The growing demand to the save electricity and failure in power supply is difficult and inconvenience. An automatic emergency lamp makes use of LED and too bright because of white LEDs that turn on if mains supply fails and turns off if power resumes. It has its battery charger that stops charging automatically when it is fully charged. The aim of this Low Cost Automatic Energy Efficient Emergency Lamp Using Pulse Width Modulation project is to develop user friendly product and power efficient. The objective of this project is to reduce power consumption by utilizing a low-cost, automatic white LED lamp with PWM.
The circuit has three sections for the charger power supply includes a transformer that steps down (9V,500mA), Bridge rectifier that rectifies transformer output, LM317: voltage regulation, Battery that provides supply when mains fails, and a Zener diode conducts when battery crosses its capacity.
555 timer section controls the LED section by PWM. LED driver section builds around BD 140 and 12 white LEDs connected in parallel. LED section glows when mains fails and blinks using astable operation of 555 and appears fulltime ON because of persistence of vision.
The features include simple circuit where components are easily available at low cost. Automatically switches ON when the mains fails and turns OFF when mains power resumes and has a battery charger that stops automatically when fully charged. It makes our lives simpler and convenient to use. Energy consumption is very less and proves to be more economic for the consumer.
Advantages are efficiency, color, very small size, on/off time, cycling, dimming, slow failure, life time, and toxicity.
The project concluded that there is an innovative improvement in today’s life. This device has added a new look to the traditional lamps. With the use of PWM, wastage of energy has reduced. The cost of this circuit is very less.
Download Low Cost Automatic Energy Efficient Emergency Lamp Using Pulse Width Modulation Electrical and Electronics Engineering EEE Final Year Project Report