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Automatic solar-powered night light | Automatic solar-powered night light auto on-off.
Automatic Solar Powered Night Light
The automatic solar powered night light is a convenient and energy-saving lighting solution, operating by using solar energy to provide light at night. Below are detailed information about how it works and the benefits of this type of light.
Also we want to save electricity and power for that, So today I will discuss about solar powered automatic night light or solar night light. This circuit can provide upto 4 watts and is easy, efficient and reliable. So let’s discuss about solar powered automatic night light or let’s say solar powered automatic night light/dark light detector light.
1. Operating Principle
- Basic Structure
- Solar Panel: Converts sunlight into electrical energy.
- Charge Controller: Manages the charging process of the battery and protects it from overcharging or over-discharging.
- Rechargeable Battery: Stores electrical energy to power the light during the night.
- LED Light: Provides illumination. LED technology is commonly used due to its high brightness and low power consumption.
- Light Sensor: Detects changes in light to automatically turn the light on or off.
Rechargeable solar powered automatic night light circuit.
Solar panel 12v 5watts/10watts
D1, D4 1N5400-2pcs
D2, D3 1N5351BRL-2pcs
D5, D6, D7 LEDs 1 Watt -3pcs[I recommend using 2 for better brightness/but if you are using a 12v lithium-ion battery pack then it is fine.]
LDR1 LDR -1pcs
R2 160K-1pcs
Q1, Q2 TIP122 -1pcs
C1 2200uf-1pcs
C2 100uf-1pcs
12v lithium-ion battery 2000-4000mah or 12V 2ah- 4.5ah lead battery
The above circuit uses a 12v solar panel with a power of up to 5-10watts to charge a 12v battery during the day. The battery can be a 12v lithium-ion battery or a lead acid battery or an SMF battery or a Gel battery.
The charging is regulated by a 14v Zener to keep the battery at 12.8-13V. The battery is charged continuously during the day but cannot be overcharged as the solar panel only supplies voltage higher than the initial voltage of the battery when the sunlight is strong enough and the concentration is also good. As I suggested 12v 2000mah-4000mah lithium-ion battery, so the total battery capacity is around 40Wh (according to 4000mah) and the solar panel only supplies let’s say 10w which supplies voltage definitely higher than 12v in good sunlight. So it will also take 4-5 hours to charge the battery and this is only until the sunlight is concentrated on the solar panel which will be good. So any battery with mah or ah value will not be overcharged.
The sensitivity of the LDR is set by R2 160k since the light starts at 6:30 pm. Transistors Q1 and Q2 drive the 1 watt LEDs.
How does LDR control Circuit? How does the circuit actually work?
An LDR is a light sensor which has minimum impedance when light falls on it at high intensity and its impedance is highest when placed in darkness. So in daytime when light falls on LDR its impedance is minimum around 100ohm which causes the base of transistor Q1 and Q2 to short circuit to ground and this makes the transistor off because of ground connection and the LEDs are not lit and the battery is just charging.
When there is no daylight, the LDR does not receive any light and this increases the impedance of the LDR to its maximum. This creates a strong barrier between the base of the transistor and ground and the base receives power through the 160k resistor. This turns on the transistors Q1 and Q2 making the LEDs glow brightly at night through the battery.
Instruct
Use a small heatsink suitable for transistors Q1 and Q2 such as TIP122 transistor. Also make sure that the position of the LDR is such that only daylight/sunlight can shine on it and not the output of the active LEDs. Also make sure that the circuit is waterproof (arranged in some kind of box or some kind of arrangement).
For those using TIP122 for the first time, make sure that the pins of TIP122 are not arranged like a normal transistor, instead, they are 1.base, 2.collector and 3.emitter. Refer to Google if you are new to electronics projects and MOSFET.
Below I have added a small video of the simulation and shows how this circuit actually works.
4. Note When Using
- Installation location: Ensure that the solar panel is placed in a position with direct sunlight for a long period of time.
- Regular maintenance: Clean the solar panel and check the operation of the light sensor to ensure optimal performance.
- Battery replacement: Regularly check and replace the charging battery as needed to maintain lighting performance.
Conclusion
Solar-powered automatic lights are an efficient and environmentally friendly lighting solution for outdoor areas. With automatic operation, energy savings, and low maintenance, they are an ideal choice for nighttime lighting without relying on the grid power source.