Here is the circuit diagram of remote controlled appliance switch circuit. The main parts of this circuit are IC1 (NE 555), IC2 (CD 4017), IC3 (TSOP 1738), Q1 (BC 158) and Q2 (SL 100). This device can switch on/off any appliance connected to it using a TV remote.
Here the IR remote sensor is TSOP 1738 whose output is high when no signal is falling on it and becomes high if 38 KHz signal from TV remote falls on it. When the output of IR sensor becomes low, that will turn transistor Q1 into conducting state. Its low output triggers IC1 which is wired as monostable multivibrator and it produces 4 sec long high signals at its out put. This signal is given as clock to IC2 which is a flip-flop having two output pins (2 and 3). Then pin3 goes low and pin2 goes high. The output of pin2 is used to drive the relay through transistor Q2. The output of IC2 toggles when the next signal comes. As a result of this on each press of remote, the relay will be toggled and hence the appliances connected to it can be switched on/off by remote.
- Use a good quality PCB or common board to assemble this circuit.
- Use TV remote having a frequency of 38 KHz.
- The appliance can be connected through NO or NC and C contacts of the relay.
- Use a 6 V DC regulated supply for powering this circuit.