To turn ON/OFF home appliances, we can use IR remote control system switch with any IR enabled remotes. The TSOP1738 IR Receiver( or TSOP1736) used here to receive the signals from remotes. These IR sensor having the capability to receiving 36 KHz IR signals from any remotes.
The timer circuit used here is to take the output from IR sensor. Then it is possible to control light or any other appliances.
- TSOP 1738
- IC 7805
- IC 555
- IC 4017
- 9V Relay
- Transistor BC547
- Diode 1N4007
- Resistor 100KΩ = 2, 330Ω
- Capacitor 0.01μF = 2, 10μF
- Battery 9V
Construction & Working
This relay circuit required 9V supply and it get from battery. This circuit receives any IR signals from any IR remotes and make it turn ON/OFF electrical appliances. For a sample, we can choose a common bulb here to glow the circuit up. The bulb is connected in relay as between common and Normally-Open terminals of the relay.
LM7805 is the 5V regulator IC used here for supply to IR sensor, timer and counter IC. The output of sensor TSOP 1738 is connected with timer IC’s trigger Pin. The IR signals Received by TSOP 1738, produce output and triggers the timer IC. Here, timer IC is configured as mono-stable multi-vibrator and hence produce single pulse signals depends on the timer Resistor R2 and Capacitor C2 values.
The timer output is applied to clock input of IC4017 and this IC counts the clock. If the count begins from zero, then transistor Q1 output becomes high and then BC547 transistor gets turn ON and it makes the relay connected with ground. Then, relay coil get power and attracts the level to Normally-Opened contact. Then the bulb gets power supply and it will start glowing.
If the count begins from one (Q1 is high) then output of Q2 becomes high. And the signal biased to reset pin 15 and hence everything on counter gets reset. So, the transistor Q1 becomes low (zero), then transistor becomes turn OFF. So, the relay also gets turn OFF. This leads to the disconnection of bulb from supply and bulb become OFF.