What is the purpose of a mercury arc rectifier?
The purpose of the Mercury Arc Rectifiers is to convert the incoming 415 volt alternating current from the National Grid, into 200 volts direct current for the museum’s historic motors and ancillary equipment.
Who invented the mercury arc rectifier?
Peter Cooper Hewitt
The mercury-arc rectifier was invented by US electrical engineer Peter Cooper Hewitt at the turn of the 20th century.
How does a mercury vapor rectifier work?
Operation of the rectifier relies on an electrical arc discharge between electrodes in a sealed envelope containing mercury vapor at very low pressure. When an arc is formed, electrons are emitted from the surface of the pool, causing ionization of mercury vapor along the path towards the anodes.
What is arc of mercury?
: an electric discharge through mercury vapor in a glass or quartz tube emitting a blue-green light rich in actinic and ultraviolet rays and used for various purposes (as for water sterilization, in photography, and in a rectifier)
Are mercury arc rectifier still in use?
The ignitor draws a small spark to ionise the mercury vapour, initiating the main arc. Mercury arc rectifiers have now been made totally obsolete by semiconductors, although there are a few still in service in old installations.
Who is invented mercury?
It is not known exactly when the planet was first discovered – although it was first observed through telescopes in the seventeenth century by astronomers Galileo Galilei and Thomas Harriot.
Are mercury arc rectifiers still used?
How does a selenium rectifier work?
Selenium rectifiers are made from stacks of aluminum or steel plates coated with about 1 μm of bismuth or nickel. A much thicker layer of selenium (50 to 60 μm) doped with a halogen is deposited on top of the thin metal plating. The selenium is then converted into polycrystalline gray (hexagonal) form by annealing.
Which rays are produced by arc of mercury or iron?
Ultraviolet rays They are part of the solar spectrum and can be produced by arcs of mercury and iron. They are used in medical applications and sterilisation processes.
What kind of valve for mercury vapor rectifier?
Steel-tank valves were used for higher current ratings above approximately 500 A. The earliest type of mercury vapor electric rectifier consists of an evacuated glass bulb with a pool of liquid mercury sitting in the bottom as the cathode. Over it curves the glass bulb, which condenses the mercury that is evaporated as the device operates.
Who was the inventor of the mercury rectifier?
The current is prevented from traveling backwards, so the effect is like that of a diode. The mercury-arc rectifier was invented by US electrical engineer Peter Cooper Hewitt at the turn of the 20th century. This revolutionary device is also known as the Hewittic rectifier, mercury-arc valve or mercury-vapor rectifier.
How does a mercury rectifier work at low pressure?
Operation of the rectifier relies on an electrical arc discharge between electrodes in a sealed envelope containing mercury vapor at very low pressure. A pool of liquid mercury acts as a self-renewing cathode that does not deteriorate with time.
What kind of rectifier is in Beromunster AM transmitter?
Mercury rectifier on display in the Beromünster AM transmitter in Switzerland, before being decommissioned. A mercury-arc valve or mercury-vapor rectifier or (UK) mercury-arc rectifier is a type of electrical rectifier used for converting high-voltage or high-current alternating current (AC) into direct current (DC).
