UV Ballasts
How Ballasts Work
UV lamps cannot be directly operated on 115 /230 AC power. Lamps have negative resistance, meaning that the lamp’s electrical resistance falls with rising lamp current. Without limiting the current, the lamp would burn out. The ballast’s primary function is to limit the lamp current to its rated value.
Ballasts incorporate a series of transistors, filter capacitors and electronics which allow it to take AC input and convert it to DC. This eliminates the effects of frequency variations.
Capacitors store energy and modulate the electrical output. The ballast then converts this DC back to AC and delivers this current back to the lamp.
Electronic ballasts are the standard drivers for low-pressure lamps. Lamp operation is flicker free and the ballast produces virtually no noise or hum.
The incoming 50/60 Hz power (110 or 230 volts) is converted to high-frequency AC (usually 20 to 40 kHz). This allows constant gas discharge and prevents cathode flicker. Electronic ballasts are efficient in converting input power to the proper lamp power.
The operation of UV-lamps at higher frequencies reduces end losses, resulting in an overall lamp-ballast system efficiency.
Low pressure standard and high output use similar technology to fluorescent lighting. The lighting and UV disinfection industries are similar in application environments. Systems are made for hot, cold moist and rough environments.
