Hello Engineers. In today’s world, Technological advancement, Automation, and Free/ Clean energy are a boom and is a necessity too. Everybody wants to automate their boring stuff, save their time. Also, free and clean energy is always appealing and need if it’s about Electricity. Like how helpful and energy efficient will be a smart automatic vehicle detection solar street light. A street light that runs on free energy and is activated only during night when anything is motion is detected. Saving the country’s electricity as well as it’s automated and glows only when it detects an object in motion.
The circuit is very interesting as well as easy as it’s not using any kind of microcontroller, yet very effective. So, let’s start with our topic ” smart automatic vehicle detection solar street light or smart automatic solar street light “, ” smart automatic vehicle detection street light system “.
A very smart solar automatic street light with a vehicle auto-detection system is having a solar panel to sense daytime and battery charging. As well as PIR motion sensor used for vehicle or moving object detection.
Circuit for smart automatic vehicle detection solar street light
Materials and Components required
- PIR sensor – 1pc
- Solar Panel 12 v 10 watts -18w ( SOLAR Panel 10watt buy)
- R1 1k
- R2 680R
- R3 5K6 or 5.6 K ohms to 6K2
- R4 68R
- R5 100r
- D1 1N4007
- RELAY 12V
- Q1, Q3 TIP 122
- Q1 BC337 or TIP122
- LM7808 voltage regulator
- C1 330n
- C2 100n
- C3 1000uf- 2200uf 16v
- 6V 7ah – 10ah SLA(Sealed lead acid ) battery ( Buy from Amazon )
- D2-D9 1Watt white LEDs
- 1N4007 between 7808 regulator output and NO pin of the relay
Working of Smart Solar street light
The circuit diagram and the components require are already mentioned above. As I have already explained and as the name suggests Smart automatic vehicle detection solar street light. This is a smart street light that only glows during the night time and that too only when it detects any motion. In addition to it’s smart features it totally runs on free energy as it’s solar charged during day time automatically. As shown in the circuit diagram, a solar panel is there to charge the battery backup during the day time. Apart from charging the battery, it’s also working as a daytime sensing element.
In the daytime, when sunlight falls on the panel, it activates the Q2 which then activates the 12v relay. Along with this, the 12 v to 8 v converter LM 7808 circuit is also activated. With the relay’s activation, the COM pin is now connected to the NO( normally open) PIN. The NO is connected to 7808 ICs output so that the battery can be charged during the day time.
Till the time the solar panel is generating output from the sunlight, the battery keeps charging and LM7808 keeps converting 12v-8v. The battery will not be overcharged due to the efficiency of the solar panel’s output is only up to 5-6 hours the whole day. Suppose,
If we are using 12v 10watts solar panel with a 6v 7 ah battery, and output from regulator is 8V1A then the charging time is 5.08 hours theoretically. But, in practical situations, this can be 5.5 hours approx. due to factors like heat dissipation and power loss.
During Evening or Night time in the Absence of the Daylight.
When the solar panel stops producing any output or required output, the relay is off. With the relay off, the COM pin is again connected back to NC pin which is normally connected naturally to the com.
So, during the night the charged battery starts serving the PIR sensor(click to understand PIR sensor working). On sensing any object or motion, the sensor then gives the TTL output to the Q1 for a short time delay of a few seconds. Q1, on getting activated provides Q2 access to the ground of the battery which then completes the circuit. Then this makes LEDs panel to glow for a short while even after the object has been passed.
If the object is still there, then PIR sensor is continuously ON and also the light is continuously glowing.
Q2 governs the voltage regulation and LED driving responsibility. Once no motion is detected after PIR stops giving output to Q1 which turns it off, as a result, the Q2 circuitry is also turned off.
Choose the battery and number of 1 watt LEDs according to the backup time required. For example, we have 8* 1w LEDs in parallel and a 6v 7ah battery as a power backup. So, theoretically, the backup time will be 5 hours approx. If you use the same power LEDs load with a 6v 10ah battery then the backup will be 7.5 hours theoretically, but practically it will be less up to 6.8 to 7 hours.
Here the battery is used in a cycle use from dawn to dusk and dusk to dawn as it’s charging & discharging but also some times in standby mode.
Use heat separate good quality heatsinks with Q2 and Q1. Also, use 10 ah battery for better performance and backup. Use Max of 10 * 1 Watt LEDs for better performance and backup.
So this was all about this circuit design idea, I hope you guys liked it. Subscribe to the newsletter for latest post updates. Thank you.