Do you find it hard to get up from your cozy bed at night, just to turn off the lights? Do you want to operate your home appliances simply by a click of your TV remote? Home appliances include all types of electrical equipment available in your home. It does not matter whether it is a washing machine or a coffee maker. So, if you are lazy enough or maybe just love using technology, this project is for you!
We will walk you through the build process of the infrared-based wireless switch. In simple terms, it is a switch that you can operate using your TV, DVD player or any other remote. The best part of this project is that PCBGOGO, a PCB manufacturing company based in China, makes it super easy to construct it. You no longer need to go through the hard and time-consuming process of making a PCB yourself. PCBGOGO has your back! And they don’t even charge much!
Figure 1 shows the circuit diagram of this project. The wireless switch can be simply made by using TSOP1738 infrared receiver, decade counter CD4017 and other easy to find components.
So, based on Figure 1, we will need the following components to begin making this wireless switch:
- Decade Counter CD4017
- Infrared Receiver TSOP1738
- 1N4007 Diode
- 7805 IC
- BC558 and BC548 transistors
- 100, 220k, 470 and 1k ohm resistors
- Two LEDS
- 33μF, 100μF and 0.1μF Capacitors
- Relay 5V, 100 Ω
Home remote controls such as your TV’s remote, emits infrared rays when any button is pressed. Each button produces its unique pattern of infrared waves. So, when you will press a button on your TV remote, IR rays will fall on TSOP1738 infrared receiver. Its output pin 3 will go low as it is active low and the transistor Q1 will amplify the signal to feed it to the clock input of CD4017.
Assuming that the decade counter is at reset state, output Q0 will go high and other outputs will be low. LED D2 will be glowing at this time, indicating that the appliance is in the off state. Clock signal will be generated in the decade counter as soon as it gets signal from the transistor Q1. Output Q1 will go high and LED D1 will start to glow. Transistor Q2 will also turn on and the relay will be energized. LED D1 will stop glowing at this time.
Now, to turn off the appliance, you will need to press the remote again. Q0 will again become high and LED D2 will start to glow, indicating that your appliance has been turned off. CD4017 is working as a bistable multivibrator as we have connected the output Q2 (4th pin) with Reset MR (15th pin). 16th and 8th pins are VCC and GND pins, respectively. 13th pin is the enable pin. It is connected to the ground since IC is active low.
Some other noteworthy connections are the 2nd and 1st pins of TSOP1738, they are the VCC and GND pins respectively. The 100 Ω resistor and 33μF capacitor are used to smooth the noise in power supply.