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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => AC Power and Grounding => Topic started by: David Allred on March 12, 2018, 08:15:52 PM
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I did a little research and just need a confirmation of my interpretation. I need to force cool down periods for a fog machine that on some days can be on for up to 12 hrs. 6 hour rated. Thinking about 3 on and 1 off. Anyway, the relay of the timer as 2 ratings. A higher resistive rating and a lower tungsten rating. A fog machine falls in the resistive category, correct?
Thanks.
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I did a little research and just need a confirmation of my interpretation. I need to force cool down periods for a fog machine that on some days can be on for up to 12 hrs. 6 hour rated. Thinking about 3 on and 1 off. Anyway, the relay of the timer as 2 ratings. A higher resistive rating and a lower tungsten rating. A fog machine falls in the resistive category, correct?
Thanks.
Mostly a toaster oven with some tubes. And a small ac pump.
So yeah, resistive; though I am unsure how tungsten is any less resistive than a resistor?
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though I am unsure how tungsten is any less resistive than a resistor?
A tungsten lamp has a high inrush current when it is first powered on.
The cold resistance is much lower than the operating resistance. The resistance of most materials goes up as they get hotter (like speaker voice coils), but it's particularly pronounced with tungsten light bulbs.
You can calculate what the operating resistance of a 100W lightbulb is (144 ohms), but if you measure a cold filament, it will be far less.
GTD
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A tungsten lamp has a high inrush current when it is first powered on.
The cold resistance is much lower than the operating resistance. The resistance of most materials goes up as they get hotter (like speaker voice coils), but it's particularly pronounced with tungsten light bulbs.
You can calculate what the operating resistance of a 100W lightbulb is (144 ohms), but if you measure a cold filament, it will be far less.
GTD
Ahh! Thanks for the explanation!