AUTOMATED NIGHT LAMP WITH IR REMOTE CONTROL

An automatic night lamp, as its name implies, can turn on and off by itself without requiring any manual operation. It detects whether it is day or night by measuring the light levels in its environment. By integrating infrared (IR) remote control functionality, users can easily adjust settings from a distance.

LDR circuit

1. Light Dependent Resistor (LDR)
2. LM358 Op-Amp
3. Resistor 4.7KΩ *3
4. Resistor 10KΩ
5. BC547 transistor
6. 1N4007 diode
7. 5V relay
8. 230V bulb

IR remote circuit

1. Capacitor 1µF
2. 5V relay
3. BC547 transistor
4. Resistor 1KΩ *2
5. Resistor 100KΩ
6. Resistor 10KΩ
7. Resistor 100Ω
8. LED bulb
9. CD4017 IC
10. BC557 transistor
11. Capacitor 10µF
12. VS1838 IR receiver
13. IR transmitter bulb

Power circuit

1. 12v Transformer
2. 1N4007 diode *4
3. 7805 voltage regulator
4. Capacitor 1000UF

To bring the automated night lamp to life, utilized EasyEDA for designing the PCB. This tool allowed us to create a precise circuit schematic and convert it into a fully functional PCB layout.

The circuit integrates an LDR (Light-Dependent Resistor) for automation based on natural light with the capabilities of an IR remote for manual control. This is the breakdown:

Automatic Control Using LDR

The level of natural light is detected by the LDR. As the surroundings gets darker, the LDR's resistance increases, causing the LM358 operational amplifier to activate the lamp. On the other hand, in bright lighting, the lamp shuts off.

IR remote control

An IR receiver module processes commands from the IR transmitter (remote control). These signals are fed to the CD4017 decade counter, which toggles the lamp ON or OFF based on the user input.

In this project we created an automated night lamp using LM358 IC. The main purpose of this project is for turning on & off the lamp automatically without need of human action. Also from IR remote we can control the lamp manually from the push button. It sense the light intensity from surrounding & finds whether it’s day or night. It automatically turns on when the surrounding is dark , it turns off when it receive light from surrounding. For that purpose we used a LDR. It is a sensor which is a particular kind of a resistor whose resistance decreases when expose to light. The LDR is placed in a potential divider network. Voltage across the LDR is given to the positive terminal of LM358 IC. To create a reference voltage we used 4.7 KΩ resistors as voltage divider. LM358 is an op-amp which compares the voltage level as it’s two inputs and gives output accordingly. The output of the comparator is given to the BC547 transistor. It acts as a switch. Since enough voltage appears across the base- emitter junction the transistor conducts and current passes through this relay coils. So relay switch contacts and bulb close. Bulb is connected to the NO pin of relay as it should be off when the relay coils are not energized. The bulb is connected to the 230V supply.

When moving on to the IR remote circuit ,

When an IR remote button is pressed, it emits an infrared signal, which is detected by the VS1838B IR receiver. This causes the output pin of the receiver to go LOW. The output pin is connected to the base of a BC557 PNP transistor. When the receiver output goes LOW, the BC557 transistor turns ON.

The BC557 is connected to the CLK pin (pin 14) of the CD4017 IC. When the BC557 is activated, it sends a HIGH pulse to the CLK pin. Each HIGH pulse at the CLK pin changes the state of PIN-2 of the CD4017. For instance, if PIN-2 is LOW, it becomes HIGH after receiving a pulse and remains HIGH until the next pulse. When PIN-2 is HIGH, it activates a BC547 NPN transistor, allowing current to flow through the relay coil. This, in turn, powers the load connected to the relay. Pressing the IR remote button a second time sends another clock pulse to the CD4017, toggling PIN-2 from HIGH back to LOW. This deactivates the BC547 transistor, cutting off current to the relay coil and turning off the connected load.

Here's how it works step-by-step:

Input Transformer (12V AC):

The input (P1) receives 12V AC from a step-down transformer, which reduces the mains voltage (230V AC) to a safer 12V AC.

Bridge Rectifier:

The four diodes (D1, D2, D3, D4) form a full-wave bridge rectifier. This converts the AC voltage from the transformer into pulsating DC voltage.

Smoothing Capacitor (C2):

The capacitor (C2) smooths the pulsating DC output from the rectifier, reducing the ripple and providing a steady DC voltage.

Voltage Regulator (U2 - LM7805):

The 7805 linear voltage regulator ensures a stable 5V DC output regardless of variations in input voltage or load conditions. This is achieved through internal circuitry that regulates the voltage.

Output Capacitor (C3):

The capacitor (C3) improves the stability of the output by further smoothing any minor ripples after regulation.

Output Terminal (P2):

The regulated 5V DC is available at P2 for powering external circuits.

1. Energy Efficiency: The lamp turns ON only when it's dark, saving electricity.
2. Convenience: IR remote control allows easy manual operation.
3. Safety: Relays provide electrical isolation, reducing the risk of accidents.
4. Scalability: This circuit can be adapted for other appliances or higher wattage lamps.

Home Lighting: Ideal for hallways, bedrooms, and bathrooms where manual switching might be cumbersome.

Outdoor Lighting: Commonly used in gardens and pathways to enhance safety without requiring human intervention.

Public Spaces: Useful in parks and public areas where lights need to be activated automatically at dusk and turned off at dawn