Transformer Questions!!! ???

[Tkjas]

Hi all,
I'm really confused about transformers, and have many questions  ???

Can u burn/break a transformer when u connect one end directly to a 9v DC battery?

How do u test a transformer?

I also have a transformer, it works in some projects but not in in other. One end, from the left most pin to the right most pin, it measures about 50Ohms. The other side measures only about .3 Ohms. I'm not sure if it's broken or not?

Can u also amplify an audio input with a transformer?

Also, what is the Watt rating of a transformer, and where can I find info about a transformer, since the one I have has no labels?


Thanks really much!!!

 

[audioguru2]

Can u burn/break a transformer when u connect one end directly to a 9v DC battery?

Yes. If the wire in the transformer is thin and is a low resistance, and the 9V battery is new. The new battery can have an output current of nearly 1A for a few seconds into a low resistance. That much current will cause thin wire to burn like a fuse. Transformers are used with AC, not DC.

How do u test a transformer?

Feed an AC signal on one winding and get the AC signal on other windings. The transformer might be designed to step-up or to step-down the AC voltage. You can use it backwards.

I also have a transformer, it works in some projects but not in in other. One end, from the left most pin to the right most pin, it measures about 50Ohms. The other side measures only about .3 Ohms. I'm not sure if it's broken or not?

It might be broken. Connect an audio oscillator to the 50 ohm winding and see if you get the signal from the 0.3 ohm winding. It will be much less.

Can u also amplify an audio input with a transformer?

You can transform, not amplify. The input power and output power of a transformer are nearly the same.
An amplifier increases the power of a signal by amplifying voltage andcurrent.
A transformer can increase AC voltage but since it cannot increase power then its current is less at the output. A transformer can increase AC current but then the voltage at the output is less.

Also, what is the Watt rating of a transformer, and where can I find info about a transformer, since the one I have has no labels?

Compare its size to a transformer that has a power rating.
Throw it away and buy a transformer with the ratings you need.

 

[Tkjas]

Thanks audioguru!!

Just a couple more

What's the point of having a transformer in a DC circuit?

Ever heard about making a transformer buzz? How would u cause a transformer to buzz?

 

[audioguru2]

What's the point of having a transformer in a DC circuit?

Which circuit?
Very old audio amplifiers and new PA amplifiers use an output transformer.
DC to AC inverters use an output transformer.
The high voltage circuit for a camera's flash uses a transformer.
Nearly everything electronic that is powered by the mains has a power transformer.

Ever heard about making a transformer buzz? How would u cause a transformer to buzz?

A transformer works with an AC magnetic field. Its core sometimes is laminations of steel that are insulated from each other and might be loose. Then they vibrate.
"Magneto-restriction" also causes a transformer to buzz.

 

[Tkjas]

would a buzzing transformer be a bad transformer, or it's ok to use?

 

[audioguru2]

would a buzzing transformer be a bad transformer, or it's ok to use?

An overloaded transformer could buzz and is dangerous.

A buzz noise from a normally operating transformer is an indication of poor quality. It might have other more serious and dangerous faults. Return it to the store for replacement or throw it away and replace it with a better one.

 

[MP1]

Tkjas,
You seem to have quite an interest in Transformers. Here is a link about winding transformers. It might have some information in it that will prove to be useful to you.

http://geek.scorpiorising.ca/windingtransformers.html

MP

 

[nanop]

Hi,

I've seen some of those transformers on neigborhood/city powerlines that has oil? inside of it. What would the oil be used for in the transformer?

Flouresent lights have transformers and most of them have a buzzing sound when it's turned on, or in my case, when the light's turned off for a while. Would the transformer be ok? Why does the buzzing happen for a while when the light's turned off?