Model equations of fluorescent lamps were investigated as well on the high frequency operation. In the analysis of operating of the fluorescent lamp, the model equation of equivalent conductance of lamp on the high frequency is needed to performed. The model equations are estimated by the error-rate between the experimental waveform and the simulation waveform on the various operating frequecies. Any comparisons of differential model equations, model constants, and other components are discussed by relating characteristics of the fluorescent lamps on the high frequency operation. By using the delay time for the lamp voltage and lamp current, the error-rate values are improved. In each category of model equations, the most significant model equations are discussed. Some of the model equations are most suitable to simulate the characteristics of fluorescent lamp, therefore the ability of the model equations on the high frequency operation are increased.

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This paper is concerned with the investigation of the lamp current waveforms of the lead-peak type ballasts under the lamp operation. The hysteresis loop derived from the lamp current and the magnetic flux linkage in the secondary winding of the leakage transformer indicates the magnetic energy being stored in the magnetic field of the leakage transformer. And also, the area of its closed loop corresponds approximately to the energy consumed by the discharge lamp for one cycle. The figure of the hysteresis loop is related closely to the lamp current waveforms. The influence of the circuit parameters containing in the secondary circuit (or out-put circuit) of the leakage transformer upon the lamp current waveform can be discussed easily by use of this hysteresis loop.

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The cardiac interbeat interval sequences and respiratory movement curves have been measured for 30 minutes under the six illuminance of 100, 180, 320, 560, 1,000 and 1,800 lx. The light sources used were fluorescent lamps with a color temperature of 4200 K. The temperature in the test room was kept at 24 ± 1°C. Spectral analysis of the cardiac interval signal showed the presence of the vasomotor component centered at about 0.1 Hz. The mean heart rate, mean amplitude of the vasomotor component and the ratio of the power of the vasomotor component to the total power (without D.C. component) were calculated from the cardiac interval signals. The mean respiratory period and depth were obtained from the records of the respiratory movement curves. They were found to be significantly responsive to 1/4 log unit in illuminance. The results suggested that the physiological load was minimum in the illuminance range from 500 to 600 lx, and increased prominently with an increase in illuminance from this range, while it increased only moderately with a decrease in illuminance.

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An ordinary fluorescent lamp is essentially temperature dependent, so that the lamp luminous flux is greatly influenced by any change in temperature. This paper describes a fluorescent lamp lighting system operated by a variable high-frequency inverter using temperature-sensitive magnetic cores which compensate automatically for changing lamp characteristics. The temperature independent system having a fixed luminous flux can be utilized in the lighting industry, in plant growing and biotechnology and wherever an artificial light source in necessary.

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Additivity tests were carried out for a centrally-viewed 10° field using heterochromatic brightness matching at 6 retinal illuminance levels from 0.01 to 1000 photopic troland (Td). The results obtained by the mixture of 487 nm and 660 nm monochromatic stimuli showed two types of additivity failure. At the high levels of the retinal illuminance of 10,100 and 1000 Td, the brightness of the mixture was perceived to be lower than strict validity of the additivity law would predict. This is referred to as additivity failure of the reduction type. At the low levels of the retinal illuminances of 0.01 and 0.1 Td, the mixture appeared to be brighter than the brightness that the additivity law would predict. This phenomenon means additivity failure of the enhancement type. At the intermediate level of 1 Td, both types of additivity failure were seen. The type was determined by the luminance ratio of the two stimulus in the mixture. The results from another pair of mixtures, 463 nm and 567 nm, showed that additivity held at low levels, additivity failure of reduction type at intermediate level, and both types of additivity failure at high levels. The additivity failure observed at the mesopic levels are attributed to interaction between rod responses and responses from the red, green, and blue cones. These interactions are complex functions of luminance level.

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