how do audio coils work?

[electricguru]

During my circuit scavaging I come across coils with 6-10 leads sticking out of them. I know that they are called audio coils but I wanted to understand how they work and what they are generally used for. I would appreciate any insights on this part.

Ω

 

[colin55]

Where did they come from?

 

[electricguru]

odd circuit boards I have salvaged ( umm... old power supplies, maybe large computer screens, and other unidentified circuit boards).

 

[Nigel Goodwin]

During my circuit scavaging I come across coils with 6-10 leads sticking out of them. I know that they are called audio coils but I wanted to understand how they work and what they are generally used for. I would appreciate any insights on this part.

I've never heard of anything called an 'audio coil'?, try posting a picture of one - click on 'Go Adnvanced' and then 'Manage Attachments' to upload it here.

 

[colin55]

odd circuit boards I have salvaged ( umm... old power supplies, maybe large computer screens, and other unidentified circuit boards).

These types of coils are not called "audio coils."
About the only type of coil you could call an "audio coil" is the crossover coil in a speaker network.

 

[electricguru]

I am very sorry. I belive they are called audio "trasformers".
Thanks!

**broken link removed**

 

[Shadowskater]

Transformer types - Wikipedia, the free encyclopedia

What do you plan on using them for?

 

[Nigel Goodwin]

I am very sorry. I belive they are called audio "trasformers".
Thanks!

**broken link removed**

You can get audio transformers, but they are pretty rare these days - that looks far more likely to be a switchmode power transformer, or a filter of some kind. Such devices are of very little use as they are so specialised.

 

[electricguru]

You can get audio transformers, but they are pretty rare these days - that looks far more likely to be a switchmode power transformer, or a filter of some kind. Such devices are of very little use as they are so specialised.

O.. ok. Well, I appreciate your answers and replies.

electricguru.

 

[BobW]

Audio transformers are not as common as they were back in the vacuum tube days, but they are still reasonably common for isolation and impedance matching.

They work the same way that other electrical transformers work, but "audio" tells you that they are designed for the audio frequency range, 50-20,000 Hz, rather than a power transformer which is designed for 50-60 Hz.
Transformer - Wikipedia, the free encyclopedia

 

[Nigel Goodwin]

Audio transformers are not as common as they were back in the vacuum tube days, but they are still reasonably common for isolation and impedance matching.

Hardly that, they are as rare as hens teeth

It's very,very rare to find audio transformers these days, you get a few microphone transformers, and in passive DI boxes, but most of those are active using opamps these days - transformers are just too expensive, and limit quality too much.

 

[canadaelk]

Nigel G:
In HiFi apps. transformers are mostly history (except for those tube enthusiasts)
But, in commercial sound, these things are totally indispensable. In a large office building with 5k loudspeakers for sound-masking you will find 5k transformers! I know some efforts were made to go active, but they fizzeled! Every school communication-system or office paging system has them. The death of the audio transformer has been greatly exaturated!
Altek, Lowell, Atlas, Midle Atlantic, Jensen, Rauland are just a few mfgs. who still make them in the US! And I could not immagine our phone (pots) or radio/TV to work without!
E

 

[audioguru]

The cheap little TY-145P transformer is 600 ohms CT to 600 ohms CT and was probably used in a telephone answering machine or in a dial-up modem. Its small size cuts low audio frequencies.