Hi i am doing DTMF project, i hav few old working Telephone sets.. i know it has both dtmf encoder & decoder.. without telephone lines i need to generate dtmf tones by giving external supplies , how its possible
Thanks
Hi i am doing DTMF project, i hav few old working Telephone sets.. i know it has both dtmf encoder & decoder.. without telephone lines i need to generate dtmf tones by giving external supplies , how its possible
Thanks
I have a problem interfacing my TP5088 dtmf generator and pic 16f84a to the telephone line as the audio transformer isnt available where i live so can i use anything else other than the transformer?????????????????
RAZ,
This is your third thread about your simple problem that I answered in one of your other threads.
Steal a transformer from an old telephone product or buy a new one from a large electronics parts distributor like Digikey.
yeah but i just mentioned that i cant find it in any telephone nor buy it as it isnt available in any electronics distributor in my city PLUS i noticed that modern integrated telephones dont use audio xfmr so i thought there must be a substitute for that xfmr !
try to purchase 1:1:1 pulse transformer. these are sold in market. they might work upto 5KHz
My city--- joke .
How do we know where you are?
see across names of Audioguru and mvs sarma clearly mention where we are !!
however check for part no RS Stock No.210-6324 of RS Components UK
Hey i managed to get the xfmr from an old telephone but its not 600 ohm its 200 : 160 and with centertaps . I found an interface ct. connecting 470 ohm along with the xfmr and the telephone that solved the power problem i had but the call still cant b place .The telephone line doesnt seem to recognize the generated tone and keeps giving me that tone that is waiting for you to dial :s:s what could b the problem ????