Motion Sensitive Automatic Light Using 4017 & IR Sensor

In this project, we are going to build a motion-sensitive automatic light using 4017 and an IR sensor. When somebody attempts to cross the sensor, the light will automatically turn on and it will glow consistently. And after coming back to the sensor range, it will automatically turn off.

This circuit utilizes an IR LED and an IR receiver to detect an object. Also, it uses an LM358 op-amp ic and a 4017 decade counter to operate the whole switching program.

People are volatile sometimes to switch off home appliances. To do this easily, we build this project. This may lower electricity wastage as well as light’s lifetime.

Principle Behind Motion Sensitive Automatic Light

When somebody enters a room by crossing the sensor, the IR sensor sends a clock pulse to 4017 ic. Then the light turns on and after the person exits the room it will turn off immediately.

Each time when IR sensor detects an object, it sends the clock pulse to the 4017 decade counter. By that principle, 4017 ic is set to ON state and after receiving another clock pulse it goes back to the previous state (OFF state).

CAUTION: Please take proper safety precautions while working on mains power supply as it is 230V AC source.

Project

Circuit Diagram

Components Required

• LM358 Op-Amp
• 4017 Decade Counter
• BC547 NPN Transistor
• IR LED & IR Transmitter
• 100uF/25V Capacitor
• 1000uF/25V Capacitor
• 220 Resistor (x4)
• 10K Resistor
• 10K Trimmer Pot
• 1N4007 PN Diode
• 5V Relay
• LED (Red, Green)
• 9V Battery

Working Principle of Motion Sensitive Automatic Light

The working of an IR LED is to emit IR rays continuously. So when an object comes to these rays, some of these will reflect by this object and go back to the IR receiver.

Then LM358 op-amp compares the voltage between the IR receiver and the predefined value. If any voltage fluctuation is detected happened by the IR receiver, then the output of LM358 becomes high. The clock pin (pin 14) of 4017 IC is connected to the output pin (pin 1) of LM358 ic.

So the output of the op-amp is then received as an input to the 4017 ic and it changes the current state of the output pin (pin 2). The output of the 4017 decade counter is connected with the base of the BC547 NPN Transistor. The transistor acts as a switch, so the transistor then becomes high.

After that, the current can flow through the 5V relay and that’s how the circuit will turn on the connected load.

In the same process, when the IR receiver detects the second clock pulse, it becomes low. Thereafter the load connected with the 5V relay will turn off.

Applications of Motion Sensitive Automatic Light

• Mostly used in washroom lights to switch on and off.
• It is also can use in home appliances like AC, fan etc to reduce electricity bills.