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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.
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:
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.