Working of Advanced Electric Ballast
A lot of power is lost in controlling the fluctuating current using resistors. For this reason, resistors are not used in applications having electrical load of more than 2 watts. Instead of resistors, a reactance is used. However, because of the losses due to the magnetic core inside them, a significant amount of energy is lost in both of them, and thus an inductor is used.
An inductor allows less energy loss and uses all the power saved in a more efficient manner. However, an inductor results in a current which is out of phase and has a poor power factor. The power factor is the measure of actual power divided by the apparent power. The more the power factor the more number of appliances can be used in the same circuit. To solve this problem, a capacitor is used along with the inductor to improve the power factor. The use of capacitor reduces the flicker of lamps, maintains a higher power factor, and balances phase relationships between all the lamps.
Also, if the lamps are large, higher voltage is required for the starting purpose and for this reason advanced electronic ballasts are used. In gas discharge lights, electronic ballasts maintain the starting and operating voltages and thus limit the flow of current through the equipment. Moreover, most of the modern electronic ballasts can operate lamps at higher frequencies as they use semi-conductor component circuitry rather than the conventional electro-magnetic transformer circuit. Also, as they use semi-conductor components, very less amount of heat is generated. Moreover, electronic ballasts operate at high frequency, which also increases the efficiency of the lamp.