How transformers actually operate

In summary: Transformers require AC because passing AC through a coil creates a changing magnetic field around that coil. DC certainly does produce magnetic field, but it does not change with time. This is why transformers need to use AC. When an AC current is passed through one of the transformer's two coils (usually called the primary winding), its changing magnetic field also engulfs the other coil (usually called the secondary winding). The electrons in the secondary winding react to the changing magnetic field by continuously moving. (If you applied a DC current instead, the electrons in the secondary winding would only move for a split second, then settle down -- you'd get no continuous current.) This is how transformers allow the movement of electrical energy
  • #1
sp00ky
22
0
I was just wondering how transformers actually operates. And I hear they need to use alternating current and I was just wondering why they need to do so.
 
Physics news on Phys.org
  • #2
sp00ky said:
I was just wondering how transformers actually operates. And I hear they need to use alternating current and I was just wondering why they need to do so.
http://www.bbc.co.uk/schools/gcsebitesize/physics/electricity/electromagneticinductionrev4.shtml are large, ringed, pieces of metal that have two sets of coils around opposite sides. An AC current is used because this induces a magnetic field, that a DC does not. A different in the number of coils in the different sets means that the voltage changes from low to high or high to low (high and low not set values).

The Bob (2004 ©)
 
Last edited by a moderator:
  • #3
To clarify Bob's post a little:

Transformers require AC because passing AC through a coil creates a changing magnetic field around that coil. DC certainly does produce magnetic field, but it does not change with time.

When an AC current is passed through one of the transformer's two coils (usually called the primary winding), its changing magnetic field also engulfs the other coil (usually called the secondary winding). The electrons in the secondary winding react to the changing magnetic field by continuously moving. (If you applied a DC current instead, the electrons in the secondary winding would only move for a split second, then settle down -- you'd get no continuous current.)

In other words: a changing current in the primary winding induces a changing current in the secondary winding.

Transformers thus allow the movement of electrical energy from one wire to another, without the wires ever having to touch -- the energy moves from one wire to the other through the changing magnetic field. As The Bob says, the ratio of the number of turns on one coil to the other also determines the ratio of the potential differences (voltages) through the two coils.

- Warren
 
  • #4
okay...and is there only 2 types of transformers? A step up and a step down is basically the types of transformers there are right?
 
  • #5
sp00ky said:
okay...and is there only 2 types of transformers? A step up and a step down is basically the types of transformers there are right?
I can't see there being any others. You can step up the potential difference and step down the potential difference but what is the point in havong a transformer to keep the potential difference the same?

Chroot might say different and he will, therefore, be right but I think there can only be two.

The Bob (2004 ©)
 
  • #6
I know step-up transformers are used for tv's, pc monitors, and in many furnace-ignition circuits, but what types of stuff are used for step-down? I know some toys does but anythn' else?
 
  • #7
In order to minimize the energy loss, the transmition line from the power plant and you house operates at a very high voltage, Over 100kV is not uncommon... but your power outlet is 110V only... how do they do that? and why are they using A.C. (alternating current)?
 
  • #8
Added to vincentchan notes, what component is integrated in your charger when you want to charge your mobile phone sp00ky?
 

FAQ: How transformers actually operate

1. How do transformers work?

Transformers work by using electromagnetic induction to transfer electrical energy from one circuit to another. They consist of two or more coils of wire, known as the primary and secondary windings, which are wrapped around a core made of iron or other magnetic material. When an alternating current is passed through the primary winding, it creates a magnetic field that induces a corresponding alternating current in the secondary winding, thus transferring energy between the two circuits.

2. What is the purpose of a transformer?

The main purpose of a transformer is to step up or step down the voltage of an alternating current. This is necessary for efficient transmission of electrical energy over long distances, as higher voltages can travel further with less energy loss. Transformers are also used in electronic devices to convert voltage levels and provide isolation between circuits.

3. How does a transformer change the voltage?

A transformer changes the voltage by adjusting the number of turns in each winding. If the secondary winding has more turns than the primary winding, it will produce a higher voltage. Conversely, if the secondary winding has fewer turns, the voltage will be lower. The ratio of turns between the primary and secondary windings determines the voltage change.

4. Are transformers efficient?

Transformers can be highly efficient, with some models achieving efficiency rates of up to 99%. However, efficiency can vary depending on factors such as the design and quality of the transformer, the materials used, and the operating conditions. Transformers can also experience energy losses due to factors like heat and electrical resistance.

5. What are the different types of transformers?

There are several types of transformers, including step-up transformers, step-down transformers, isolation transformers, autotransformers, and pulse transformers. Step-up and step-down transformers are used for changing voltage levels, while isolation transformers provide electrical isolation between circuits. Autotransformers are used for voltage regulation, and pulse transformers are used in electronic circuits to transmit pulses of energy.

Similar threads

Time dependent canonical transformation
Replies
3
Views
1K
Classic Incline problem with cylinder
Replies
13
Views
491
Can Spacelike and Timelike Points Undergo the Same Transformations?
Replies
1
Views
653
Understanding Velocity Transformation
Replies
8
Views
1K
Connecting a step-up transformer backward
Replies
5
Views
1K
Applying Ampere's Law to a Transformer
Replies
5
Views
3K
Apply the Delta Wye Transform to a Circuit
Replies
13
Views
2K
Simplifying Complex Circuits: Using Delta to Y Transformation
Replies
3
Views
773
Confused by Lorentz transformation equation
2
Replies
36
Views
1K
Special relativity and standard configuration
2
Replies
40
Views
1K

Hot Threads

Recent Insights

Back
Top