Beginner direction to transformers design and build

[tomerttb]

Hello everyone

I need some help on how to start with building my own transformers.
My current main goal will be to learn and build a transformer for ribbon mics.

I am looking for specific direction and tips about the following subjects:

1) Basic and important calculations for Ribbon mic transformers design, I do not want to dive over my head to math and theoretical calculations.
2) What electric equipment will I need in order to do measurements
3) What items i will have to purchase in need to experiment an build my own transformer.

Any help will be appreciated.
Thank you very much,
Tom

 

[ruffrecords]

When you say a ribbon mic transformer, do you mean the transformer inside a ribbon mic. These are rather specialised and often use non-standard parts. Or do you mean a transformer external to an existing ribbon mic?

Cheers

Ian

 

[tomerttb]

Hello Ian,

Thank you for your reply.
I am referring to the internal transformer found in ribbon mics.

Tom

 

[merlin]

Some cursory info:
http://www.diyaudiocomponents.com/diy-ribbon-mic-operation-principles

 

[abbey road d enfer]

My current main goal will be to learn and build a transformer for ribbon mics.

You haven't chosen the easiest and most academic subject for playing with xfmrs.

1) Basic and important calculations for Ribbon mic transformers design, I do not want to dive over my head to math and theoretical calculations.

Theory and math is a necessary evil when trying to understand things. You have to accept that some is needed. However, ribbon mic xfmrs are the result of several constraints that are not found on other xfmrs. That is due to the rather poor efficiency of the ribbon system and the constraints placed on connections. Most xfmr handbooks ignore these aspects.

2) What electric equipment will I need in order to do measurements

You need a signal generator with a very low output impedance (less than 0.05 ohm) and a millivotmeter. The former is generally not available; you need to combine a standard signal generator and a small power amp. Actually, the most important factor is measurement skills.

 

[tomerttb]

Some cursory info:
http://www.diyaudiocomponents.com/diy-ribbon-mic-operation-principles

Thank you for the link Merlin.

I read all the great information available on this site.

Tom

 

[tomerttb]

Hello abbey road d enfer,

Thank you for your help and info.

1) Can you suggest a reading source with valuable info for  ribbon transformers ?
2) I have an electronic lab, i checked the bench multimeter and he can measure from 600mv, is that sufficient ?
3) For the signal generator the specifications says "Impedance 50ohm", that's far away from what you suggested, I also checked several other devices i don't see anything close to 0.05 ?

Thank you very much for the information!
Tom

 

[abbey road d enfer]

1) Can you suggest a reading source with valuable info for  ribbon transformers ?

You may read about ribbon mics; the subject will likely be discussed, but designers tend to be secretive about what took them years and years of hard work to grab.

2) I have an electronic lab, i checked the bench multimeter and he can measure from 600mv, is that sufficient ?

No, when I wrote millivoltmeter, I meant it; you need something that's capable of measuring about 50mV with decent accuracy and a frequency response that matches the audio range. Multimeters usually have a poor frequency response above 1kHz.

3) For the signal generator the specifications says "Impedance 50ohm", that's far away from what you suggested,

That's quite typical. That's why I suggested the use of a suitable low-power amp designed to drive such a low impedance. It's not that hard to do, but again you need some theory and a little math.

 

[tomerttb]

Thank you all for your help!

Tom