PCB Heaven

General Category => Analog discussion => Topic started by: Keep_in_mind on April 05, 2008, 17:39:43 PM

Title: Interfacing a telephone line to PC
Post by: Keep_in_mind on April 05, 2008, 17:39:43 PM
How can i put the telephone line to the sound card of a computer (like the line in jack) and record the phone?
Title: Re: Interfacing a telephone line to PC
Post by: kam on April 06, 2008, 18:51:44 PM
Whatever you do, use also a 1:1 coil to save your card.
Title: Re: Interfacing a telephone line to PC
Post by: Alex on April 06, 2008, 23:05:58 PM
Check out the following diagram

(http://www.electronic-circuits-diagrams.com/telephonesimages/7.gif)

This is from smart Kit. Might help you.
Title: Re: Interfacing a telephone line to PC
Post by: methos on April 07, 2008, 18:55:41 PM
And add this 1:1 coil that Kam said before.
Title: Re: Interfacing a telephone line to PC
Post by: SiEger on April 10, 2008, 20:51:15 PM
And add this 1:1 coil that Kam said before.

Please what is this coil?
Title: Re: Interfacing a telephone line to PC
Post by: kam on April 11, 2008, 00:20:05 AM
This coil is a high frequency transformer. it will not allow DC current to pass and also the secondary coil has no galvanic connection with the first coil and thus it will prevent the PC to leak or get an current to or from the ground (earth)
Title: Re: Interfacing a telephone line to PC
Post by: Keep_in_mind on April 19, 2008, 12:48:31 PM
Thank you people!

Actually i found a ready construction for this. I believe is much more safer  ;)
Title: Re: Interfacing a telephone line to PC
Post by: methos on April 19, 2008, 18:43:18 PM
No it may not be.

I would 100% prefer something made by me. Because the ready one may be cheap because it (for example) does not have the 1:1 coil...