How does cold cathode work?

A cold cathode lamp functions by using electricity emitted from cathodes to excite mercury vapors using the process of inelastic scattering in order to create fluorescence, just as a typical linear fluorescent does.

What is hot cathode and cold cathode?

In vacuum tubes and gas-filled tubes, a hot cathode or thermionic cathode is a cathode electrode which is heated to make it emit electrons due to thermionic emission. This is in contrast to a cold cathode, which does not have a heating element.

Which lamp is a cold cathode lamp?

Cold cathode lamps: Neon lamp, neon sign tubes, sodium vapor lamp. Hot cathode lamps: mercury vapor lamp (medium pressure), and fluorescent tube (low-pressure mercury-vapor lamp).

Why magnetic field is used in cold cathode ionization gauge?

The magnetic field causes the electrons to move in tight spirals to and fro between the two cathode plates. In this way the number of ions per electron, between initial emission and eventual escape from the discharge to the anode, is much increased.

How do you improve the power factor in the fluorescent tube is?

The objective of the work is to improve the power factor of the compact fluorescent lamps (CFLs) by reducing the Total Harmonic Distortion (THD). The power factor is improved by using modified electronic ballast with passive valley-fill power factor correction circuit.

What is cold cathode ionization gauge?

In the cold cathode gauge (CCG) it is a circulating space charge current of electrons trapped in crossed electric and magnetic fields. Indications of both types of gauge are gas dependent. Relative sensitivities for different gases are not the same for different HCGs or CCGs, or for HCGs compared to CCGs.

How does Mcleod gauge work?

Mcleod Gauge works on the principle of Boyle’s Law. Boyle’s Law states that if the temperature and amount of gas remain unchanged, the absolute pressure exerted by a given mass of gas is inversely proportional to the volume it occupies.

How does a Convectron gauge work?

The Convectron Gauge operates like a standard Pirani gauge, which employs the principle of a Wheatstone bridge to convert pressure to voltage, but uses convection cooling to enable accurate pressure measurement, when properly calibrated, from 10–4 to 1000 Torr.