I have a halogen light with a tungsten filament. It is rated 500w at 130v but I am running it from an inverter in my car that is putting out 110v. I would like to know what the actual power usage of this lamp is at 110v.
When I was a Sophomore in high school I had a physics lab where I calculated the temperature of a tungsten filament by measuring the current and then doing some calculation-which I can't pull out of my brain at the moment.
I am guessing that I am not the first person to do this and there must be some sort of curve that plots the current vs voltage of a halogen. If anyone knows of such a graph – or better yet some equations I could use to solve for an exact number, I would appreciate it.
EDIT: Ok, so I answered my original question, but if someone can give me actual equations instead of the mediocre graphs I found, I would be happy.
Best Answer
After posting this I poked around the internet and found a PDF all about halogens that included some graphs. None of the graphs were voltage vs current, but I did find a graph that was voltage vs flux, as well as power vs flux. Using those two graphs I was able to find that find the actual power of my light.
Here are the two graphs that I found. I drew some lines on them (the black lines) to help me find the values I was looking for because it was hard to read them. Using the data from these graphs, assuming it's accurate, my halogen is using about 88% of it's 500w rating which is 440w.