It's a little after two in the morning. I'm at home. All is quiet.
And I can't sleep.
The longer I spend as a 'professional' lighting designer and programmer, the more I learn about myself. What I'm good at…and what I'm not. I spent an hour staring at the city-lit ceiling tonight with these ideas swirling through my head.
None of these ideas, mind you, should stand in the way of sleep. I've just finished one of my bigger shows for the year. Things are relatively peaceful and few deadlines are looming.
I guess I sleep better when I'm busy.
So, now I'm up. Not knowing what my brain wanted to be fed, I figured the least I could offer up to the small gods of sleep is a little tidbit for my three devoted readers.
Today's tidbit is a blasphemous re-write of the electrical formula of which I make the most practical use.
It's called (in blasphemer's terms) the West Virginia formula.
Simply stated, the formula is
W = V x A
Watts = Volts x Amps
WVA…West Virginia (If you haven't caught on yet, drop me a line.)
(The reason I speak so rudely about the naming of this formula is that few scientists or physicists would ever use those letters for the formula…thus destroying our pnemonic. In scientific formulas, the capital letter 'I' is used to represent amperage or flow. In the same way, the capital letter 'E' is used to represent voltage or pressure. Work or wattage is thus represented by the letter…well…'W'.)
The great thing about this formula is how easy it is to use and apply. Any time you know two of the three possible variables, I can always find out the third. Let's try it…
Example-
Let's say I have a conventional fixture with a lamp rated at 750 Watts. Assuming that I'm running it off a dimmer in the US, I can assume that the voltage is 120 volts.
With a little basic algebra, I can divide each side of the equation by 120, giving me…
A = 6.25
Thus, each fixture with this type of lamp can pull a maximum of 6.25 Amps at 120 volts.
Not too difficult, right?
I love to get feedback, so be sure to e-mail me at pgilbert@plsn.com with thoughts or suggestions.
PS – Be sure to check out Technopolis next month for the low-down and dirty on running your next big event using two tiny (but long) pieces of glass.
