19+ Dtmf Circuit Background. This dtmf decoder circuit recognizes the phone tone from the phone line and then decodes the pressed key on the keypad of the telephone. Circuit design of dtmf controlled home appliances:

Multiple Dtmf Circuits Able To Detect The Pressed Keys But Fails To Read Caller S Number Electrical Engineering Stack Exchange
Multiple Dtmf Circuits Able To Detect The Pressed Keys But Fails To Read Caller S Number Electrical Engineering Stack Exchange from i.stack.imgur.com
A couple of dtmf based fm remote control circuits can be seen in the following diagrams based on the proposed request. Dtmf decode circuit dtmf decode pcb. It presents a significant ac load on the line, attenuating speech by 70%, making conversations rather hard to hear;

Circuit design of dtmf controlled home appliances:

The power supply includes ic3, c6, c7 and c8 producing the +5v supply voltage for the circuit. A dtmf decoder attached with this circuit and this decoder is plugged into a mobile using an aux wire for receiving command or dtmf tone. A 9 volt battery is also used to power the motor driver for driving motors. Circuit design of dtmf controlled home appliances: