Abstract:
A microwave oven using DC power which can endure strong vibrations and eliminate noise according to noise standards. The microwave oven includes at least one second choke coil which is arranged outside a magnetron filter box and connected in series to at least one first choke coil installed in the magnetron filter box. Each choke coil and a feed-through condenser constitute a low pass filter. The size of each of the first choke coil is reduced and the size of each of the second choke coil is increased, so as to endure the strong vibrations and eliminate the noise generated by a driving of a magnetron.
Abstract:
A magnetron including a tubular metallic container which is air-tightly connected to an anode, cathode leads for supporting a cathode with filaments being disposed in a central axial portion of the anode, a stem insulator formed with through holes through which the cathode leads pass, and external terminals formed with planar portions which are air-tightly connected to a surface of the stem insulator opposite to a surface facing the tubular metallic container and with connecting portions which are air-tightly connected to the cathode leads. The connecting portions are arranged to be bent in an axial direction of the cathode leads. It is possible to exhibit the effect of preventing vacuum break from occurring by oxidation or the like since the increase in the area of the connecting portions will result in elongation of the distance between the end portions of the connecting portions and the through holes.
Abstract:
An optical magnetron generator is provided which includes an anode and a collector separated by an anode-collector space, a pair of output terminals operatively coupled to the anode and the collector to provide an electrical power output based on an electric field generated across the anode-collector space. The optical magnetron generator further includes one magnet arranged to provide a dc magnetic field within the anode-collector space generally normal to the electric field, and a plurality or resonant cavities each having an opening along a surface of the anode which defines the anode-collector space; an input for receiving electromagnetic radiation from an external source and operatively configured to introduce the optical radiation into the anode-cathode space to establish a resonance electromagnetic field within the resonance cavities. A cathode for introducing electrons into the anode-collector space in proximity to the resonant electromagnetic filed, wherein the resonant electromagnetic field accelerates the electrons within the anode-collector space towards the collector onto which at least one portion of the electrons are collected.
Abstract:
A magnetron for a microwave oven includes a yoke, an anode cylindrical body installed inside the yoke, a plurality of veins mounted inside the anode cylindrical body, a filament installed in a center of the veins, and an upper magnet and a lower magnet respectively mounted on an upper side and a lower side of the anode cylindrical body. The magnetron also includes an upper pole piece and a lower pole piece respectively installed between the anode cylindrical body and the upper and lower magnets. A length (L) from an external tip of a central part of the upper pole piece to an internal tip thereof, on which a hollow part is formed, is adjusted to suppress harmonics in the magnetron. Thus, generation of the harmonics may be effectively attenuated, and an output of a microwave may be enhanced by preventing power consumption of the magnetron which may be large due to interrupting harmonics.
Abstract:
A microwave oven includes a direct current (DC) power supply unit which supplies DC power to a magnetron so as to suppress noise induced in a high voltage line. The DC power supply unit includes at least one rectifying diode and a choke coil. The rectifying diode rectifies high frequency alternating current (AC) power generated by a heater coil into the DC power to suppress noise induced in the high voltage line of a high voltage transformer. The choke coil forms ripples in the DC power and effectively prevents a moding of the magnetron, which is generated where a constant DC voltage is supplied.
Abstract:
An optical magnetron is provided which includes a cylindrical cathode and an annular-shaped anode coaxially aligned with the cathode. The anode may include a plurality of wedges arranged side by side to form a hollow-shaped cylinder having the anode-cathode space located therein, and each of the wedges includes a recess which defines at least in part a resonant cavity having an opening exposed to the anode-cathode space. The anode alternatively may include a plurality of washer-shaped layers stacked atop each other. Each of the layers includes a plurality of recesses along an inner diameter which are aligned with recesses of the other layers to define a plurality of resonant cavities along an axis of the cylinder each having an opening to the anode-cathode space.
Abstract:
An optical magnetron is provided which includes a cylindrical cathode having a radius rc, and an annular-shaped anode having a radius ra and coaxially aligned with the cathode to define an anode-cathode space having a width wa=ra−rc. The optical magnetron further includes electrical contacts for applying a dc voltage between the anode and the cathode and establishing an electric field across the anode-cathode space, and at least one magnet arranged to provide a dc magnetic field within the anode-cathode space generally normal to the electric field. A plurality of resonant cavities are provided with each having an opening along a surface of the anode which defines the anode-cathode space. Electrons emitted from the cathode are influenced by the electric and magnetic fields to follow a path through the anode-cathode space and pass in close proximity to the openings of the resonant cavities to create a resonant field in the resonant cavities. The resonant cavities are each designed to resonate at a frequency having a wavelength &lgr;, and circumference 2&pgr;ra of the surface of the anode is greater than &lgr;.
Abstract:
A fault-tolerant control system facilitates the closed loop control of a magnetron. The control system includes a transformer assembly for applying peak current to a magnetron, a pulse-forming network that conditions a transmit pulse, and a control circuit for adjusting the peak current applied to the magnetron. The control circuit includes a sample and hold circuit for comparing a signal representative of a detected peak current to a desired peak current level. The sample and hold circuit is coupled to a digital up/down counter circuit, and the output of the counter circuit is utilized to adjust the charge voltage of the pulse-forming network.
Abstract:
A noise filter of a high frequency generator reduces noise of a certain frequency band leaked from the high frequency generator using a structure in which a first core inductor, an air-core inductor and a second core inductor are connected in series to each other. The first and second core inductors have high frequency-energy absorbing members inserted thereinto, and the air-core inductor is not provided with a high frequency-energy absorbing member therein. The high frequency-energy absorbing member is made of one of iron oxide, tin alloy and ferrite. The high frequency-energy absorbing member is also provided with a sectional area in which noise of a frequency band of 400 MHz to 900 MHz is attenuated.
Abstract:
A power supply is provided for a lamp system. The power supply may include structure to switch from a high power level to a low power level. The high power level and the low power level together are a cycle that is repeated. The high power level may be higher than the conventional steady-state power level used for the same lamp system.