Color tubes (colored glass) have been made in the glass factory with yellow, red, blue and green pigments, which are all blown by hand, so the price is high and the diameter error is large. Neon lamp is a kind of cold anode light-emitting discharge device with long-distance discharge, which uses short-wave ultraviolet excitation phosphors (such as tungstate, borate, silicate, phosphate and other phosphors). Its luminous principle is that 254 mm ultraviolet rays are generated by low-pressure mercury discharge, and then all kinds of different phosphors are excited by the 254 mm ultraviolet rays, thus obtaining neon lights with dozens of colors. The principle of neon lamp is that the sealed glass tube is filled with neon, helium, argon and other gases. Two metal electrodes are installed at both ends of the tube, which are generally made of copper. The electrode leads are connected to the power supply circuit, and a high-voltage transformer is equipped to apply a voltage of 11~15kV to the electrodes. Because the gas in the tube is composed of countless molecules, molecules and atoms are neutral under normal conditions. Under the action of high voltage, a small amount of free electrons move to the anode, and the rapid dissociation of gas molecules excites electrons to accelerate their movement, which makes the gas in the tube conduct electricity and emit colored glow (also known as rainbow light). The luminous color of neon lamp principle is related to the gas used in the tube and the color of the lamp tube; Neon lamp principle If neon gas is filled in a light yellow tube, it will emit golden light, and if neon gas is filled in a colorless transparent tube, it will emit yellow and white light. Neon lamp principle to produce different colors of light, it is necessary to use many different colors of light tubes or put different gases into neon lamp tubes. Neon lamp is made of glass tube, which can be bent into any shape after firing, with great flexibility. By choosing different types of tubes and filling different inert gases, neon lamp can get colorful and multi-colored light. The structure and principle of neon lights are not complicated. In a glass tube with two closed ends, two electrodes are installed to pump out the air in the tube, and then a high-voltage direct current of more than 11,111 volts is applied between the two electrodes, so that the thin air in the tube will ionize and discharge, thus emitting light. If the air is pumped out and a small amount of different inert gas or mercury vapor is filled into the tube, the light will appear different colors: if neon gas is filled, it will emit orange light when it is discharged. ?