Introduction
To reduce human effort, muscle power and to make the food serving process uniform as well as effective, we are making an automatic food serving machine for marriage parties. By using modern engineering, technology and automation mechanism this machine is designed to serve food one person at a time which will avoid gathering of hunger guests at parties.
Block Diagram
Materials required
- Electric Motor
- Hopper
- Motor Drive Circuit
- Timer Circuit
- Conducting Wire
- Metal arm
- Hard Board
- Sun Board.
- LASER
- LDR
- Relay
- 555 IC
- 7805 voltage regulator
Transformer
It consists of two coils of insulated copper wire linked by an iron core. Transformers are used to step up (increase) or step down (decrease) AC voltages. Energy is transferred between the coils by the magnetic field in the core. There is no electrical connection between the coils. Here we have used a shell type step down transformer which step downs 230 volt AC to 12 volt AC.
LDR
LDR Stands for Light Dependant Resistor. LDR is a kind of variable resistor and its resistance value varies depending on the intensity of light falling on it. In dark, LDR offers extremely high resistance as high as 10 Mega Ohm but it reduces to 100 Ohms or less in bright light. So LDR is an ideal light sensor when our circuit has a dependency parameter as sun light. You can use a 5mm diameter LDR here.
Capacitor
A capacitor stores electric charge. Capacitors used here are mica and electrolytic type.
Resistor
A resistor restricts the flow of current. The resistors used here are carbon film and quarter watt type.
Variable Resistor
There is a provision to adjust its resistance value by rotating it through a screw driver.
Transistor
A transistor amplifies current. It can be used with other components to make an amplifier or switching circuit. BC 547 is a general purpose transistor. It is an npn epitaxial silicon transistor. Its maximum collector current (DC) is 100mA.
LED (Light Emitting Diode)
It is a transducer which converts electrical energy into light energy.
Diode 1N4007
These are general purpose diodes. These diodes have high current capability and low forward voltage drop. The average rectified output current is one ampere.
NE 555
The 8-pin NE 555 timer is the most useful ICs ever made in the world. Its popular name is timer IC. It is used in many electronics projects. Just adding a few external components, it can be used to construct so many circuits. The 555 has three operating modes: Monostable mode, Astable mode and Bistable mode. It can withstand maximum supply voltage up to 16 volt. It has a maximum power dissipation up to 600mW.
Relay
Generally relay is defined as an electromagnetic switch. The relay used here is a 12 volt ice cube type.
Motor
A motor is a device which converts electrical power into mechanical power. Here we have used a small 12 volt permanent magnet type geared DC motor.
7805 voltage regulator
The 7805 voltage regulator IC gives us a constant 5 volt DC power supply from a 12 volt rectified output voltage. So , where the rest of the 7 volt goes ? Actually, the rest 7 volt goes nowhere. It is dissipated as heat in the heat sink provided to the voltage regulator IC.
LASER(Light amplification by stimulated emission of radiation)
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation.
Working
Sensor activates the motor when a human shows his food plate below the metal hand. Motor rotates for a predetermined specific time due to the timer circuit. As a result metal arm attached to the motor shaft collects the required amount of food to serve. When metal hand position is nearly vertically downward, food falls automatically on the plate due to gravity force. This process continues for the next human standing in a queue for getting food.
Circuit diagram for bridge rectifier
Circuit diagram for LDR as a sensor
Circuit diagram for timer
Advantages
- Human effort to serve food is reduced.
- Makes the food serving process easy and effective.
- It somehow manages social distancing due to its only one person at a time unique serving feature and avoid gathering of hunger people near serving place at parties.
