Recent content by StillLearning

Thanks Ship, great references.

Thanks for your thoughts. I understand averages and curves, but at 90% of voltage or less these lights should be lasting over 7000 hours. We are getting nowhere near that. I'm trying to find the reason. Many of the bulbs are in a position where we need to rent a lift to change them. Real pain...

Thanks, Maybe time for more clarity. This is for a High School (read that, "No money unless you have a great reason and can wait a few years"). I am just trying to make the best of a bad situation. My plan is to convince the school to install some flourescents /HIDs in addition to the...

I guess I am still being too brief to be clear. We have an auditorium which is used for a lot of purposes besides performances. They use one or two presets for non-performance time, and the lights are set to that preset most of the day (12-16 hours) almost every school day. Some of the lights...

Thanks for the great info, but perhaps I did not explain my question well enough. The more you dim a standard incandescent light the longer it lasts. With halogen bulbs this is only true IF you keep the bulb hot enough to stay in the halogen cycle (about 250C). Once the bulb falls below...

Ushio notes that a halogen lamp cools below 250C the lifetime is significantly reduced. Their generalization is that 90% voltage is the lowest voltage suggested for halogen lamps. Lamp Life Calculator- Support Does anyone have info on how this affects HPL 575 is a Source Four Zoom? I would...

What more is there to say. Ive been in varius forms of electrical engineering for 30 years and am now learnign details about sound and light.