EEFL Lamp / Inverter Specifications And Explanations

Explanation of Lamp Operation: There are two main factors limiting the life of fluorescent lamps and cold-cathode fluorescent lamps. The first is electrode (cathode) failure. The emission coating on the electrodes at each end of a linear fluorescent lamp deplete over time, which is the major cause of lamp failure and a barrier to longer lamp life.

The second main limiting factor to the life of fluorescent lamps and cold-cathode fluorescent lamps is that of leakage around the electrode wires that travel through the glass wall at the ends of the lamp. Fluorescent lamps are filled with noble gas, typically argon, perhaps krypton, and sometimes a little neon. When the seal around the electrode wire leaks, the gas mixture inside the lamps is contaminated and the lamp fails.

External electrode fluorescent lamps, as their name suggests, have no electrodes inside the lamps; with no electrodes inside the lamps, there is no need for electrode wires to pierce the glass at the ends of the lamps. Essentially, the EEFL is simply a sealed glass tube, with a phosphor coating inside. There can be no leakage and contamination of gas and there can be no cathode failure… the two leading causes of failure in fluorescent tubes. In EEFLs, the electrode is on the outside of the glass tube. This external electrode may be a metal cap around each end of the tube, the ends of the tube may be dipped in a metal solution and fired, or a conductive material may be fritted (fused) to the ends of the tubes.  
Inductively coupled electrodeless fluorescent lamps, such as EEFLs, may last as many as 100,000 hours, but typically have average lives in the 60,000 – 80,000 hour range.

Our EEFL Characteristics

1. Long lamp lifetime (no internal electrodes), 60,000 – 80,000 hours
2. 4mm diameter, 400mm – 1200mm length (8mm available)
3. Durable outside electrodes, no electrode burnout
4. Available in many color temperatures
5. One inverter drives many lamps
6. Higher efficiency (brightness per watt)
7. Lower power consumption
8. Low heat generation
9. May be bent or shaped

Bob Krohn, Visionary Lighting & Display’s President, has developed and patented the structural EEFL lightpanel, a light, rigid, tough polycarbonate (Lexan) panel which houses and protects the lamps. This technology has been licensed to Lighting Panels, LLC.

The polycarbonate lightpanel, along with specially-developed silicone lampholders, allows the manufacture of a complete, lightweight, long-life, ready-to-install backlight system.

EEFLs, for optimum life and output, like to operate at about 6.8 milliamps; which is a very small current… and at the proper voltage, which varies, depending on the lamp length, from 1,000 volts to 2,000 volts, typically at about 60,000 – 80,000 Hz. Available inverters have over-current, over-voltage and high temperature protection, they are rated at 50,000+ hours of operation, and, for a given size of lamp, can generally operate from two to ten lamps.

Ballast Characteristics:

Input voltage: 120VAC, 60 Hz (230VAC, 50Hz available)
Output Voltage: 1,000V – 2,200V
Output Frequency: Variable. 60,000Hz – 80,000Hz
Output Current: 6.5mA per lamp
Power Consumption: 20 watts – 55 watts, depending on the load
Number of Lamps Operating: Typically 2 - 10
Warranty: 3 years