Quartz halogen lamps have highly desirable properties for use in transient thermography including low cost, high power, and low weight. Those properties make them attractive for inexpensive portable systems. On the flip side, halogen lamps have slow turn-on and turn-off times, which can exceed the response time of the tested samples. Their slow response results in inefficient use of power. An additional problem is the large inrush current during turn-on. Considering the intermittent mode of operation – a few seconds on and then a few seconds off, this is a severe limitation. The inrush current can overload the power line and restrict available power. When using the newly introduced equivalent wave field thermography, it is important to know the exact heating profile of the lamp. Methods to extract this profile from the lamp parameters or the thermography data are presented. In this presentation I will introduce a lamp model based on the physics of the filament. The model has an analytical solution during the cooling phase and it was solved numerically during the active heating phase. The model compares very well with the measured data. Using the model, it is possible to analyze electronic lamp drivers and the lamp parameters and their effect on total system performance.
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