Actually i wanted to know what type of tone would be available at pin 7. after constructed the circuit i gave tone o/p to input to the amp. but when i press the key it doesn't make any sense.. will it make sound if the circuit works?.. or let me know some ideas about that tone.. thanks..
Yes i gave the o/p of 7 to Hi-Fi system Aux input.. but doesn't make any sound..
So it needs to amplify, then only it makes sound right.. will try with oscilloscope..
Also gonna transmit tone via rf, should i have to amplify before give input to transmitter?.. thanks for reply..
yes sir i connected ground and 7th pin output to audio system say Left channel alone like mono input.. and then pressed the key.. i just tested encoder alone..
You left out some important parts.
Add R1,R2,C1,C2 you might have more luck. Plus replace your zener you've probably killed it. And you probably don't need the zener if you're using 5V
Pin 7 is open collector, you've got to add a pullup. It's all in the datasheet.
Thanks sir, And i am using another separate transmitter not mentioned in the above circuit. so i need to generate dtmf tone alone. still i have some confusion
because data sheet contains lots more connection..
If i have dtmf generator circuit alone it would be much better to experience with.. thanks.
Ok sir, can you tell me the value of pulldown resistor..
Shall i follow the circuit mentioned above to generate tone?
A small doubt, i am generating dtmf tone alone , is that R2 & C1 belongs to dtmf circuit or fm circuit.. thanks