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TODAY
Battletoad


Registered: 09/25/03
Posts: 10,218
Loc: Metropolis City, USA
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Voltage and Amperes
#5941004 - 08/07/06 02:41 PM (17 years, 5 months ago) |
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Hey science guys, I was looking at HID lights on the net and was wondering, is there a tradeoff between volts and amps and useable power? Formulaically, there is no difference as Power = Volts x Amps but if that were the case, I might inquire about buying their 480 volt, 1000w light which would draw a little more than 2 amps. This instead of getting a 120 volt, 1000w light that would draw more than 8 amps. I think I'm running off 20 amps or whatever the standard but 2 of my 4 wall plugs don't work so I can't sacrifice blowing another one.
As voltage increases, does more power convert to heat and less made available for light or what?
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ca'rouse (k-rouz) intr.v. To engage in boisterous, drunken merrymaking.
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ZippoZ
Knomadic


Registered: 06/17/03
Posts: 13,227
Loc: Pongyang, North Korea
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Re: Voltage and Amperes [Re: TODAY]
#5941078 - 08/07/06 03:08 PM (17 years, 5 months ago) |
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i can tell you this, its cheaper to run a 1000w hps coming off of 240V than it is to do so off of 120v. so yes there is a trade off.
-------------------- PEACE
zippoz "in times of widespread chaos and confusion, it has been the duty of more advanced human beings - artists, scientists, clowns, and philosophers - to create order. In such times as ours however, when there is too much order, too much m management, too much programming and control, it becomes the duty of superior men and women and women to fling their favorite monkey wrenches into the machinery. To relieve the repression of the human spirit, they must sow doubt and disruption" "People do it every day, they talk to themselves ... they see themselves as they'd like to be, they don't have the courage you have, to just run with it."
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trendal
J♠


Registered: 04/17/01
Posts: 20,815
Loc: Ontario, Canada
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Re: Voltage and Amperes [Re: TODAY]
#5941158 - 08/07/06 03:34 PM (17 years, 5 months ago) |
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Good question!
As voltage increases, current draw decreases...but to get anything beyond 240v here in north america, you have to convert the power-line voltage to a higher voltage using a transformer. The transformer will waste some more energy so you'll have to facter it into account if you go beyond 240v.
Power consumptionp will stay relatively the same no matter what voltage/amperes you use - a 1000w bulb is going to consume around 1000w if it's powered by 480 or 120.
So costs-wise it doesn't matter a whole lot which you use.
However, in general, higher-voltage equipment costs more than lower-voltage equipment. A 480v ballast probably costs more than a 120 or 240 volt ballast.
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Once, men turned their thinking over to machines in the hope that this would set them free. But that only permitted other men with machines to enslave them.
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TODAY
Battletoad


Registered: 09/25/03
Posts: 10,218
Loc: Metropolis City, USA
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Re: Voltage and Amperes [Re: trendal]
#5941225 - 08/07/06 04:00 PM (17 years, 5 months ago) |
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Thanks to both of you.
As far as price of different voltage ballasts, I assume the 120v = 240v = 480v because they are marketed under one price (lets say $100) and it says: available in 120, 240, 480 volts. Now, this could mean that the transformerless ballasts cost $100 and they tack on the cost of the transformer if you order a light with a voltage that requires one, but I did not think about that, so I'm not sure.
So, as the transformer converts up to 240v to 480v, power is lost in the form of heat? This makes sense. So the higher voltage ballast will waste more power on heat...it'll actually consume more power than a 120v ballast to maintain the light output at 1000w? I would also take a guess that a ballast that runs hotter than another, all else being equal, wouldn't last as long so would have to be replaced sooner.
I'm not worried about a few cents extra or less of cost to run the thing, mostly just interested in not overloading the circuit and/or blowing my fuses.
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ca'rouse (k-rouz) intr.v. To engage in boisterous, drunken merrymaking.
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Seuss
Error: divide byzero


Registered: 04/27/01
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Re: Voltage and Amperes [Re: TODAY]
#5941317 - 08/07/06 04:28 PM (17 years, 5 months ago) |
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In general, the reason why higher voltages are more efficient is because power loss in a circuit is equal to the current squared times the resistance. (p=R*I^2) To gain efficiency, we want to reduce the current as much as possible. Since power is voltage times current (more or less), if we increase voltage, the we decrease current. By decreasing current we reduce the power loss due to resistance.
-------------------- Just another spore in the wind.
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TODAY
Battletoad


Registered: 09/25/03
Posts: 10,218
Loc: Metropolis City, USA
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Re: Voltage and Amperes [Re: Seuss]
#5941359 - 08/07/06 04:40 PM (17 years, 5 months ago) |
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That was the other piece I needed to hear. Heh, thanks Suess. I'm glad you smarties are so willing to help
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ca'rouse (k-rouz) intr.v. To engage in boisterous, drunken merrymaking.
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