Audio transformer

thingmaker3

Joined May 16, 2005
5,083

Thread Starter

crivoli

Joined May 4, 2006
26
Originally posted by thingmaker3@May 6 2006, 07:45 PM
A 1:2 ratio will match 8Ω to 16Ω.

You will need 1:3 ratio to match 8Ω to 32Ω.

Do you have any additional data on the tranformer in question? The site provides nothing. (Typical of Radio Schmuck.) The transformer is likely not capable of what you want.

http://www.cpcares.com/xicon/Xicon_EI_19_A...mers/index.html

http://www.mouser.com/?Ne=100&handler=data...category&N=4204

Any chance of getting your money back from Radio Schmuck?
[post=16850]Quoted post[/post]​
Thanks for the response.

Here are the specs of the transformer I bought:

impedance: 1kHz, 1V, 0mADC
input: 1k ohm+- 10%
Output: 8 ohms (loaded)
DC resistance (input): 70 ohms +-20%
DC resistance (outout): .62 ohms +-20%
Frequency response: 300-10000Hz +- 3db
Insulation response: more than 100M ohms @250VDC


I looked at the links you provided but I don't know enough about the transformers to even pick one out to buy that would be a 1:3 ratio...... any suggestions on which to buy and how to tell the ratio?

Thanks again
-newb
 

Thread Starter

crivoli

Joined May 4, 2006
26
Originally posted by Papabravo@May 6 2006, 10:38 PM
Excuse me, but the ratio of 8 ohms to 32 ohms is actually 1:4 and not 1:3
[post=16857]Quoted post[/post]​
So, Papabravo.... can you suggest a transformer that is 1:4? Any specific brand or model you prefer?

Thanks
 

Papabravo

Joined Feb 24, 2006
21,225
Originally posted by crivoli@May 7 2006, 12:29 AM
So, Papabravo.... can you suggest a transformer that is 1:4? Any specific brand or model you prefer?

Thanks
[post=16861]Quoted post[/post]​
I've never had any occasion to use one so I'm in no position to make a recommendation. I suppose you could find a toroid and some magnet wire and make your own. Challenging, but not impossible. A company called Amidon makes toroids for RF applications; they just might have ones designed for audio.
 

legac

Joined May 4, 2005
54
A 1:2 ratio will match 8Ω to 16Ω.

[You will need 1:3 ratio to match 8Ω to 32Ω.]

Hi
Happy to say hello after long time away..

The formula to calculate IMPEDANCE should be
Z1/Z2= square of (N1/N2)- Turn ratio
Therefore 1:2 turn ratio match 8 ohm to 32 ohm
Re the Xformer mentioned above,
Z primary= 1K
Z sec= 8 ohm
You can load 8 ohm by 32 ohm. In such case the reflected Primary Impedace is 4K
(not 1K)
Cheers
 

thingmaker3

Joined May 16, 2005
5,083
Originally posted by Papabravo@May 6 2006, 08:38 PM
Excuse me, but the ratio of 8 ohms to 32 ohms is actually 1:4 and not 1:3
[post=16857]Quoted post[/post]​
Quite correct. One of these days I need to learn how to tpye.

Crivoli, is this for your intercom? If so, you'll need a trafo with an ouput impedence of 8Ω and an input impedence of somewhere between 25 and 120 Ω.
 
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