Transformer question
Maz, Sat May 13 2006, 12:07AMSo i have always wondered how a transformer was made. then i looked in my textbook.
it says that is is just two coild around a laminated peice of iron to prevent eddy losses.
they dont have to be overlapping.
this suprised me, i always thought they worked by moving the electrons in the other wire because they were stacked on top of each other.
i guess im just looking for some feedback. who is right, and is it as easy as it seems to make?
Re: Transformer question
..., Sat May 13 2006, 01:16AM
The windings don't need to be wound on top of each other, they just both need to be on the same core. The iron carries the energy from the first winding to the second. In order for the transformer to work as a normal transformer you will need the iron core to make 1 or 2 complete boxes.
Yes they are pretty easy to make, but the tricky part is calculating how many turns to use to prevent saturation (when the core can't cary the energy--flux as we call it--between the windings) while minimising the losses encountered from using more turns (of a smaller wire).
..., Sat May 13 2006, 01:16AM
The windings don't need to be wound on top of each other, they just both need to be on the same core. The iron carries the energy from the first winding to the second. In order for the transformer to work as a normal transformer you will need the iron core to make 1 or 2 complete boxes.
Yes they are pretty easy to make, but the tricky part is calculating how many turns to use to prevent saturation (when the core can't cary the energy--flux as we call it--between the windings) while minimising the losses encountered from using more turns (of a smaller wire).
Re: Transformer question
Mike, Sat May 13 2006, 01:28AM
And to add on to what ... said, You really don't even need an Iron core. Take a Tesla Coil for example, it is air cored. In a really crappy explanation, the primary coil creates a magnetic field which is coupled to the secondary transfering the energy to it, The coils have no need to be on top of eachother for this energy transfer to take place. I guess you might get better efficiency if the coils are much closer together, but watch for arc overs if its high voltage/current.
Mike
Mike, Sat May 13 2006, 01:28AM
And to add on to what ... said, You really don't even need an Iron core. Take a Tesla Coil for example, it is air cored. In a really crappy explanation, the primary coil creates a magnetic field which is coupled to the secondary transfering the energy to it, The coils have no need to be on top of eachother for this energy transfer to take place. I guess you might get better efficiency if the coils are much closer together, but watch for arc overs if its high voltage/current.
Mike
Re: Transformer question
McFluffin, Sat May 13 2006, 01:56AM
While we are on the topic, what makes something a mains transformer? Gets saturated more easily so that it draws less power than another similar transformer would do(for example, a 120V to 60V transformer versus a 12V to 6V transformer)?
Not really a usual transformer, but piezo transformers are another odd type of transformer if you are not just necessarily looking at wire types. They use sound waves and piezo crystals.
McFluffin, Sat May 13 2006, 01:56AM
While we are on the topic, what makes something a mains transformer? Gets saturated more easily so that it draws less power than another similar transformer would do(for example, a 120V to 60V transformer versus a 12V to 6V transformer)?
Not really a usual transformer, but piezo transformers are another odd type of transformer if you are not just necessarily looking at wire types. They use sound waves and piezo crystals.
Re: Transformer question
Maz, Sat May 13 2006, 03:01AM
like if what you are saying plays true.
1 2
ol lo ol lo
ol lo ol lo
L____________l
it would look something like that
and if i wanted a step down say 120V to 12V i would have 10 on one but 1 on the other?
Maz, Sat May 13 2006, 03:01AM
like if what you are saying plays true.
1 2
ol lo ol lo
ol lo ol lo
L____________l
it would look something like that
and if i wanted a step down say 120V to 12V i would have 10 on one but 1 on the other?
Re: Transformer question
Self Defenestrate, Sat May 13 2006, 04:41AM
Turns depends on the size and VA of your core. Check the wiki, there should be something on it.
Self Defenestrate, Sat May 13 2006, 04:41AM
Turns depends on the size and VA of your core. Check the wiki, there should be something on it.
Re: Transformer question
ragnar, Sat May 13 2006, 08:09AM
Nobody seems to have explained well the principles behind a transformer here, yet :P...
I'm illiterate, but I'll try:
When you have an electrical current 'moving' through a wire, a magnetic field is produced around the wire.
When you have a CHANGING magnetic field and a wire present in it, an electrical current is induced in the wire.
Lenz's law states that when an 'electromotive force' (you can think of this as a current, since I've been wrongly using the word all along :P) is generated by a change of magnetic flux or field strength, the polarity of the emf will try to produce a current whose corresponding field would oppose the change.
In a conventional transformer, the iron core provides a permeable medium for the flux to travel in. When you wrap many turns of wire around the core, and run a CHANGING electrical current through it (e.g. 60Hz AC mains / sinewave), the domains in the iron carry the flux around the core.
In the case of the secondary, the wire on the iron core is wrapped around what is in effect a CHANGING magnetic field, and so an electrical current is induced into the copper wires.
Transformers don't (technically) work off DC, because the only change in magnetic field on the secondary occurs when you connect it to power.
Try this link:
You might search that site for a page on transformers - the hyperphysics site is a great resource for understanding/answering these kinds of questions.
ragnar, Sat May 13 2006, 08:09AM
Nobody seems to have explained well the principles behind a transformer here, yet :P...
I'm illiterate, but I'll try:
When you have an electrical current 'moving' through a wire, a magnetic field is produced around the wire.
When you have a CHANGING magnetic field and a wire present in it, an electrical current is induced in the wire.
Lenz's law states that when an 'electromotive force' (you can think of this as a current, since I've been wrongly using the word all along :P) is generated by a change of magnetic flux or field strength, the polarity of the emf will try to produce a current whose corresponding field would oppose the change.
In a conventional transformer, the iron core provides a permeable medium for the flux to travel in. When you wrap many turns of wire around the core, and run a CHANGING electrical current through it (e.g. 60Hz AC mains / sinewave), the domains in the iron carry the flux around the core.
In the case of the secondary, the wire on the iron core is wrapped around what is in effect a CHANGING magnetic field, and so an electrical current is induced into the copper wires.
Transformers don't (technically) work off DC, because the only change in magnetic field on the secondary occurs when you connect it to power.
Try this link:
You might search that site for a page on transformers - the hyperphysics site is a great resource for understanding/answering these kinds of questions.
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