Edward E. Hammer

Characteristics of Various F40 Fluorescent Systems at 60 Hz and High Frequency

Recent improvements in both lamp and ballast technologies have resulted in substantial performance gains for fluorescent lighting systems. High-frequency electronic ballasts as well as high-efficiency 60-Hz electromagnetic ballasts have been designed to provide both better starting and operating conditions for the lamps under their control. At the same time, smaller diameter lamps and more efficient lamp phosphors have been developed to improve system performance further. How these improvements can be utilized in practical lighting systems is reviewed. Comparison characteristics, luminaire performance information, and application data are discussed.

Fluorescent Lamp Starting Voltage Relationships at 60 HZ and High Frequency

Starting voltage values have been measured with F40-type, rapid-start fluorescent lamps operating at 60 Hertz as well as at various high frequencies. The test circuits used as well as their suggested procedures are discussed along with the resultant data.

Effects of ambient temperature on the performance of bent tube fluorescent lamps

The effects of ambient temperature on the system performance characteristics of bent-tube fluorescent lamps for diameters ranging from T5 to T12 are discussed. Measurements were made from +40 degrees F to +120 degrees F ambient temperature with lamp currents ranging from 0.25 to 0.45 A. Results show that the light output and lamp efficacy peak at higher ambient temperatures for the smaller-diameter T5 biaxial lamp types as compared to the larger T8 and T12 diameter lamps. These data are important from a luminaire design standpoint because they indicate how the thermal characteristics of the fixture affect the system performance. It is concluded that be designing the luminaire geometry to give optimal bulb-wall temperatures improved system performance characteristics can be achieved. >

Starting voltage characteristics of 40 W biaxial fluorescent lamps

The starting voltage characteristics of 40 W biaxial fluorescent lamps were determined over an ambient temperature range of 0 degrees F to 90 degrees F using various starting aid distances and conditions. Results show excellent starting values with these lamps when used with 60 Hz electromagnetic ballasts designed specifically for such lamps. Further analysis of the results show that the limiting factor in the starting scenario depends on the ambient temperature and/or the starting aid distance. The database created would be an excellent starting place for the development of a generalized starting voltage equation which encompasses the variables tested.<<ETX>>

A New Optimized Fluorescent Lamp and Ballast for Low- Energy General Lighting Applications

A new fluorescent lamp and ballast system has been developed which minimizes system input power while maintaining light output close to values provided by conventional lamps and ballasts. The 28-WT-12 lamp designed for the new system utilizes a redesigned electrode structure which allows the lamp to be started in the rapid start manner but operated in an instant start mode to maximize the discharge efficacy (lumens/watt) while reducing lamp cathode power requirements. A matching two-lamp ballast incorporates a solid-state switching device to turn off the cathode heating circuit automatically once the lamps have started. Both lamps and ballasts are physically interchangeable with conventional equipment so that existing luminaires can be converted without luminaire, lampholder, and wiring modifications. This new lamp/ballast system can achieve efficacy values exceeding 80 Im/W¿more than 25 percent better than the performance of conventional fluorescent systems of the early 1970s¿along with the excellent life and reliability characteristics typical of electromagnetically ballasted systems. Economic analyses indicate that the new system is appropriate for many new commercial general lighting installations, although it is particularly suitable as a retrofit system for installations where power reductions are essential but where conversion costs must be minimized and illumination levels preserved.

Fluorescent System Performance of F40T12 and Smaller Lamp Diameters

Recent domestic and international developments with smaller diameter fluorescent lamps have prompted a review of lamp and system performance as a function of tube diameter. Limiting constraints on system performance when lamps of various diameter are used with the standard rapid start ballast are discussed. Performance comparisons are also made when these various diameter lamps are mated with ballasts optimized specifically for both 60 HZ and high frequency operation. The role of lumen maintenance in affecting the mean footcandle level throughout the lamp life is a key issue in these discussions.

New fixture applications for compact twin tube fluorescent lamps

Efficient luminaires have been designed for compact, twin-tube-type fluorescent lamps. One important example of their application is the 1-ft-by-1-ft luminaire with three 18 W, high-lumen, twin-tube fluorescent lamps. The performance of this luminaire type has been compared for different 18 W lamps operating on preheat and rapid-start-type ballasts. The preheat (switch start) measurements were made at 240 V and 50 Hz using single-lamp reactor-type ballasts, and the rapid-start measurements were made at 120 V and 60 Hz using three-lamp electromagnetic and electronic ballasts. In addition, comparisons are made against a 150 W incandescent downlight fixture with approximately the same light output level, indicating substantial improvement in system photometric performance for the new compact fluorescent light sources.<<ETX>>