Xenon vs. Discharge

[DanielArkley]

Having done shows on both Xenon Super Troupers and Robert Juliat Korrigan's, I was wondering what the differences between the two lamps were, other than the type. Obviously, one uses Xenon, and the other some other kind of discharge lamp.

 

Are the principals the same - throw an electric current through some gas?

Why do the Xenon's run at much higher temperatures, and wattage? - Is it simply because the Super Troupers are bigger, and need a bigger source?

Is one any more dangerous than the other?

 

Cheers!

Dan

[Brian]

Both are discharge lamps - a continuous spark inside a gas filled envelope. However, the main difference is that Xenon lamps require a DC supply whereas most other discharge lamps like HMI and MSR need an AC supply.

 

DC means that it does not flicker. Xenon lamps have a colour temperature of around 5600-6000K and approximate daylight very well. They have a very small arc which makes for good optical design and they are instant on with no warm up time. Oh and instant off and back on, no cooling required before restrike.

 

From a safety point Xenon lamps have a very high internal pressure, around 8 atmospheres when cold and 20 when hot.

[DanielArkley]

Any particular reason why the Xenon's use more power, or is it just because they are intended for use in bigger lanterns so to speak?

[Jivemaster]

Xenon is a good approximation to daylight but not as efficient as some of the odder coloured arcs. The sodium discharge is 170lumens per watt typ Tungsten lamp 12 l/w T/halogen 22 l/w, Xe about 40 some of the other arcs get to 70 l/w.

 

Who wants theatre lit by sodium yellow though, but it is good for street lighting!! high efficiency means low current draw.

 

Theatre is a trade between colour, brightness, power, and what's available anyway.