Introduction

Most of the people hesitate to open the cover of a dust bin while throwing litter, because they think that it is dirty. In this project we are attaching an automatic mechanism to solve this problem. The Solar powered Smart Dust Bin project will open and close its cover automatically. It is simple and effective.

Components required

NE 555

LDR

LASER

Relay 12 V

LED

Resistors 10 kΩ, 1 kΩ, 77.470 kΩ

Capacitor 0.01 µF, 47 µF

Variable resistor 10 kΩ

Switch

DC motor

4 V battery

Solar panel

Transistor BC 547

Working

The project is assembled on the board according to the circuit diagram. The LASER and the LDR set is placed on the frame with proper alignment . The power supply is provided by solar panel.

When a person moves his hand over the dust bin cover to throw litter, it opens its cover automatically and after that it gets its previous state back. The opening and closing mechanism of the cover is triggered when the LASER beam is disturbed by movement of human hand. There are two sets of the above circuit for two sets of LASER and LDR combinations.

When switch 1 and 3 of the H-Bridge operates simultaneously the dc motor rotates in forward direction and when switch 2 and 4 of the H-Bridge operates simultaneously the dc motor rotates in reverse direction. The pulley and thread arrangement pulls the dust bin cover when motor rotates in forward direction. The dust bin cover is free to be closed when motor rotates in reverse direction due to action of gravity. Switch 1, 2, 3, 4, are four 12 volt ice cube relays here. The motor rotates only for a fixed time period in both the directions due to the timer circuit used here. In this particular case the time period is approximately 4 second. The resistance R and the capacitor C in the timer circuit are responsible for this time period.

Time in second = 1.1 R C

                       = 1.1 (77.470 kΩ)( 47 µF)

                           = 4.005199

Advantage

1 Keeps the work environment neat and clean.

2 No disgusting smell spreads from the bin in air as the bin cover is closed.

3 It uses free energy for its operation.