Question about electricity

[Yoga Face]

When step up transformers increase the Voltage why is not that free energy?


I asked that question when touring the Niagara Falls electricity plant at Queenstown and the guide said they do it by increasing the amps as

Volts = amps * ohms

but that sounds like B S to me as the amps increase would be a result of the increase in Voltage not the other way around unless I am missing something conceptually about what electricity is

 

[red]

When step up transformers increase the Voltage why is not that free energy?

the voltage goes up but the current goes down- the energy is the same.


shocking, eh?

 

[Yoga Face]

the voltage goes up but the current goes down- the energy is the same.


shocking, eh?

But if the amps (current) goes down the voltage goes down as Voltage = amps *ohms but increasing or decreasing amps or ohms should not make any difference as the voltage always remains constant (in AC which is what we are discussing) if amps go down then the ohms (resistance) have gone up which is what caused the amps to go down


For example if the power line is cut the resistance to electric flow (ohms)becomes infinite which makes the amps zero as electricity stops flowing


The spinning turbine is creating the Voltage and decreasing, or increasing, the amps does not affect the turbine

 

[VIPhunter]

Power= IV....But, Power=I2R and V2/R........There is much more than Resistance in a AC Ckt. Impedence is definded as Z= R + (Xl- Xc)...There is an element called the trurns ratio in a transformer.......The impedence is more important than the pure resistance of the wire used.

By the way; The power is the same at the primary and secondary....as transformers are almost a perfect machine (very low loss).....But think of it this way....P=IV and P=2I *1/2 V OR better P= .....XI * V/X

 

[JohnHenry]

I think that what you are asking from your original post is the same question as why cars do not have higher overall gearing to increase speed without increasing engine rpm. Simple answer, the engine (water fall) doesn't produce enough torque to turn the turbine at the higher voltage.

 

[NYguardianangel]

Turbines have losses too; Transformers have losses, Long Circuits have losses. There are a few other things at play here to; Reactance (Impedence), Capacitance, and of course Resistance, or line loss; It would take days/months to explain these factors but, since we don't have that much time... here is the simple overview. When power is produced either by water, wind Fusion or Fission, there will always be a loss created by resistance - this is something that OHM's Law helped explain. but what most people don't understand this that to transmit power over long sections or copper there are more losses than just Impedence (Reactance). Reactance creates voltage drop over large transmission lines; so a 500,000 volt (actually 550K) line that comes from Darlington#1 that pushes to say Ottawa will have a voltage drop of .5v/m (estimated) by the time it reaches Ottawa that line needs voltage support because its down to 430K (its supported allow the way because a large drop is unacceptable to the grid and its also based on load factors in summer and winter). the only way to support the voltage is with capacitance (large Capacitors) these create something called VARS (did I lose you)?... VARS actually increase the voltage without changing the Current (AMPS) but they create great amounts of heat, - That's another story...

Simple put it's not a simple as Ohm's law or a Power factor; it takes time to understand the power grid, - Making/breaking parallels; Capacitance, Transformer Loss, Generators used as Spinning reserve for voltage support, Turbines that are Self-Excited; you would think they could produce their own sustaining power.

The only way that I can suggest you try to understand large power integration is talk to a power systems operator, buy him/her a coffee and sit back and be gobbsmacked... Just my opinion. Creating small simple sustainable power is easy, but when you look at large generators Like Beck1 and Beck2, Saunders, Darlington, Pickering, there's a little more than meets the eye.

 

[David007]

When step up transformers increase the Voltage why is not that free energy?


I asked that question when touring the Niagara Falls electricity plant at Queenstown and the guide said they do it by increasing the amps as

Volts = amps * ohms

but that sounds like B S to me as the amps increase would be a result of the increase in Voltage not the other way around unless I am missing something conceptually about what electricity is

You are correct. If the tour guide said "by increasing the amps" then that was a wrong answer. It is the transformer turns ratio that determines the output voltage. The load (impedance) will determine the current, subject to the limit of wire and core size. But I should add, there is no free lunch in terms of energy. There will in fact be some energy lost and dissipated as heat.

 

[Yoga Face]

I think you are making this too complex

A transformer is a device that transfers electrical energy from one coil to another

It does this by the coil that is charged (primary) creating a magnetic field that constantly varies in strength (because AC is created by positive then negative magnets inducing voltage as electricity creates magnetism and vice versa) through the secondary coil. This varying magnetic field induces a voltage in the secondary coil. This effect is called inductive coupling.

The number of windings in the secondary coil decides how stepped up (or down) the voltage will be


By merely adding windings you increase voltage

Is this not free energy?

 

[james t kirk]

There is no such thing as free energy.

Energy is constant and it is simply moved from one side of the equation to the other.

You can increase and decrease voltage with a transformer, however, power in watts remains equivalent to the energy input into the system in the first place.

Losses (as stated above) must also be factored into the equation. I can imagine some pretty wild multivariable calculus there and since it's been 20 years since I did any of that, I won't pretend to be able to explain how that might come into play.

 

[David007]

The number of windings in the secondary coil decides how stepped up (or down) the voltage will be

Correct.

By merely adding windings you increase voltage

Is this not free energy?

Voltage does increase, but the Power output = Power input - transformer loss. Sorry, no free lunch.

 

[Yoga Face]

You can increase and decrease voltage with a transformer, however, power in watts remains equivalent to the energy input into the system in the first place.
.

Watts= Volts *Amps

You are saying the watts remain the same therefore by increasing the volts you have decreased the amps(electrical flow)

conceptually i do not understand how an increase in voltage can decrease amps as amps is regulated by OHMS (resistance to electrical flow) in the circuit

 

[Yoga Face]

Correct.



Voltage does increase, but the Power output = Power input - transformer loss. Sorry, no free lunch.

I know there is no free lunch so I am missing something conceptually here

What do you mean by power?

Volts or watts ?

 

[IM469]

There is no such thing as free energy.

Energy is constant and it is simply moved from one side of the equation to the other.

You can increase and decrease voltage with a transformer, however, power in watts remains equivalent to the energy input into the system in the first place.

James has hit the nail on the head. In a transformer power (watts) is the same on both sides of the (perfect) transformer and since Power = Volts * Amps

Volts * Amps => Volts * Amps where '=>' is the transformer.

Lets look at 100 Watts in the form of 100 Volts / 1 Amp and we double the output voltage 100V* 1 Amp => 200V * 0.5 Amps Equal Power both sides.

Now lets go way higher in voltage - lets go up by 25,000 times 100V*1 Amp => 250,000V*0.000040A (40 micro Amps)

The reason this is useful is that transmission wires have resistance and you will loose energy resulting in a voltage drop over the transmission line.

Lets assume the transmission line to a Toronto from Niagara Falls has 10 ohms resistance. The voltage drop from ohms law is V=IR (Volts= Amps*Ohms)

Voltage drop to Toronto at 100 Volts * 1 Amp is 1 A * 10 Ohms= 10 Volts thus the voltage left in Toronto is 90 volts - the Power in Toronto is 90Volts*1Amp = 90 Watts

Our high voltage voltage drop is 0.000040 Amps * 10 Ohms = 0.0004 Volts thus the voltage is 249,999.9996 volts left in Toronto.

Put it into another transformer to bring it down and you virtually have all the power you started with. That is why power lines run at such high voltages and why Tesla (AC) not Edison (DC) won the power race. [Transformers only work with AC]

 

[LIM]

I know there is no free lunch so I am missing something conceptually here

What do you mean by power?

Volts or watts ?

You are right that people are making this more complicated than need be.

Power is measured in Watts and is useable energy no different than heat (btu's) or light (lumens) or even calories and can even be converted from one of these measurements to another.
Voltage is measured in Volts and is the electrical "pressure" and can also be referred to as electrical "potential"
Current is measured in Amps and is the electrical "flow"
Resistance is measured in Ohms and is the electrical "opposition" or "restriction" to flow

The reason induced voltage is not simply "free energy" is because the resistance values will not change regardless of if it is step up or step down. Because the resistance values will stay the same, the power values will also stay the same. Another way to say it is the voltage may be higher in a step up but the result will be current will decrease because resistance doesn't change. That is why some were showing the formulas.

Eg. If the resistance value of the whole system is 35k ohms and the voltage produced is 10k volts you will have a current of 3.5 amps. If you were to now insert a (let's say 1:2 ratio) step up transformer into the circuit, your induced voltage will become 20k volts. But a transformer doesn't change the resistance of the whole system (in theory) so you still have 35k ohms resistance which will now result in a current of 1.75 amps. So to figure out the actual useable energy (watts) you multiply volts by amps.
No transformer: 10000 x 3.5 = 35000 or 35k watts
With transformer: 20000 x 1.75 = 35000
So now you can see that even though the voltage is stepped up, the useable energy is constant as many of the previous posters also said.

Volts = amps x ohms; Watts = amps x volts

Clear?

 

[VIPhunter]

Or pehaps better: 100 Watts (power) is 100 watts. And if, for example it is delivered at 50V @ 2 A or 100 V @ 1 A or 5V at 20 A...if this power was consumed by an element specific to the voltage rating, that raised the temperature of a pan of water, the water would heat the same way.....Power delivered is the same.
Now, not to get all nit-picking...but power of a Transformer is stated in VA...not Watts, as the transformer is mearly transfering power...not consuming it.

 

[FAST]

Constant

VOLTS is not power, power is a product of volts AND amps.

Same thing with a motor,...horse power = RPM X torque/5252.

If you change one term, increase RPM for example, the other term ...torque has to be changed/REDUCED also, to keep the HP/power rating of a motor as a constant, like a transformers VA/power rating, which is a fixed unless you make it bigger/higher VA.

FAST

 

[toughb]

Well there we go. And I thought this might be complicated.

 

[NYguardianangel]

it does... we just use bigger wires and more POWER

 

[Yoga Face]

You are right that people are making this more complicated than need be.

Power is measured in Watts and is useable energy no different than heat (btu's) or light (lumens) or even calories and can even be converted from one of these measurements to another.
Voltage is measured in Volts and is the electrical "pressure" and can also be referred to as electrical "potential"
Current is measured in Amps and is the electrical "flow"
Resistance is measured in Ohms and is the electrical "opposition" or "restriction" to flow

The reason induced voltage is not simply "free energy" is because the resistance values will not change regardless of if it is step up or step down. Because the resistance values will stay the same, the power values will also stay the same. Another way to say it is the voltage may be higher in a step up but the result will be current will decrease because resistance doesn't change. That is why some were showing the formulas.

Eg. If the resistance value of the whole system is 35k ohms and the voltage produced is 10k volts you will have a current of 3.5 amps. If you were to now insert a (let's say 1:2 ratio) step up transformer into the circuit, your induced voltage will become 20k volts. But a transformer doesn't change the resistance of the whole system (in theory) so you still have 35k ohms resistance which will now result in a current of 1.75 amps. So to figure out the actual useable energy (watts) you multiply volts by amps.
No transformer: 10000 x 3.5 = 35000 or 35k watts
With transformer: 20000 x 1.75 = 35000
So now you can see that even though the voltage is stepped up, the useable energy is constant as many of the previous posters also said.

Volts = amps x ohms; Watts = amps x volts

Clear?

not clear

if you start with 10v and 2 ohms you start with

10v=5amps*2ohms

Step up the voltage to 20v then you have

20v=10amps*2ohms

you have the amps decreasing somehow

 

[Yoga Face]

[Transformers only work with AC]

transformers work with DC if you alter the voltage in intervals which can be done

It is this alteration that causes magnetic flux