Efficiency

[Nab AC Analysis]

Is there any device in the world which have 100% Efficiency??

 

[Paul Obrien]

maybe? an ion particle drive, no I just figured out their efficiency, sorry.

 

[Nigel Goodwin]

Is there any device in the world which have 100% Efficiency??

No, and it's rather a silly question!.

 

[Dr.EM]

Just while were here, I have always wondered about electric kettles. Are they efficient? I mean, energy is usually wasted as heat, but the device is trying to produce heat so surely there is little "waste". The same applies to electric fires etc I guess, probably moreso. I can see that energy is lost in transfer to the water, but the heater itself (do heating elements light up inside like toaster wires?).

 

[Nab AC Analysis]

I think that stepup transform produce 100% efficiency its not a silly question though.... if you provide an input of 12 volts and try to get 220 volts stepup output... then according to Efficiency=Vout/ Vin x 100= 220/12= 100%
Now what to say??

 

[Roff]

I think that stepup transform produce 100% efficiency its not a silly question though.... if you provide an input of 12 volts and try to get 220 volts stepup output... then according to Efficiency=Vout/ Vin x 100= 220/12= 100%
Now what to say??

I say 220/12*100=1833%. Now what to say?
Efficiency, from a simplistic standpoint, is (power out)/(power in). You have neglected current in your equation.

 

[Nab AC Analysis]

I think all the transformer have their power factor which are reserved by the consumer point so it does'nt need any current in the equation??

 

[Papabravo]

If you already have all the answers, and have developed a perpetual motion machine in contradiction to the well known 2nd Law of Thermodyanics, why on Earth would you waste your time on this forum.

 

[Nigel Goodwin]

I think that stepup transform produce 100% efficiency its not a silly question though.... if you provide an input of 12 volts and try to get 220 volts stepup output... then according to Efficiency=Vout/ Vin x 100= 220/12= 100%
Now what to say??

I say your figures are completely wrong (and make no sense), 100% is PERFECTION, and nothing is perfect - which is why it's a silly question!. There will always be losses in whatever you do!.

 

[Roff]

What you think and reality are totally different. If you don't believe us, how about Wikipedia?
https://en.wikipedia.org/wiki/Efficiency
https://en.wikipedia.org/wiki/Electrical_efficiency
Note that Power=Volts*Amperes, where Amperes is the unit of current.

 

[akg]

Just while were here, I have always wondered about electric kettles. Are they efficient? I mean, energy is usually wasted as heat, but the device is trying to produce heat so surely there is little "waste". The same applies to electric fires etc I guess, probably moreso. I can see that energy is lost in transfer to the water, but the heater itself (do heating elements light up inside like toaster wires?).

sure.. we can contruct a kettle to have high efficiency , but not 100% -> which comes when the power o/p (used) == Input Power.
In case of kettle, losses are in form of conduction/convection/radiation

 

[Nab AC Analysis]

I would like to thanks all of you to participate on this silly discussion.... but its not silly in a way.... Nothing is perfect i believe that transformers cannot be the perfect device , they are not efficient as 80% ... as they have core lossses, winding and tap losses.... But the figures disagree with me....

 

[Nigel Goodwin]

I would like to thanks all of you to participate on this silly discussion.... but its not silly in a way.... Nothing is perfect i believe that transformers cannot be the perfect device , they are not efficient as 80% ... as they have core lossses, winding and tap losses.... But the figures disagree with me....

You haven't given any figures of any relevence, so they don't disagree at all.

Transformers are one of the most efficient devices you can get, more than 80% is quite possible.

 

[audioguru]

Simply plug in a mains transformer without a load. Then feel its heat a few hours later. Its losses are warming it which reduces its efficiency.

 

[dknguyen]

I was told transformers are the most efficient things made by people. And then for some reason the number 98% floats in my head. Of course, this was during high-school...and you never know the accuracy of their claims. I don't know if it's 90% or 95% or 98%. Never bothered to follow up...

 

[Hero999]

Depends on the transformer, a small 1VA transformer might only be 40% efficient, while a 10VA unit might give you 80% and a 1MVA 99%. Generally bigger transformers are more efficient than smaller ones and the same goes for motors.

 

[akg]

superconducting transformers will be much more efficient.

 

[Nigel Goodwin]

superconducting transformers will be much more efficient.

Except for the energy consumed keeping them at super low temperatures!, it rather ruins the efficiency figures

 

[Hero999]

Not if it's a really big transformer, using 500kW to supercool a 1GVA transformer is probably worth it, I've never heard of a transformer this big before though.

 

[Nigel Goodwin]

Not if it's a really big transformer, using 500kW to supercool a 1GVA transformer is probably worth it, I've never heard of a transformer this big before though.

That's assuming it would 'only' take 500kW to super cool it?, I suspect (in fact I'm absolutely positive!) you've got no more idea than me what it would take to supercool such a theoretical transformer