air, oxygen, nitrogen, carbon dioxide or a combination of these gases. The reactive gas is usually in the plasma gas flow, whether alone or mixed with other gases. The reducing gas is preferably hydrogen, hydrogen 35, methane, or a mixture of these gases. For aluminum, the reactive gas is preferably air or nitrogen and the reducing gas is preferably methane or a mixture of methane and air.