Solar panels gives more power when they face the sun directly.
Manual turning is hard and wastes time.
Automatic solar tracker moves panel automatically with sun.
This Solar Tracker Circuit using LDR and Op-Amp uses simple parts and with no Arduino or microcontroller.
Main parts are two LDR sensors, TDA2822 IC, few resistors, solar panel and DC motor.
Circuit Working:
Parts List:
| Component Name | Specification | Quantity |
|---|---|---|
| Resistors | 220Ω | 2 |
| LDR | 2 | |
| Semiconductors | IC TDA2822 | 1 |
| Solar Panel 5V or 6V | 1 | |
| DC Motor 5V | 1 | |
| SPST Switch | 1 | |
| Diode 1N5402 | 1 | |
| Battery or Power Supply 5V DC | 1 |
In the above circuit diagram two LDRs sense light from left and right sides.
When light is equal, both LDRs have same resistance.
IC TDA2822 compares voltage from both LDRs.
If one LDR gets more light then its resistance goes low.
Voltage difference changes output of IC.
The output drives DC motor to rotate solar panel.
When both LDRs get same light again then motor stops.
So the panel always faces the sunlight direction.
Connect push SPST switch to circuit for manual control of solar tracker.
Add 1N5402 diode in circuit to stop reverse current.
It protects parts from voltage problem and damage.
Keeps circuit safe and stable.
Formulas:
Below is the formula for Solar Tracker Circuit using LDR and Op-Amp:
Each LDR and resistor make a voltage divider.
Formula: Vout = (R / (R + LDR)) × Vcc
where,
- Vcc is the total supply voltage example 5V or 12V
- R is the fixed resistor value example 220Ω
- LDR is the resistance of light sensor which changes with light
- Vout is the voltage taken from between R and LDR
How to Build:
To build a Solar Tracker Circuit using LDR and Op-Amp follow the below steps for connection:
- Collect all parts same like circuit diagram.
- Output(1) pin 1 of IC1 TDA2822 goes to one side of DC motor through diode D1
- Supply Voltage pin 2 of IC1 connect to one side of solar panel through SPST switch.
- Output(2) pin 3 of IC1 connect to other side of DC motor.
- Ground pin 4 of IC1 connect to other side of solar panel.
- Input- (2) pin 5 and Input+ (1) pin 7 join between resistors R1 and R2.
- Input+ (2) pin 6 and Input- (1) pin 8 join between LDR1 and LDR2.
Conclusion:
This is a simple and low-cost Solar Tracker Circuit using LDR and Op-Amp.
It does not need Arduino or programming.
It saves energy and increases solar efficiency.
We can improve it using motor driver IC like L293D for stronger motors.
This project is good for beginners in electronics and renewable energy.