China manufacturer of magnetic ballasts for metal halide flood lights & hps flood lights

When the hps lamp is started, both ends of the arc tube between the electrodes, an arc is generated, the heat evaporation of mercury vapor and sodium vapor due to the high temperature of the arc tube sodium amalgam cathode emitted electrons to the anode during the movement, impact discharge substances atoms, to get the energy to produce ionization excitation. High pressure sodium discharge substance the high vapor pressure, i.e. high density of sodium atom, frequent collisions between the electron and the sodium atom, so that the spectral line broadening of the resonance radiation, there remaining visible spectrum of the radiation, and therefore the light color of the high-pressure sodium lamp is superior to low pressure sodium lamps.

 High pressure sodium lamp is a high-intensity gas discharge lamp. Since the gas discharge negative resistance characteristic of the lamp, if the lamp is individually connected to the grid, its working condition is unstable, as the discharge process continues, it will certainly lead to unlimited increase in the current circuit, and last until lighting or in the circuit zero, component is overcurrent burned.
High pressure sodium with other gas discharge lamp, working arc discharge status, volt – ampere characteristic curve of negative slope, the that lamp current rise, the lamp voltage has dropped. The constant power conditions, in order to ensure the lamp operated stably, the circuit must be one having a positive resistance characteristic of the circuit in series No piece to balance this negative resistance characteristic, stable operating current, the element referred to as a ballast or flow restrictor. Resistors, capacitors, receptors are willing limited flow role. Resistive ballast is small, cheap, and supporting the use of high-pressure sodium lamp will be difficult to start in the high heat resistance work, the need for a larger space for heat dissipation, power consumption, and will make the the circuit total lighting efficiency decline. It is generally in the DC circuit, lights flicker hundred AC circuit. Capacitive ballast unlike resistive ballast power consumption is large, low temperature rise, low power frequency, will produce a pulse peak current, the charging of the capacitor, causing great damage to the electrode, lights flashing, impact lamp life; work in the high-frequency circuit, voltage fluctuations can achieve the ideal state, the ideal ballast. Inductive ballast loss, impedance stabilization, resistance antibiotic deviation is small, long life, stability than the bulb resistive ballast, supporting the use of current and high-pressure sodium lamp ballasts are inductive ballast . The disadvantage than benzene and high prices. In addition, the electronic ballast has been started, its expensive and reliability with high pressure sodium lamps can not match, except special occasions, under normal circumstances, is rarely used. Therefore, before using the high-pressure sodium lamps must be in series with the HPS ballast bulb specifications. High pressure sodium lighting circuit is a nonlinear circuit, the power factor is low, consider pick compensation capacitor in the network in order to improve the power factor of the network.