IC &Audio transformer equivalent

Thread Starter


Joined Sep 1, 2005
Pls, I have got an intercom circuit from a site that uses MC145436 DTMF decoder but the IC is obsolete, how do I get the equivalent becos I've searched to no avail.

Also, I need a 1k/8R centre-tapped at 1K winding audio xformer for the ringer cct of d same project, I read that using a mains xfomer (for 12V operation, 60v centre-tapped secondary and 230v prmary), one could achieve the same, Is it possible/true?

Which scrap can I easily get audio transformer for me to use?

Pls, my project is being delayed due to these two problems.



Joined Sep 26, 2009
audio transformer can be found at Rat Shack (Radio Shack, you have questions, they have blank stares!) just picked one up a few weeks ago.....