Telephone Remote control Circuit not working - Electronic Circuits Projects Diagrams Free

MEHLULI · 8th April 2005, 02:25 PM

My circuit is not working, and I got it from Tripod. Instead of relays (mechanical) I am using opto-isolators. Also, I am looking for a circuit that I can use to test my MT7780 DTMF receiver to ensure that its working fine.
Please help!

panic mode · 8th April 2005, 04:45 PM

post your circuit

MEHLULI · 13th April 2005, 07:37 AM

Somehow there is an improvement. I couldn't sleep over the weekend until I could manage to get a signal through my DTMF receiver.

My problem now is, Can DTMF signal pass to my remote control receiver, more specifically the DTMF receiver (MT7780) connected in parallel to phone which is on-hook? My circuit is a slight modification of this one from:

http://electronicsworld.tripod.com/r...lsimages/2.gif

where I'm now using optocouplers and triacs instead of the relays here, and I discarded the Oscillator in my circuit.
So, my desire is to control my switching on of this remote control system, instead where I can make it automatically answer when it detects a ring (which will mean its now a dedicated line), coz I want to use the line for normal conversation at the same time should I want to, switch on appliances.

Thanx for atleast reading my problems

Chao!

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8th April 2005, 02:25 PM	(permalink)
MEHLULI	Telephone Remote control Circuit not working My circuit is not working, and I got it from Tripod. Instead of relays (mechanical) I am using opto-isolators. Also, I am looking for a circuit that I can use to test my MT7780 DTMF receiver to ensure that its working fine. Please help!

8th April 2005, 04:45 PM	(permalink)
panic mode	post your circuit

13th April 2005, 07:37 AM	(permalink)
MEHLULI	Circuit not working. Somehow there is an improvement. I couldn't sleep over the weekend until I could manage to get a signal through my DTMF receiver. My problem now is, Can DTMF signal pass to my remote control receiver, more specifically the DTMF receiver (MT7780) connected in parallel to phone which is on-hook? My circuit is a slight modification of this one from: http://electronicsworld.tripod.com/r...lsimages/2.gif where I'm now using optocouplers and triacs instead of the relays here, and I discarded the Oscillator in my circuit. So, my desire is to control my switching on of this remote control system, instead where I can make it automatically answer when it detects a ring (which will mean its now a dedicated line), coz I want to use the line for normal conversation at the same time should I want to, switch on appliances. Thanx for atleast reading my problems Chao!