This diagram is the schematic diagram of telephone switcher using relays. This device connects to the telephone line and can be used to remotely control up to 4 relay outputs using a DTMF (tone dialing) telephone. A number of user settings are available to improve the useability and security of the device. The kit comes complete with a small plastic case with silk-screened front and rear panels.
The brain of this circuit is microcontroller chip Atmel MCS51 family AT89C2051. The source code is not available here, you may find out the source code by yourself.
The diagram is quite hard to designed in PCB, you may purchase the telephone switcher kits from this page: http://electronickits.com/kit/complete/tele/ck603.htm
The application notes for this circuit can be download here
This is the circuit diagram of power amplifier 45W using power uPC 1230 as the…
The Horn Circuit This is a basic circuit of car horn and lamp flasher that…
This is the circuit diagram of drinking water alarm based a small water sensor by…
Here is the 200W MOSFET amplifier powered based on four piece of IRFP250N, they are…
This is the 300W RMS stereo power amplifier circuit project. This amplifier is based four…
This is an active stereo tone control circuit using very well known op-amp IC of…