Has anyone ever measured or happen to know what the operating temperature is for the FXL bulb (410w A/V Halogen used in many overhead projectors)?

Thanks!

My OHP conversion uses FXL bulbs. If you want, i can try to get a temp reading a few inches from the bulb. Just making sure you know, the FXL is an 82v bulb, and therefore requires some electronics (a beefy diode if i recall correctly) to run on 115v. My projection is nice, but with the reflector, don't expect to get a panel bigger than 12 or so inches with a 220 rear fresnel lens. Using a fresnel 300mm range you should be able to fit something the the 15.4 inch range into the light cone.

Just to let you know though, it gets hot. Really hot. The exhaust air is as toasty as a small hair dryer. I would not use without some serious thermal protection such as a hot mirror or some thick tempered glass.

Any temp measurements you can take would be great! And you are right, that thing runs hot man. This winter if I need a room heater I can just turn it on and let 'er run...

To keep my panel from melting I'm using an aggressive air cooling circuit with a 120mm fan and a pane of tempered glass.

Well, about 2" away from the lamp, directly in the beam of light, my cooking thermometer reads 180° F. Mind you thats with my case off and a 90mm fan right next to it. Also, the probe was polished stainless steel, so it may have reflected some IR (giving a lower temp reading than actual). If your trying to mount the lamp, i would suggest only aluminum/steel/ceramic. When these bulbs die, usually the quartz bubbles and cracks, not a filament failure. A quick google shows that quartz glass softens at 1,450°F!! So be careful and don't burn down your house...