Vacuum variable capacitors - Cixi Riyi Capacitor Factory

Blog

Vacuum variable capacitors

Inside a vacuum capacitor, two metal (copper usually) electrodes are separated by a vacuum. The outer part of the capacitor is made from either glass or ceramic. They usually have a low capacitance in the range of 10 to 1000 pF and high voltages, typically 5000 volts and compensation capacitor higher. Vacuum capacitors find wide application in industrial applications of radio frequency energy. They are used in equipment such as high powered broadcast transmitters, Amateur radio RF Amplifiers and large antenna tuners. Vacuum capacitors can also be used as the impedance variation part in automatic matching. Variations of vacuum capacitors include fixed and variable. The main difference between fixed and variable is that variable vacuum capacitors are able to be adjusted.

Vacuum variable capacitors need to be able to handle high voltages. A typical high power ham radio or AM broadcast transmitter will have a dc potential of 1500 to 7500 V on the RF amplifier anode, dependent on the kind of tube. In the case of AM, this potential can double. Certain defects within the system may also increase RF voltages, so a variable capacitor used in the final amplifier anode circuit must be capable of withstanding these potentials.

Vacuum could possibly be probably the most good of dielectrics using a zero deprivation tangent. What this shows could possibly be the actuality that extremely significant powers could possibly be transferred with out considerable deprivation and heating; the products are self-healing subsequent moderate overloads. in comparison with other variable capacitors, vacuum variables, generally because belonging in the direction of the vacuum itself, really are a good offer more precise and stable. The sealed chamber shows the dielectric constant persists to be precisely the same exact over a wider range of operating conditions. by method of using vacuum variable capacitors, designers are already in a location to create more compact transmitters that provide better, a good offer more dependable performance, and so are much less difficult to tune and retain in tune.

For significant energy transmitters collectively with other significant voltage capacitor applications, vacuum capacitors are employed for energy amplifier tank circuits, output of pi networks, neutralizing circuits, grid and plate blocking circuits, antenna coupling and "rejecter" tap circuits, pulse shaping inside the output circuit of magnetrons, feed-through capacitors for harmonic attenuation, dielectric heating provides tank circuits, low-inductance, high-current bypass applications, and non-magnetic capacitors for resonance imaging. Vacuum capacitors are employed in broadcast transmitters for prolonged wave, method wave (MW or AM), short wave, and VHF (FM and TV). additionally they serve in broadcast antenna systems, especially in AM directional antenna phasing systems, diplexers, triplexers and collection tuning units.

Pre Page: A Wide Variety Of Applications-Vacuum... Next Page: A Maxxis Ignitor Tyre

Product (82)

News (1)

Company workshop (7)

Blog (15)

Certificates (6)

Credit Report

Products Index

Company Info

Premium Related Suppliers

Blog