I have been unable to build a transformer

[David lopez]

I have tried to build a transformer.
I have tried connecting a wien bridge oscillator to a wire. That wire
Formed 7 turns around a nail. A second wire was wrapped around the same nail it had 14 turns. The second wire was connected to a multimeter there was no voltage
Reading. The first wire was connected to second multimeter, there was current flowing through
The first wire. I think it was ac current. Any way to get this to work,
Without an electrical outlet.

 

[davenn]

Without an electrical outlet.

OMG, don't even consider putting this into a power outlet !

what frequency was the oscillator operating at ?
With the small number of turns you used, it's unlike that you would have measured anything

 

[David lopez]

Probably 1 hertz. Is that too low?

 

[berkeman]

Without an electrical outlet.

Please don't go anywhere near an AC Mains electrical outlet on your introductory electronics experiments. You can plug in pre-approved wall transformers and power bricks (look for the UL safety mark on them), but please do not consider trying to draw power from the outlets directly into your hand built circuits. Wait a few years and get experience under a Mentor who is in your area first. There are many safety design rules and tips that you need to learn first. Thanks.

 

[berkeman]

Probably 1 hertz. Is that too low?

Yes, way too low. Change the components in your oscillator circuit to output a frequency nearer 1kHz for now. You should start to see some coupling at that frequency.

After that, have you researched how to build a better DIY transformer compared to a nail? What issues/problems does a "nail transformer" have?

 

[David lopez]

So it won't work if the frequency is below 1 kilohertz?

 

[davenn]

So it won't work if the frequency is below 1 kilohertz?

Transformers will work below 1kHz, just not the way you have built your one

note @berkeman 's comments in his last post to you

After that, have you researched how to build a better DIY transformer compared to a nail? What issues/problems does a "nail transformer" have?

Go and do some googling and reading. Then come back with specific questions on anything you
read and didn't understand. Include links to what you have been reading so that we can
make sure you are on the right pathDave

 

[David lopez]

I have been using wire made of strands held together by colored
Insulation that I removed from microwave. It was not removed from a transformer. I should be using magnet
Wire? Why?

 

[berkeman]

I should be using magnet
Wire? Why?

For simple experiments, it doesn't matter much what kind of wire you use.

Magnet wire has thinner insulation than standard hookup wire. That is so you can pack more turns into the same winding "window area". The voltage between adjacent turns of transformer windings is usually pretty small, so you don't need a lot of insulation thickness to prevent arcing through it.

Does that make sense?

 

[Mark44]

I think it was ac current.

Probably 1 hertz. Is that too low?

Your transformer is not going to work on direct current (DC). What are you using for the input source to the primary windings? A battery will not work.

 

[David lopez]

Yes. And does it matter how much permeability the core has? Does a nail
Have too little permeability?

 

[davenn]

What are you using for the input source to the primary windings?

He said a Wien Bridge Osc

 

[Dadface]

David your transformer should have worked but with such low efficiency that the meter would not be sensitive enough to detect the very low secondary voltage induced. Look up transformer design.

 

[David lopez]

So how do I increase efficiency?

 

[anorlunda]

So how do I increase efficiency?

Good David. You are motivated to do it better. At this point, we are going to recommend that you put your effort into some study rather than asking questions on the Internet. That is a more effective learning strategy.

Here is a free web site:
https://www.electronics-tutorials.ws/transformer/transformer-construction.html

Here is a free book on the fundamentals
https://en.wikibooks.org/wiki/Electronics/Transformer_Design

If you start again after some study, please post here again on your results.

 

[Rive]

A nail is just no good for this. If you have an oscilloscope instead of a multimeter then you should be able to measure that - yep, it does something, but for this setup with a multimeter it is not adequate.

Try to increase the frequency into the 100Hz-1kHz range so you can hear it with some small speaker, then buy a ferrite core (maybe a big fat ferrite ring) and build a transformer onto that. With the speaker you should be able to check if it works, and then a multimeter should be fine for measurements.

 

[boB_K7IQ]

A single nail, although good for demonstrating a simple electromagnet is not a complete magnetic circuit. It has two open ends instead of a completed magnetic circuit and so what you have is an inductor rather than a transformer. It has a very wide magnetic gap which is good for storing energy but not for transferring energy from primary to secondary windings.

If you want to make a transformer out of iron nails, then you would need 4 nail arranged into a square, end to end which would complete the magnetic circuit and of course your winding of the wire around one or more of the nails.

Nails do not make good transformer magnetic material though unless the nails material alloy makeup are known to be good.

Driving a transformer with the proper frequency (I agree that 1 Hz is not going to work) and the oscillator will need to be able to supply the proper amount of magnetizing current for the nails and at that higher frequency.

I am guessing that a simple low current oscillator won't have enough current to drive a transformer and will just be shorted out but your nail transformer, especially at 1 Hz.

The links that were shown above are a good place to start looking. There are lots of resources out there and real transformer material is available depending on what you want to do with the transformer. The first thing you need to do is to be able to drive the transformer primary which is kind of what you are trying to do now without a secondary winding.

 

[StandardsGuy]

I have tried to build a transformer.
I have tried connecting a wien bridge oscillator to a wire. That wire
Formed 7 turns around a nail. A second wire was wrapped around the same nail it had 14 turns. The second wire was connected to a multimeter there was no voltage
Reading. The first wire was connected to second multimeter, there was current flowing through
The first wire. I think it was ac current. Any way to get this to work,
Without an electrical outlet.

As was mentioned, a nail is not an efficient material for a transformer. There are ferrite or powdered iron toroids that will work fine for frequencies at 1000 Hz (1kHz) up to several MHz. If you don't have one of them, then try an air core transformer made with a toilet paper roll or a wooden dowel or pvc pipe. You will need many turns, and may need a frequency of 1MHz or more to see it work. Your multimeter may not work at that frequency, but an oscilloscope probably will. Good luck.