Working principle of gas discharge lamp

Gas discharge lamp
Gas discharge lamp is a lamp that emits light by gas, metal vapor or a mixture of several gases and metal vapor. An electric light source that converts electrical energy into light through gas discharge. There are many types of gas discharge, and the most commonly used are glow discharge and arc discharge (see arc discharge). Glow discharge is generally used for neon lights and indicator lights. The arc discharge can have a strong light output, and the lighting source uses arc discharge. Fluorescent lamps, high-pressure mercury lamps, sodium lamps and metal halide lamps are the most widely used gas discharge lamps for lighting. Gas discharge lamps are widely used in industrial, agricultural, medical and health and scientific research fields.

Working principle of gas discharge lamp
The working principle of the gas discharge lamp is actually very simple. Its discharge light-emitting process can be divided into three stages. As long as the discharge lamp is connected to the working circuit in the first stage, a stable self-sustained discharge will be generated, which converts the electrical energy into kinetic energy of free electrons; In the second stage, the fast free-moving electrons will collide with the atomic gas in the air, thereby converting the kinetic energy of the free electrons into the internal energy of the gas atom; in the third stage, when the gas atom returns to the ground state, it will convert the internal energy For the release of light radiation; after the above three stages, the process of gas discharge and light emission is completed, and the lamp will continue to emit light.

Working principle of high-strength gas discharge lamp
When the lamp starts, an arc is generated between the electrodes at both ends of the arc tube. Due to the high temperature of the arc, the sodium amalgam in the tube is heated and evaporated into mercury vapor and sodium vapor. During the movement of the cathode toward the anode, the discharge material impacts Atoms get energy to generate ionized excitation, and then return from the excited state to the stable state; or from the ionized state to the excited state, and then back to the endless cycle of the pentylene. The excess energy is released in the form of light radiation, and light is generated. . The vapor pressure of the discharge substance in the high-pressure sodium lamp is very high, that is, the density of sodium atoms is high, the number of collisions between electrons and sodium atoms is frequent, so that the resonance radiation spectrum is widened, and the radiation of other visible spectrum appears, so the light color of the high-pressure sodium lamp is better than Low pressure sodium lamp.

High pressure sodium lamp is a high intensity gas discharge bulb. Due to the negative resistance characteristics of gas discharge bulbs, if the bulb is connected to the grid alone, its working state is unstable. As the discharge process continues, it will definitely cause the current in the circuit to rise indefinitely, and finally to the light or the circuit. Parts and components are burned by overcurrent.