Introduction Dental care has been an important part of personal well-being for many years. Evolving from the ancient toothpicks, traced back over five thousand years in ancient civilisations, the traditional toothbrush as we know it today was developed in the seventeenth century . Since then the toothbrush has maintained the idea of being a “brush” while other aspects such as handle shape and toothbrush material have changed over time to become the toothbrush as we know it today. Efficiency has become necessary in the modern age due to the massive human population and societal pressures on time. Studies describe the possibility of improving the efficiency of the toothbrush by using a electric toothbrush. It has been found that the removal of oral gingivitis and plaque is related to the frequency of brushing and the technique used. With an electric smart toothbrush, the frequency of brushing can be adjusted to be much more optimal than human brushing frequencies on the teeth. The smart toothbrush can also be integrated with sensors to aid the user in practising more efficient tooth brushing techniques. Recently, with the development of faster smaller and faster microcontrollers, it is possible for the toothbrush to process even more data while being lightweight and compact. Human machine interface and communication has therefore become an important factor for product marketing and development. In this project, the design will explore all these aspects and seek to produce a simple prototype using basic resources to achieve a smart system aiding the user to operate the electric toothbrush. Finalized Specifications  Clock-wise and anti-clockwise rotation  Adjustable speed  Long head for better cleaning  Ultra violet light to kill germs  Programmable brushing modes for different requirements  Timer to automatic stop brush to save energy  Long lasting battery upto 2 months(assumed brushing 2 times a day and 2 mints for a session )  Led display showing current states of battery , mode, speed and countdown timer  Curves in design for better grip  Mouth washer tank Systems Design and Integration Toothbrush will be controlled using an surface mounted AVR Atmega8 microcontroller, It will use simple dc motor controlled using PWM technique. LED display is integrated so to display current states Motor Driver IC As the microcontroller is unable to provide the required current to drive the motor, an external IC driver is used and controlled by the Atmega8. The L293 driver chip is designed to drive currents of up to 1 A at voltages from 4.5 V to 36 V

1. Electrical toothbrush
CAD SEMESTER PROJECT
submitted by:
Lutif Ali Mandhro (K11-2193)
SECTION c

2. Introduction
Dental carehas been an important part of personal well-beingfor many years. Evolvingfrom the ancient
toothpicks,traced back over fivethousand years in ancientcivilisations,the traditional toothbrush as we know
it today was developed in the seventeenth century . Sincethen the toothbrush has maintained the idea of
being a “brush” while other aspects such as handleshapeand toothbrush material have changed over time to
become the toothbrush as we know it today.
Efficiency has become necessary in the modern age due to the massivehuman population and societal pressures
on time. Studies describethe possibility of improvingthe efficiency of the toothbrush by usinga
electric toothbrush. It has been found that the removal of oral gingivitisand plaqueis related to the
frequency of brushingand the technique used. With an electric smarttoothbrush, the frequency of brushing
can be adjusted to be much more optimal than human brushingfrequencies on the teeth. The smart
toothbrush can also beintegrated with sensors to aid the user in practisingmore efficienttooth brushing
techniques.
Recently, with the development of faster smaller and faster microcontrollers,itis possiblefor the
toothbrush to process even more data while being lightweight and compact. Human machineinterface and
communication has therefore become an important factor for product marketing and development. In this
project, the design will exploreall theseaspects and seek to produce a simpleprototype usingbasic resources
to achievea smart system aidingthe user to operate the electric toothbrush.
Finalized Specifications
 Clock-wise and anti-clockwise rotation
 Adjustable speed
 Long head for better cleaning
 Ultra violet light to kill germs
 Programmable brushing modes for differentrequirements
 Timer to automatic stop brush to save energy
 Long lasting battery upto 2 months(assumed brushing 2 times a day
and 2 mints for a session)
 Led display showing current states of battery , mode,speed and
countdown timer
 Curves in designfor better grip
 Mouth washer tank
Systems Designand Integration
Toothbrush will becontrolled usingan surfacemounted AVR Atmega8 microcontroller,Itwill usesimpledc motor
controlled usingPWMtechnique. LED display is integrated so to display currentstates
Motor Driver IC
As the microcontroller is unableto provide the required current to drive the motor, an external IC driver is
used and controlled by the Atmega8. The L293 driver chip is designed to drivecurrents of up to 1 A at voltages
from 4.5 V to 36 V

3. Display
This model uses LED display to communicate with user itshows current mode , battery state , rotation of motor
and its direction and also shows countdown timer to keep user up to date, the mode setting is also doneusing
buttons with LED display and the responseto each button is communicated to user through this LED display.
Power Module
This model uses a pair of 1.5A non-rechargeableAA sizebatteries the power is fed to main circuitthere power
module circuitcontainingVoltagedoubler circuitand voltageregulator circuitfulfillsthedifferent voltage level
requirements of the respective components and modules .
Motor
This module uses the simpledc motor to rotate the brush head the motor is controlled by motor drivingIC L293NE.
Motor generates 2500 rpm which is then controlled by a set of gears the one set reduces the RPM and increases
the torque the other on changes the rotation from one axis to other.

4. Motor Driver Chip
The L293NE motor driver chip circuithas chip enableon port 1 and Vcc on port 8 and 16, it seemed it required
both sideof the chip to be correctly connected to Vcc and ground to allowthe use of left side. Pin 2 and 7 are
left floatingas they are for controllingdirection which isnotnecessary in this project.Grounding either will
trigger the motor to turn in the oppositedirection.Pin 3 and 6 are connected to the motor, in this casethe
connection is to a jumper for the motor to connect to. Pins 4,5, 12 and 13 are all grounded.
Different views of the model are