Automatic Hand Dryer With Temperature Display

Project and Seminar Material for Computer Engineering

Automatic Hand Dryer With Temperature Display


This project deals on the design and construction of automatic hand dryer with temperature display facility which is capable of drying a wet hand placed under its vent goes of automatically. It corporate a temperature sensing and displays unit which displays the temperature of the blown out air. This system is designed in top-down methodology using passive and active components sensors (LM35 & LDR) at the input to sense temperature and hands respectively. The control unit is made up of signal conditioning unit, voltage comparator and frequency generator, and decimal counting unit.

The output interface comprises transistor, driver, actuator, Electromagnetic relay and a –digit seven segment Display. The sensor are installed at the front of the blower and this device dries with warm air only. When a hand is placed under the vent to block the line of sight of the LASER Diode and LDR, the blower gets actuated and blows warm air. As the hand is removed, the blower stops automatically along side the temperature display. The principle behind the work of this system is that the hands must be opaque enough to block the line of sight of the opto coupler. This removes the stress, time and dangers associated with push button type. The result being automatic hand dryer with temperature display.

Table Of Contents

Preliminary Page(s)

  • Title
  • Declaration
  • Approval
  • Dedication
  • Acknowledgement
  • Abstract
  • Table of Content

Chapter One


  • 1.1 General Description Of The Project
  • 1.2 Background To The Study
  • 1.3 Statement Of The Problem
  • 1.4 Objectives Of The Study
  • 1.5 Significance Of The Study
  • 1.6 Scope Of The Study

Chapter Two

Literature Review

Chapter Three


  • 3.1 Components Analysis
  • 3.1.1 Transformer
  • 3.1.2 Resistor
  • 3.1.3 Light Dependent Resistor (Ldr)
  • 3.1.4 Integrated Circuit (Ic)
  • 3.1.5 Capacitor
  • 3.1.6 Light Emitting Diode (Led)
  • 3.1.7 Transistor
  • 3.1.8 Diode
  • 3.1.9 Relay
  • 3.1.10 Heating Element
  • 3.2 Specification Of Materials

Chapter Four

Construction, Testing And Packaging

  • 4.1 The Block Diagram Of The System
  • 4.2 Power Supply
  • 4.2.2 Sensory Stages
  • 4.2.3 Timer Stage
  • 4.2.4 Switching Stage
  • 4.2.5 Motor And Heating Element Stage
  • 4.3 Testing
  • 4.3.1 Assembling
  • 4.3.2 Troubleshooting
  • 4.3.3 General Precaution
  • 4.3.4 Maintenance Of The System

Chapter Five

Conclusion And Recommendation

  • 5.1 Conclusion
  • 5.2 Recommendation
  • Reference

Chapter One


1.1 General description of the project

This project design and implementation of automatic hand-dryer with temperature display is achieved in several blocks all combined to form one functional unit. The first block in the opto-coupler realized with laser diode and LDR whose output is conditioned by 74LS132 that generates control logic. This control logic is used to bias a transistor switch that energizes the electromagnetic relay which switches the dryer. The control logic is also used to trigger/power the temperature display circuit. This section is realized with IC linear temperature sensor (LM35) whose output is fed to a quad-comparator with Hysteresis. This comparator output reset a frequency generator which is counted by a 2-digit decimal counting unit that displays the temperature of the blowers air in degree calcius. The system dries the hand and displays the temperature using seven segment display.

1.2 Background to the study

The basic function of a hand dryer is to dry hands using an electric source. Hand hygiene is a very important aspect in preventing spread of communicable diseases. Since many disease-caused by germs spread through touch, hand dryers were devised so that people can dry their hands without actually touching the roll of towel available for common use in public restrooms. Hand drying machines not only help in maintaining hygiene, but also help in reducing waste produced by the use of towels.

Some years back, these devices were switched on using a button. When the button was pressed, the device started blowing warm air for drying hands. But nowadays hand dryers have infrared motion sensors installed in them. The device detects motion and automatically turns on when hands are placed for drying. Similarly, it automatically turns off when hands are moved away from the dryer, thereby preventing wastage of electricity.

Warm air is produced by a hand dryer using a heating coil made up of Nichrome, a hybrid of chromium and nickel. The warm air is then blown out of the device through a tube or a vent facing downwards. Hands are placed in the path of warm air coming out of hand dryer for drying. The warmth and pressure of air coming out of the dryer is sufficient to evaporate water from wet hands. First, the air pressure blows off water droplets from the hands and then the warmth dries out the moisture from the hands. Traditional hand dryers need around 45 seconds to dry hands, whereas new-age dryers take around 15 seconds to do this task.

1.3 Statement of the problem

The transmission of bacteria and other micro-organisms is most likely to occur fromwet skin than from dry skin. Careful hand drying is a critical factor determining the level of touch-contact associated bacterial transfer following hand washing. Hence, the proper drying of hands should be anintegral component of effective hand hygiene procedures in health care settings.

Cloth towel, paper towel and electric air hand dryer are commonly used to dry washed hands.Although there is wide consensus that hand drying is an essential part of hand hygiene process, there ismuch less consensus regarding the most effective method of hand drying in terms of hand hygiene inhealth care settings.

1.4 Objectives of the study

The objective of this project is to construct a machine that will automatically dries up the wetness of a hand, when those hand are placed before it.

1.5 Significance of the study

Hand dryers have been popular and more economical in many homes, hand dryers can cut cost by 99.5% (for example a company may spend 500,000 per year on paper towels, where as the hand dryer expenditure would be as low as 30,000 per year. This would vary due to cost of towels .Also, due to the reduction in liter and waste in comparison with towels, which cannot be recycled, hand dryers are also claimed to be better for the environment .
Hand dryers are more hygienic compared to a towel. It does not require close contact before it commences its operation neither does it require washing after use.

1.6 Scope of the study

The automatic hand drier is operated automatically using a sensor called light dependent resistor (LDR). The LDR operates whenever it senses darkness or shadow in the absence of light. The resistance of the LDR is reduced whenever it experiences darkness thereby allowing the flow of electric current through it. Thus, this project is limited to a light dependent resistor, there are other type of sensor used in the modification of an automatic hand drier.

Chapter Five

5.0 Conclusion And Recommendation

5.1 Conclusion

The task of construction of the automatic hand drier was challenging and interesting.

It can be seen that the described circuit (Automatic hand drier) will operate when a user places his hands in the direction zone and remains there for a short moment, but the drier will not operate for an overly long period of time, which would waste power. Neither would the drier operate in response to momentary or passing signals, but it will shut off if a user momentarily removes his hands from detection zone. The objective of this project work was actually realized.

5.2 Recommendation

The automatic hand drier is recommended for us in academic environments, offices, hotels, and eateries and residential home. This automatic hand drier is recommended for use in Rector’s office.It is also recommended that more research should be carried out on the design and construction of the hand drier so that a reduced size can be achieved.

How To Get The Complete Material For Automatic Hand Dryer With Temperature Display

Project Material Download

3,000 Naira

The Complete Material Will Be Sent to You in Just 2 Steps

Quick & Simple…

Step One Purchase

Make Payment (Through Transfer) of ₦3,000 to Any of the Account Below

Access Bank PlcAcc No: 0811003731
Samphina Academy
Current Account
Zenith BankAcc No: 1225513212
Samphina Academy
Current Account
PalmPay Main LogoAcc No: 8143831497
Samphina Academy
Digital Account

Or CLICK HERE To Pay With Debit Card

CLICK HERE To Purchase Material ($15)
Make Payment of 80 GHS to 0553978005 | Douglas Osabutey | MTN MoMo

Step Two Purchase

Send the Following Details on WhatsApp ( 08143831497) After Payment

  1. Payment Details
  2. Email Address 
  3. Automatic Hand Dryer With Temperature Display

The Complete Material Will Be Sent To Your Email Address After Receiving Your Details
T & C Apply

  Contact Our Help Desk

Samphina Academy

Samphina Academy is an Online Educational Resource Center that is aimed at providing students with quality information and materials to aid them in succeeding in their academic pursuit.