Nowadays, street light systems in the major cities are growing quickly. The important considerations in the various technologies like electrical and electronics are cost-effective, automation and also power consumption.There are various types of street lighting systems are implemented to maintain and control the lighting systems. These are used to control and reduce energy consumption. The street light controlling is one of the main developing systems in India to save the energy. This article shows the streetlight glowing system detecting the vehicle movement.
Street Light System that Glows on Detecting Vehicle Movement
High-intensity discharge lamp (HID) presently used for the urban street light system is based on the principle of gas discharge, thus the intensity is not controllable by any voltage reduction method as the discharge path is broken.
Present Day Technology
White Light Emitting Diode (LED) based lamps are soon replacing the HID lamps in the street light.As these LEDs can switch faster than HID lamps we can apply PWM concept to these LEDs.LEDs consume less power compared to HID lamps.The lifetime of LEDs is also more.
Hardware and Software Requirements
This project is used to notice the movement of a vehicle on highways to activate the lights when the vehicle is in front of the lights and to turn OFF the lights when the vehicle passes away from the lights. By using this system we can conserve the energy.
The hardware and software requirements of the street light system that glows on detecting vehicle movement include 8051 series Microcontroller, LEDs, Voltage Regulator, Resistors, Capacitors, Crystal, Transistors, Diodes, Photodiodes, IR LED, Keil compiler and Language: Embedded C or Assembly
- The circuit uses standard power supply comprising of a step-down transformer from 230v to 12v and 4 diodes forming a Bridge Rectifier that delivers pulsating dc which is then filtered by an electrolytic capacitor of about 470microf to 100microF.
- The filtered dc being unregulated IC LM7805 is used to get 5v constant at its pin no 3 irrespective of input dc varying from 9v to 14v.
- The regulated 5volts dc is further filtered by a small electrolytic capacitor of 10 micro f for any noise so generated by the circuit.
One LED is connected to this 5v point in series with a resistor of 330ohms to the ground i.e. negative voltage to indicate 5v power supply availability.
- Compatible with MCS®-51 Products
- 8K Bytes of In-System Programmable (ISP) Flash Memory
- Endurance: 10,000 Write/Erase Cycles
- 4.0V to 5.5V Operating Range
- Fully Static Operation: 0 Hz to 33 MHz
- Three-level Program Memory Lock
- 256 x 8-bit Internal RAM
- 32 Programmable I/O Lines
- Three 16-bit Timer/Counters
- Eight Interrupt Sources
- Full Duplex UART Serial Channel
- Interrupt Recovery from Power-down Mode
- Watchdog Timer
- Dual Data Pointer
- Fast Programming Time
- A photodiode is a type of photodetector capable of converting light into either current or voltage, depending upon the mode of operation.
- Photodiodes are similar to regular semiconductor diodes except that they may be either exposed (to detect vacuum UV or X-rays) or packaged with a window or optical fiber connection to allow light to reach the sensitive part of the device.
- An IR LED, also known as IR transmitter, is a special purpose LED that transmits infrared rays in the range of 760 nm wavelength.
- Such LEDs are usually made of gallium arsenide or aluminum gallium arsenide. They, along with IR receivers, are commonly used as sensors.
- The appearance is same as a common LED. Since the human eye cannot see the infrared radiations, it is not possible for a person to identify whether the IR LED is working or not, unlike a common LED.
- To overcome this problem, the camera on a cell phone can be used. The camera can show us the IR rays being emanated from the IR LED in a circuit.
PWM(Pulse Width Modulation)
- The term duty cycle describes the proportion of on time to the regular interval or period of time; a low duty cycle corresponds to low power because the power is off for most of the time.
- Duty cycle is expressed in percent, 100% being fully on.
- The main advantage of PWM is that power loss in the switching devices is very low. When a switch is off there is practically no current, and when it is on, there is almost no voltage drop across the switch.
- PWM works also well with digital controls, which, because of their on/off nature, can easily set the needed duty cycle.
- The longer the switch is on compared to the off periods, the higher the power supplied to the load is.
Operation of Project
There are two basic modes of operation,
- The transition of streetlights from dark to the bright state.
- The transition of streetlights from dim to the bright state.
In the first mode of operation, when the vehicle is not present, all the streetlights will be in dark state. When a vehicle is sensed then the window of streetlights is illuminated in front of the vehicle.
In the second mode of operation, initially, when the vehicle is not sensed, all the streetlights will be in the dim state. This is achieved by use of pulse width modulation technique through the program stored in the microcontroller.
When a vehicle is not present on the highway, then the streetlights are made to glow for about 1ms and then for 100ms, they are switched off. Thus, we get streetlights with less brightness.
When a vehicle is sensed, all the streetlights are illuminated for 1ms and the window of streetlights are illuminated for 100ms. Thus we have a PWM wave of 99% duty cycle.
Furthermore, this project can be developed by using an appropriate sensor for noticing the street light system failure, and then sending an SMS to the control section through a GSM modem for suitable action.
Thus, this is all about the street light system that glows on detecting vehicle movement. The applications of this system mainly involve in highways, real-time street lights, hotels, parking areas, and restaurants, etc. The benefits are; low cost, more lifespan and energy can be saved.Furthermore, any queries regarding this topic or street light system based projects, please give your valuable suggestions by commenting in the comment section below.