Radio Frequency power supply

A 1- to 2-kW radio frequency power supply, either free-running or crystal-controlled, drives current through a water- or air-cooled copper tube that acts as the induction coil (often called a load coil). The oscillating current through the load coil produces an oscillating electromagnetic field. 

The tubular-type plasma reactor system used in the study consists of a reactor chamber, power supply, monomer feed, and pumping-out units, as depicted in Figure 19.1. One side of the glass tube is connected to a monomer inlet and the other side to a vacuum pump with O-ring joints. A radio frequency power generator of 13.56 MHz is coupled to two capacitive copper electrodes, which are 1 cm wide and 6 cm apart. The radio frequency power was controlled by an L-C matching network and monitored by power meter. 

A high-intensity, electrodeless ultraviolet source has recently been introduced. This UV source is distinguished from other conunercially available UV lamps by the fact that no electrodes are Inside the lamp. Electrical energy is supplied in the form of radio frequency power that is coupled into an evacuated quartz tube containing mercury and other additives. As compared to conventional medium-pressure mercury arcs with electrodes, the electrodeless system has several attributes that make it unique (17). These are summarized as follows (1) instant on-off (2) modular lamp design (3) increased lamp lifetime (4) variable spectrum (5) excellent energy conversion. 

The technique and past history of skull melting has been described in several articles from this and other laboratories.12-19 Basically, radio frequency power from a commercial power supply (50 KW at 3-5 MHz) is transferred to a work coil tightly wrapped about a skull crucible consisting of a set of cold fingers that... 

Power supply, x-ray tube, constant-potential, 245, 246 full-wave, 244, 245 half-wave, 244, 245 radio frequency, 149 three-phase, 246 Pre-amplifier, use, 60, 243 Precision, 266... 

Low-temperature glow-discharges were utilized to cause bond rupture in hexafluoroethane (11). In these experiments, the power to support the discharge was supplied by a radio-frequency discharge that delivered 25 W of power, at a frequency of 8.6 MHz, to the copper coil surrounding the Pyrex reactor (see Fig. 2). The load coil was indue-... 

Pulse-mode pyrolyzers include resistively-heated electrical filaments or ribbons and radio frequency induction-heated wires [841,842,846,848,849]. The filament or ribbon-type pyrolyzers are simple to construct. Figure 8.45, and typically consist of an inert wire or ribbon (Pt or Pt-Rh alloy) connected to a high-current power supply. Samples soluble in a volatile solvent are applied to the fileutent as a thin film. Insoluble materials are placed in a crucible or quartz tube, heated by a basket-lilce shaped or helical wound filiunent. The coated filament is contained within a low dead volume chamber through which the carrier gas flows, sweeping the pyrolysis products onto the column. The surface temperatui of the filament is raised rapidly from ambient temperature to He equilibrium pyrolysis temperature. This... 

These lamps are radio frequency (RF) powered, and can be easily controlled and switched. The power supply includes all electrical controls, interlocks, and the water cooling supply system. A complete system is shown schematically in Figure 3.4. 

Polystyrene capacitors have exceptionally low tan S values (< 10 q, making them well suited for frequency-selective circuits in telecommunications equipment. Polymer capacitors are widely used for power-factor correction in fluorescent lighting units, and in start/run circuitry for medium-type electric motors used in washing machines, tumble-dryers and copying machines for example. They are also used in filter circuits to suppress radio frequencies transmitted along main leads. Such interference noise may originate from mechanical switches, furnace controllers and switch mode power supplies it not only spoils radio and television reception but can also cause serious faults in data-processing and computer equipment. 

Operational environment checks should include those on power supplies, ambient temperature and humidity, vibration and dust levels, Electro-Magnetic Interference (EMI), Radio Frequency Interference (RFl), and Electrostatic Discharges (ESD) as relevant to the needs of the computer system. This list of operational environment requirements is by no means exhaustive, and may be extended or even reduced depending on what is known about the system. EMI and RFI might be tested with the localized use of mobile or cell telephones, walkie-talkie communications receivers/transmitters, arc welding equipment, and electronic drills. The aim is to test the vulnerability of the computer system to interference in situations that must be considered as normal working conditions. 

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