Abstract: An antenna module including a dielectric substrate having a long side and a short side, a ground electrode, a radiating element, a peripheral electrode, and a parasitic element. The radiating element is disposed to face the ground electrode. The peripheral electrode is disposed along the long side of the dielectric substrate and is electrically connected to the ground electrode. The parasitic element is disposed along the short side of the dielectric substrate and is disposed away from the radiating element. The radiating element is configured to emit radio waves in two polarization directions along the long side and the short side of the dielectric substrate. The shortest distance between the radiating element and the parasitic element is greater than the shortest distance between the radiating element and the peripheral electrode.

Abstract: In a microwave discharge light source apparatus for effecting discharge of an electrodeless discharge lamp held in a cavity which causes resonance by microwaves, the wall surface of the cavity resonator is constituted by a mesh and wires constituting the mesh, are electrically connected at each crossing point without resistance of contact. Effective discharging of the lamp is attainable and the cavity has a mechanically strengthened structure.

Abstract: A pulse arc welding machine in which the welding operations and welding current are controlled such that the molten portion of a wire electrode is not significantly splattered and the welding arc length and welding bead are uniform. The welding machine of the invention includes a wire electrode, a welding torch confronting a base material while being spaced therefrom, a shielding gas supplying unit for supplying a shielding gas to the welding area on the base material, and a wire feeding unit for feeding the wire electrode to the welding torch. A base current source supplies a base current between the wire electrode and base material with a pulse current from a pulse current source being imposed thereon. A pulse frequency varying circuit varies a number of pulses per unit time for the pulse current so that the number of pulses is proportional to the speed at which the wire electrode is fed thereby to set the average arc current.

Abstract: A microwave generated plasma light source including a microwave generator, a microwave cavity having a light reflecting member forming at least a portion of the cavity, and a member transparent to light and opaque to microwaves disposed across an opening of the cavity opposite the feeding opening through which the microwave generator is coupled. An electrodeless discharge bulb is disposed at a position in the cavity such that the cavity operates as a resonant cavity at least when the bulb is emitting light. In the bulb is encapsulated at least one discharge light emissive substance. The bulb has a shape and is sufficiently small that the bulb acts substantially as a point light source.

Abstract: A pulse arc welding machine including a wire electrode, a wire feeding unit for feeding the wire electrode to a base material, a base current source for supplying a base current between the wire electrode and the base material, a pulse current source for supplying a pulse current superposed on the base current, a detector for detecting the arc discharge voltage between the wire electrode and the base material, and a controller. The controller compares a detected output value from the detector with a preset reference value to thereby control the amount of heat applied to the wire electrode wherein the arc voltage between the wire electrode and the base material is maintained substantially at a value determined by the reference value.

Abstract: A pulse arc welding machine in which the repetition frequency of the pulse currect is unaffected by the frequency of the power source and the mean value of the pulse current applied can be accurately controlled over a broad range while the arcing is maintained stable. A pulse peak current supplying circuit is connected in series with an arcing region formed between a consumable wire electrode and a material to be welded between the output terminals of a standard direct current source while a base current supplying circuit is connected in parallel with the pulse peak current supplying circuit. The pulse peak current supplying circuit and the base current supplying circuit are both composed of a switching element such as a transistor coupled in series with an inductive element. Diodes are provided for suppressing high voltage transients in the circuit.

Abstract: An electrical welding device which requires no high frequency insulation and an electrical discharge gap for maintaining the arc discharge is made large. A main power source supplies an arc discharge current through an electrical conductor to the welding electrode. A high frequency electric power source applies a high-frequency high voltage between the electrode and the material to be welded to generate a high frequency discharge for arc ignition in the electric discharge gap. A high frequency magnetic choke element, which is preferably a plurality of stacked annular ferrite discs, surrounds a predetermined part of the electrical conductor. A high-frequency bypass capacitor is utilized to ground the electrical conductor between the magnetic choke element and the main power source.

Abstract: Typically, a bottom of a cup-shaped electrode opposes to that of a similar electrode through a predetermined gap and in a mixture of helium and hydrogen. A step-up transformer connected across an AC source through a resistor applies a voltage in excess of a discharge breakdown voltage for the gap across the electrodes to cause a pilot glow discharge between them before the source voltage reaches a glow hold minimum voltage for the electrodes. A rectified voltage resulting from a transformer connected across the resistor turns a bidirectional triode thyristor on to apply the source voltage across the electrodes through the conducting thyristor. This smoothly transits the pilot glow discharge to a glow discharge between the electrodes. The latter discharge heats a liquid forcedly flowing along inner surfaces of the electrodes. Also an auxiliary electrode can be operatively coupled to the electrodes to cause similarly a pilot glow discharge between it and either one of the electrodes.

Abstract: Typically, a bottom of a cup-shaped electrode opposes to that of a similar electrode through a predetermined gap and in a mixture of helium and hydrogen. A step-up transformer connected across an AC source through a resistor applies a voltage in excess of a discharge breakdown voltage for the gap across the electrodes to cause a pilot glow discharge between them before the source voltage reaches a glow hold minimum voltage for the electrodes. A rectified voltage resulting from a transformer connected across the resistor turns a bidirectional triode thyristor on to apply the source voltage across the electrodes through the conducting thyristor. This smoothly transits the pilot glow discharge to a glow discharge between the electrodes. The latter discharge heats a liquid forcedly flowing along inner surfaces of the electrodes. Also an auxiliary electrode can be operatively coupled to the electrodes to cause similarly a pilot glow discharge between it and either one of the electrodes.

Abstract: Typically, a bottom of a cup-shaped electrode opposes to that of a similar electrode through a predetermined gap and in a mixture of helium and hydrogen. A step-up transformer connected across an AC source through a resistor applies a voltage in excess of a discharge breakdown voltage for the gap across the electrodes to cause a pilot glow discharge between them before the source voltage reaches a glow hold minimum voltage for the electrodes. A rectified voltage resulting from a transformer connected across the resistor turns a bidirectional triode thyristor on to apply the source voltage across the electrodes through the conducting thyristor. This smoothly transits the pilot glow discharge to a glow discharge between the electrodes. The latter discharge heats a liquid forcedly flowing along inner surfaces of the electrodes. Also an auxiliary electrode can be operatively coupled to the electrodes to cause similarly a pilot glow discharge between it and either one of the electrodes.

Abstract: Typically, a bottom of a cup-shaped electrode opposes to that of a similar electrode through a predetermined gap and in a mixture of helium and hydrogen. A step-up transformer connected across an AC source through a resistor applies a voltage in excess of a discharge breakdown voltage for the gap across the electrodes to cause a pilot glow discharge between them before the source voltage reaches a glow hold minimum voltage for the electrodes. A rectified voltage resulting from a transformer connected across the resistor turns a bidirectional triode thyristor on to apply the source voltage across the electrodes through the conducting thyristor. This smoothly transits the pilot glow discharge to a glow discharge between the electrodes. The latter discharge heats a liquid forcedly flowing along inner surfaces of the electrodes. Also an auxiliary electrode can be operatively coupled to the electrodes to cause similarly a pilot glow discharge between it and either one of the electrodes.

Abstract: A microwave heating oven comprises an inner casing or particles as an inner casing which is made of a material being heated by microwave in which a material being heated is placed; an intermediate casing made of a refractory insulator which causes less microwave loss and which covers said inner casing or particles; and means for applying the microwave from outside of the intermediate casing into the inner casing or particles.The microwave heating furnace can be used for uniformly heating the material at high temperature with small electric power. A ceramic and a porcelain can be prepared by a household microwave oven as one of the microwave heating furnaces.

Abstract: A microwave generated plasma light source including a microwave generator, a microwave cavity having a light reflecting member forming at least a portion of the cavity, and a member transparent to light and opaque to microwaves disposed across an opening of the cavity opposite the feeding opening through which the microwave generator is coupled. An electrodeless discharge bulb is disposed at a position in the cavity such that the cavity operates as a resonant cavity at least when the bulb is emitting light. In the bulb is encapsulated at least one discharge light emissive substance. The bulb has a shape and is sufficiently small that the bulb acts substantially as a point light source.