High pressure sodium lamp discharge materials vapor strain is very higher, namely high atomic density of sodium, sodium atoms and electron collision among the number of regular, the resonance radiation broadening of spectral lines and various visible spectrum of radiation, so the high-pressure sodium lamp light shade is greater than that of low pressure sodium lamp. High pressure sodium lamp is often a type of large intensity fuel discharge lamp. Because of the unfavorable resistance characteristics of fuel discharge lamps, in the event the lighting alone received the energy grid, the doing work state is unstable, with all the discharge method continues, it will bring about circuit latest rises indefinitely, till the final light or circuit elements and elements is flow burning high pressure sodium lamp along with other gas discharge bulb, get the job done is arc discharge state, V-I characteristic curve towards the adverse slope, i.e. lighting recent rise, plus the voltage utilized to a bulb dropped.

So that you can make certain the steady operation in the light bulb, a circuit have to be linked in series by using a circuit with no optimistic cease to stability the detrimental resistance. Resistors, capacitors, inductors, and so on., are willing to get limited to movement. Resistive ballast has the benefits of modest size, cost affordable, and high pressure sodium lamp supporting use will come about is hard to start off, function resistance generates a higher heat, have more substantial space for heat dissipation and consumption energy is extremely significant, it can make the circuit lighting efficiency decreased. It is generally employed in the DC circuit, using a hundred AC circuit inside the light of the phenomenon of obvious. Capacitive ballast while not as resistive ballast its consumption power, temperature rise is very low, from the very low frequency energy supply, charging the capacitor, pulse peak existing, result in great harm towards the electrode, lights flashing, have an effect on the services life on the lamp bulb; work in substantial frequency circuit, voltage fluctuation can reach the best state, become a great ballast.

Magnetic ballast loss is smaller, stable impedance, the impedance bacteria primality smaller deviation, prolonged support existence, secure lighting than resistive ballast fantastic, recent and high pressure sodium lamp supporting use of ballast are inductive ballast. Its disadvantages are higher than benzene and substantial rates. Furthermore, electronic ballast has begun to seem, at present the cost expensive, reliability will not be along with the high-voltage sodium lamp is matched, except for unique occasions, under ordinary situations are seldom utilized. For that reason, high pressure sodium lamp and lamp ballast series have to be corresponding specs just before use. High pressure sodium lamp lighting circuit can be a nonlinear circuit, the energy issue is very low, so in the network take into account a compensation capacitor is linked to enhance the energy aspect of the network