telephone remote control -help!! - Electronic Circuits Projects Diagrams Free

theEgO · 1st March 2004, 03:58 PM

hello..
im having problems with my telephone remote control project. my project is basically the same as the one in this site :
http://electronicsworld.tripod.com/r...trolsckt2.html

ive constructed the circuit exactly like the one here. i have'nt assemble the relay parts yet bcoz i wanted to make sure the dtmf decoder n the few main ics are working. first i proceed to check for the required output frm the decoder by using the input frm the telephone line paralel to the telephone instrument. i tried to press for diffrnt keys to get the desired output but unfortunately all attempts have been a failure so far.
i am in a despair right now because i dont know wat izzit tat is wrong. im sure the circuits are connected properly. even my lecturer is not sure wat the problem is.
can some1 shed som light on me???
thank you vr much..

Sebi · 2nd March 2004, 06:44 AM

I don't see any problem with circuit diagram (except pin10: this input have internal pull-up resistor, so no need connecting to +). Check the X-tal oscillator and input signal level.

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1st March 2004, 03:58 PM	(permalink)
theEgO	telephone remote control -help!! hello.. im having problems with my telephone remote control project. my project is basically the same as the one in this site : http://electronicsworld.tripod.com/r...trolsckt2.html ive constructed the circuit exactly like the one here. i have'nt assemble the relay parts yet bcoz i wanted to make sure the dtmf decoder n the few main ics are working. first i proceed to check for the required output frm the decoder by using the input frm the telephone line paralel to the telephone instrument. i tried to press for diffrnt keys to get the desired output but unfortunately all attempts have been a failure so far. i am in a despair right now because i dont know wat izzit tat is wrong. im sure the circuits are connected properly. even my lecturer is not sure wat the problem is. can some1 shed som light on me??? thank you vr much..

2nd March 2004, 06:44 AM	(permalink)
Sebi	I don't see any problem with circuit diagram (except pin10: this input have internal pull-up resistor, so no need connecting to +). Check the X-tal oscillator and input signal level.