Use of trig in lighting design

[tgates]

3) In the US, two phase power is still in use (in a form). Most homes are wired with a type of two phase power. The transformer on the street has two hot legs from a 220v 3 phase system come in, the transformer has a center tapped secondary winding, creating a neutral. The center tapped neutral provides 120v between either hot leg and ground. The hot legs in this system are still 120˚ out of phase with eachother.

The power in homes is still considered "single phase" power, despite being two legs that are oppsate (180 degrees out) of each other.

Two phase power is a whole different beast, and is non-existent for power distribution, though most stepper motors still use a sort of two phase power. If you split these phases like you do with domestic single phase, you could have four different waveforms.

Three phase power can be split into 6 separate phases, which they used to use in old mercury arc rectifiers.

The wikipedia entry seems to agree with the other information I've read on two phase: http://en.wikipedia.org/wiki/Two_phase

 

[derekleffew]

I honestly have no clue, I just kind of reasoned it out, and I don't have a graphing calc with me to try to figure it out right now...

You almost got me! You're typing on a computer and saying you can't solve the problem because you don't have a graphing calculator? Do it old skool, in crayon on the back of a paper grocery sack. Or borrow STEVETERRY's slide rule.

 

[superdoo]

I could be mistaken here but, if the wave forms 120 degrees apart and the sine of 120 is .866 then you simply multiply .866 by 240 (your total voltage peak) and you arrive at the answer of 208V

Here is a source: http://en.wikipedia.org/wiki/Three_phase

And NO that does not require a graphing calc.

 

[nrcafootball68]

I could be mistaken here but, if the wave forms 120 degrees apart and the sine of 120 is .866 then you simply multiply .866 by 240 (your total voltage peak) and you arrive at the answer of 208V
Here is a source: http://en.wikipedia.org/wiki/Three_phase
And NO that does not require a graphing calc.

Yeah... I realized that was why as I was sitting in class today...

 

[TimMiller]

i am taking a class in AC circuits and they didnt tell me that you needed to know trig (its not on the prerequeset list). I wish i had taken it now. Talk about nothing but trig. Look into some RC circuits and you will be flooded with trig. I'm in the process of designing a square wave to sine wave converter just to see if i can do it without blowing something up . I love playing with things. (I love multisim, if it doesnt blow up on there, it probably wont blow up on the workbench but there is only one way to find out )

 

[superdoo]

Yeah I'm about to get my A.A.S. in electronics tech. I thank god they made me take trig before throwing me to wolves. All AC and wave analysis is trig. Let me know if you need any help designing that wave shaper.

And YES multisim is very nice, but I gotta say blowin up parts on a proto board is fun too!

 

[tgates]

i am taking a class in AC circuits and they didnt tell me that you needed to know trig (its not on the prerequeset list). I wish i had taken it now. Talk about nothing but trig. Look into some RC circuits and you will be flooded with trig. I'm in the process of designing a square wave to sine wave converter just to see if i can do it without blowing something up . I love playing with things. (I love multisim, if it doesnt blow up on there, it probably wont blow up on the workbench but there is only one way to find out )

Here's the thing, you have to be good at trig to doing the SIMPLE stuff. Any sufficiently advanced course in electrical engineering will require understanding of advanced math. I was originally a EE major, but ended up changing because despite completing several years of calculus, I still couldn't keep up with the math in the INTRO course. Stuff like three dimensional differential equitations with imaginary numbers, whee!