Power Inverters

Loki7

Well-Known Member
It all matters on how much wattage the inverter draws compared to how much the lights draw if it's cheeper to go through the inverter then your saving. how much is the question.
The inverter will always draw more power than the lights and the lights will pull as much power as they are rated for...

If you give the converter 100 watts it can only output less than 100watts, because it wastes some power converting it. It can never give you more power than you give it...

-Loki
 

koolhand77

Well-Known Member
Alright this is how I see it. It's pretty simple unless I'm missing somthing.

This 120v converter draws 9.6 watts and it pushes out 15dc volts.

now if I power my inverter from this converter the most amount of wattage im drawing is 9.6 watts. Now from my inverter that turns 15dc volts to 120v with 2000 watts of power I will only be paying the electric company for the 9.6 watts used instead of the 400 it will take to power my lights. I might be way off at this point. But, I think is good.
 

Lipples

Well-Known Member
you are trying to make power dude. you can make your setup work, but it will NOT be saving you any energy.

Watt = volts x amps. Lets work through your problem backwards with a 1000watt light to make it easy.
v = volts
a = amps
w = watts

start with a 1000w light, that means that at 120v it is pulling 8.33 amps (120x8.3=1000)

Going backwards down the line the 120v needs to be converted to 12v BUT it needs to have the same total amount of energy running through it (1000w).
120v/10=12v
8.3a x 10 = 83.3a
12v x 83.3a = 999.6w (not perfect because of rounding)

That means that for 1000w of electricity to flow into the inverter @ 12v, it has to be pushed at about 83.3a. Going backwards even further, the 12v has to be converted back into 120v because thats what it is at the wall socket where the transformer does its work.
12v x 10 = 120v
83.3a/10 = 8.3a

That means that the draw at the wall is 120v @ 8.3a. THE SAME AS WITHOUT THIS SETUP.

I didn't even take into account the efficiency of the inverter and transformer. Both lose a LOT of energy in heat, so to get 120v @ 8.3 amps out of the inverter it would probably be pulling 120v @ 10a out of the wall, making your total power consumption 1200W instead of 1000W by just plugging the light into the wall.
 

Lipples

Well-Known Member
Alright this is how I see it. It's pretty simple unless I'm missing somthing.

This 120v converter draws 9.6 watts and it pushes out 15dc volts.

now if I power my inverter from this converter the most amount of wattage im drawing is 9.6 watts. Now from my inverter that turns 15dc volts to 120v with 2000 watts of power I will only be paying the electric company for the 9.6 watts used instead of the 400 it will take to power my lights. I might be way off at this point. But, I think is good.

you have 7 years of electrical apprentice history 0.o

Did you even look at the OTHER numbers on that transformer? It puts out 15dc volts....AT 400mA. That means its putting out hte 15v DC at less than HALF OF AN AMP. that means the total power it can put out is 6w of power. (15v x .4a). The inverter will only be getting 6w of power, and will only be able to convert the 6w of power. Yeah you can plug it into your inverter, then you will have 120v @ .05a coming out of it, when your light needs 8.3a to work.
 

koolhand77

Well-Known Member
it was genral electric work went to school for it. Droped out high school. I'm not that smart thats why I posted it. I cut grass now goes to show how smart i am right. So how much wattage does a car battery through out?
 

BigBudBalls

Well-Known Member
I did about 7 years as an apprentice. I really think this would work. I just don't know to much about the inverters. What r u running for lights and what not?
Yet you learned nothing.

Inverters are horrible inefficient, and usually produce a modified sine wave at best.

Not to mention just the basic law of diminishing returns proves this is busted.
(basic high school physics. Perpetual motion is impossible)
 
K

Keenly

Guest
this would not work....

as you transform the voltage out of the wall down... your only going to be able to get so much current up

since were using easy numbers, a 12v transformer would be a 10:1 step down

whats the current rating on it? because when you step the voltage back up, the current actually goes DOWN

you step voltage UP current goes DOWN

its going to be the exact same as just running 1000w out of the wall

the universe gives you nothing for free
 
K

Keenly

Guest
Alright this is how I see it. It's pretty simple unless I'm missing somthing.

This 120v converter draws 9.6 watts and it pushes out 15dc volts.

now if I power my inverter from this converter the most amount of wattage im drawing is 9.6 watts. Now from my inverter that turns 15dc volts to 120v with 2000 watts of power I will only be paying the electric company for the 9.6 watts used instead of the 400 it will take to power my lights. I might be way off at this point. But, I think is good.

this is where you are wrong... if you step this thing up your current will go down,

so 120v x 40 Ma

(you have stepped up the 12 back to 120 and the current goes down by the same ratio, which is ten to 1)

120v x 40 milliamps = 4.8 watts

that is me proving your idea wont work

not trying to be a dick but i want to tell you before you either hurt yourself with lack of electrical knowledge, or you get all this set up and realize it doesnt work

there you go

ALSO, one more thing

that transformer you have right there, that wall wart DC converter has a max output wattage of 6 watts

6w = 15v x .4A 15 volts times .4 amps = 6 watts MAX OUTPUT w/o it burning of course
 

koolhand77

Well-Known Member
We've already established that i was wrong. Your cuttinng grass is more fun I can smoke weed and cut grass. What I was assuming was that the transverter would produce the 1000 watts. I don't know why I was thinking this but, I was I am pot head. So I understand now that you need a power sorce with what ever amount of juice you need but, voltage doesn't matter because you can change that inverters converters and what not.

That's why I Posted this to get some answers because I wasen't clear on the whole thing. I didin't know somthing so i sought out the answer.
I can't thank you guys enough. all 4 guys who helped all got repped.
 
K

Keenly

Guest
this is how it all works

a transformer is 2 coils of wire seperated by a core

a 10:1 step down transformer would convert 120v AC to 12v DC via transformer and regulation

now, coil ONE on this trasformer (called the primary) should have 10x more turns than the secondary

the primary is what is connected into the wall, and this coil of wire now has 120v running through it (AC of course as transformers also DO NOT WORK WITH DC)


let me say that too right now

ONCE AC IS TRANSFORMED INTO DC IT WILL NOT WORK IN A TRANSFORMER

transforming requires RELATIVE MOTION in order for the electrons in the secondary

this relative motion is achieved in AC through the 60 Hertz up and down value of +120, -120 +120 -120

in DC, there is no motion, so if you try to connect even 1 million volts DC into a transformer, you will not get voltage out of the secondary

3 things depend on the voltage created

1. Strength of magnet (the current running into the primary wire creates a magnetic field, the stronger the current the stronger the magnet)

2. # of turns on the primary and secondary

3. SPEED OF RELATIVE MOTION - this is the part that kills you, since DC has no relative motion you just can transform it back up to 120v AC once its down to 12v DC
 

420weedman

Well-Known Member
We've already established that i was wrong. Your cuttinng grass is more fun I can smoke weed and cut grass. What I was assuming was that the transverter would produce the 1000 watts. I don't know why I was thinking this but, I was I am pot head. So I understand now that you need a power sorce with what ever amount of juice you need but, voltage doesn't matter because you can change that inverters converters and what not.

That's why I Posted this to get some answers because I wasen't clear on the whole thing. I didin't know somthing so i sought out the answer.
I can't thank you guys enough. all 4 guys who helped all got repped.

lol ... i think he just feels like explaining it all again to you.. donno whybongsmiliebongsmilie:bigjoint:
 

koolhand77

Well-Known Member
how the hell do you guys remmember all this shit. I have been out of school 15 years jesus now I'm sorry I brought it up.
 
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