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Automatic Hand Sanitizer Dispenser | Benefits | Application

Automatic Hand Sanitizer Dispenser


Corona Virus is wreaking havoc in the world. Most of the country in the world is suffering from the Corona Virus. WHO has already declared it as a Pandemic disease and many cities are in lockdown situations and changed our lifestyle. In this present scenario of the global outbreak, it is instructed by WHO (world health organization) to maintain Healthy Hand Wash and Sanitation Habits, but the key problem is the way we do it, this is by physical touch. Touching hand sanitizers with infected hands can spread the virus to the next person. In this content, we will build an automatic hand sanitizer dispenser that uses IR sensors to detect the presence of a hand and activates a pump to pour the liquid on the hand.

You can find various Arduino automated liquid dispensers circulating the web. But our motive is to keep it simple and cheap so that anyone can replicate it. Possibly the easiest solution for this purpose is to use a simple transistor with an IR proximity sensor, which would also drastically reduce the costs. Obviously, the absence of a microcontroller removes control over spilling, but using a smaller nozzle would physically maintain the flow of liquid.

Flow Chart

automatic hand sanitizer dispenser



The Demand for hand sanitizers has surged as the Corona Virus broke out and spread around the world. The gel hand sanitizers are generally used by squirting the sanitizer liquid when one presses a pump with one’s hand. It causes many people to come into contact with the pump handle, which raises the risk of viral transmission. Pressing the pump handle is boring, and many pass by without disinfecting their hands. Moreover, every person presses the pump handle separately, making it difficult to predict the amount of use and to manage refills and replacements. For this reason, the actual use of hand sanitizers is attenuate, which not helping to prevent the spread of the virus.

Many hand sanitizers on market are automatically pumped. Because sanitizer containers and pump devices are designed to be suitable only between products produced by the same manufacturer, consumers must also repurchase the container for the liquid if they replace the hand sanitizer. It is not economical and it has a negative influence on the environment by increasing waste emissions. Moreover, some users think that it is a hassle to buy a hand sanitizer-containing device compatible again, so they pour other hand sanitizers into previously used containers and reuse them. However, sanitizers that come directly into contact with the human body are classified as medicines or non-medical products, and they are safest to use in actual containers.

In this context, the design of an automatic hand sanitizer system compatible with different sanitizer containers is presented. 

Working Principle

My project is working for auto hand sanitizing and also work for indicating water level.

Working Of Hand Sanitizing

The schematic is simple and easy to understand. I used an IR sensor, relay module, circulating pump for the circuit. When the IR sensor faced with any object then it gives output to the relay module energized and trip the coil and close the circuit. So ready to start the motor for circulating water or sanitizer.

automatic hand sanitizer dispenser

Working of water level Indicator

The connections and the arrangements are formed as shown in the figure below. The 9v supplied to water using a metal contact.  In this configuration, all the transistors are working as a switch. When the water touches the metal contact in which the base of the transistors is connected, a small current flows and turns on the transistor. When a transistor turns on, the LED connected with it glows.

In this way, LEDs will be turned on depending upon the level of water. Using a relay we can also control the level of water.

automatic hand sanitizer dispenser

Circuit Diagram

automatic hand sanitizer dispenser

                                                               Figure:- Circuit diagram of automatic hand sanitizer

automatic hand sanitizer dispenser

Figure:- Circuit diagram of water level indicator

Objectives of the Project

Hand sanitizers are generally applied by squirting the sanitizer liquid when one presses a pump with one’s hand. It causes many people to come into contact with the pump handle, which increases the risk of viral transmission. For this, we need automatic hand sanitizer. In my project, I build a simple automatic hand sanitizer by using an IR sensor. It is very simple construction and cost-effective. It is very much familiar to people.


Components For Hand Sanitizer Dispenser

  1. IR Sensor
  2. Relay Module
  3. DC Water Pump
  4. 5v Power Supply
  5. Pipe

Components For Water Level Indicator

  1. BC 547 Transistor
  2. LED
  3. Resistor

Other Instruments

  1. Jumper Wair 
  2. Glue Gun
  3. LED

IR sensor


An infrared sensor emits for sense some aspects of the surroundings. An infrared sensor can measure the heat of an object and detects its motion. These types of sensors measure only infrared radiation, rather than emitting it which is called a passive IR sensor. Generally, in the infrared spectrum, all the objects radiate some form of thermal radiation.

These types of radiations are not visible to our eyes, which can be detected by an infrared sensor. The emitter is simply an IR LED (Light Emitting Diode) and the detector is simply an IR photodiode that is sensitive to infrared light of the same wavelength as that emitted by the IR LED. When infrared light falls on the photodiode, the resistances and the output voltages will change in proportion to the magnitude of the IR light received.

automatic hand sanitizer dispenser

Working Principle

The working principle of an infrared sensor is the same as the object detector sensor. This sensor includes an infrared LED & an IR Photodiode, so combining these two can be formed as a photo-coupler otherwise opt coupler. The physics laws used in this infrared sensor are Planks radiation, Stephan Boltzmann & Weins displacement.

IR LED is one kind of transmitter that emits IR radiation. This LED looks the same as a standard LED and the radiation which is generated by this is not visible to the human eye. Infrared receivers detect the radiation using an infrared transmitter. These infrared receivers are available in photodiode form. IR Photodiodes are dissimilar as compared with normal photodiodes because they detect simply IR radiation. Various kinds of infrared receivers mainly exist depending on the voltage, wavelength, package, etc.

Once it used as the combination of an infrared transmitter & receiver, then the receiver’s wavelength must equal the transmitter. Here, the transmitter is an infrared LED whereas the receiver is an infrared photodiode. The infrared photodiode is reactionary to the infrared light that is generated through an infrared LED. The resistance of the photodiode & the change in output voltage is in ratio to the infrared light obtained. This is the IR sensor’s fundamental working principle.

IR Sensor Circuit Diagram

An infrared sensor circuit is the primary and popular sensor module in an electronic device. This sensor is similar to human’s visionary senses, which can be used to detect obstacles and it is one of the common applications in real-time. This circuit comprises the following components.

  1. LM358 IC2 IR transmitter and receiver pair
  2. Resistors of the range of kilo-ohms.
  3. Variable resistors.
  4. LED (Light Emitting Diode).

automatic hand sanitizer dispenser


In this project, the transmitter section has an infrared sensor,  transmits continuous infrared rays to be received by an IR receiver module. The output terminal of the infrared of the receiver varies depending on its receiving of infrared rays. Whereas this variation cannot be analyzed as such, therefore this output can be fed to a comparator circuit. An operational amplifier (op-amp) LM 339 is used as a comparator.

The potential at the inverting input goes higher than that non-inverting input of the comparator IC (LM339) when the infrared receiver does not receive a signal. The LED does not glow when the output of the comparator goes low, but. The potential at the inverting input goes low when the IR receiver module receives a signal. Thus the output of the comparator LM 339 turns high and the LED starts glowing.

Resistor R1 (100 ), R2 (10k ), and R3 (330) are used to confirm that a minimum of 10 mA current passes through the IR LED Devices like Photodiode and normal LEDs respectively. To adjust the output terminals resistor VR2 (preset=5k) is used. To set the sensitivity of the circuit diagram resistor VR1 (preset=10k) is used. Read more about IR sensors.

Circuit Working

When the infrared LED is detected, then the reflected light from the thing activates a small current that will supply throughout the IR LED detector. This will activate the NPN transistor & the PNP; then the LED will switch ON. This circuit is applicable for making several projects like automatic lamps to activate once a person approaches close to the light.


The advantages of IR sensor include the following

  • It uses less power
  • Motion detection is possible in the presence or absence of light approximately with equal reliability.
  • They do not need a connection with the object for detection
  • There is no data leakage 
  • These sensors are not affected by corrosion & oxidation 
  • Noise immunity is very strong


The disadvantages of IR sensor include the following

  • Line of sight is required
  • Range is limited
  • These can be affected by fog, rain, dust, etc
  • Less data transmission rate

IR Sensor Applications

Depending on the applications IR sensors are classified into different types. Some applications of different types of sensors. The speed detection sensor is used for synchronizing the speed of multiple motors. The temperature measuring sensor is used for industrial temperature control. PIR motion sensor is used for an automatic door opening system and the Ultrasonic sensor is used for distance measurement.

IR sensors are used in various Sensor based projects and also in various electronic devices which measure the temperature.

Mini Submarine Pump


Micro DC 3 to 6V Micro Submersible Pump Mini water pump For Garden Mini water circulation System DIY project. This is a low-cost and small-size Submersible Pump that can be operated from a 3 to 6V power supply. It can take up to 120 liters/hour with a very low current consumption of 220mA. Just connect the pipe to the motor outlet, submerge it in water, and power it. Confirm every time that the water level is higher than the motor. A dry run can damage the motor due to heating and it will also produce noise.

automatic hand sanitizer dispenser


                                                                                     Figure:- Mini Submarine Pump


  • Operating Voltage : 3 ~ 6V
  • Operating Current : 130 ~ 220mA
  • Flow Rate : 80 ~ 120 L/H
  • Maximum Lift : 40 ~ 110 mm
  • Continuous Working Life: 500 hours
  • Driving Mode: DC, Magnetic Driving

Relay Module


 A relay module is an electrical switch operated by an electromagnet. A separate low-power signal from the microcontroller activates the electromagnet. The electromagnet pulls on or off an electrical circuit when it activated. Relays are used where it is essential to control a circuit by an independent low-power signal, or where several circuits must be controlled by one signal. Relays were first used as signal repeaters in long-distance telegraph circuits: they refresh the signal coming in from one circuit by transmitting it on another circuit. In telephone exchanges and early computers to perform logical operations, Relays were used extensively.automatic hand sanitizer dispenser

 Figure:- Relay Module

Principle of Relay Module

The signal light will glow up and the opt coupler 817c (it transforms electrical signals by light and can isolate input and output electrical signals) will conduct, and then the transistor will conduct, the relay coil will be electrified, and the open contact of the relay will be closed. When the signal port is at a high level, the normally closed contact of the relay will be closed. So now you can connect or disconnect the load by controlling the level of the control signal port.


Relays are used where it is essential to control a high power or high voltage circuit with a low power circuit, particularly when galvanic isolation is desirable. The first application s of the relay was in long telegraph lines, where the weak signal received at an intermediary station could control a contact, regenerating the signal for further transmission. High-voltage or current devices can be controlled with low voltage wiring and pilot switches. Operators can be diverse from the high voltage circuit. Low power devices like microprocessors can drive relays to control electrical loads moreover their direct drive capability. In an automobile, a relay starter allows the high current of the cranking motor to be controlled with small wiring and contacts in the ignition key.

The use of relays for the logical control of complicated switching systems like telephone exchanges was studied by Claude Shannon, who formalized the application of Boolean algebra to relay circuit designing in A Symbolic solution of Relay and Switching Circuits. Relays can redact the basic operations of Boolean combinatorial logic. For example, such as the boolean AND function is realized by connecting normally open relay contacts in series and the OR function by connecting normally open contacts in parallel. Inversion of a logical input can be done by a normally closed contact. Relays were used for the control of automatic systems for machine tools and production lines. The Ladder programming language is mostly used for designing relay logic networks.

BC 547 Transistor

The BC547 transistor is an NPN transistor. A small amount of current of the base terminal of this transistor will control the large current of the emitter and base terminals. The main function of this transistor is to amplify and switching. The maximum gain current of this transistor is 800Amp’

Bc547 Transistor Pin Configuration

automatic hand sanitizer dispenser

  1. Pin1 (Collector): This pin is denoted with the symbol ‘C’ and the flow of current will be through the collector terminal.
  2. Pin2 (Base): This pin controls the transistor biasing.
  3. Pin3 (Emitter): The current supplies out through emitter t
  4. A Transistor works as an amplifier while functions in the active region to amplify voltage, current, and power at different configurations. The amplifier circuit uses three configurations which are the following.
  5. Common emitter (CE) amplifier
  6. Common collector (CC) amplifier
  7. Common base (CB) amplifier


Applications of BC547 transistor include the following.

  1. This BC547 transistor is used in general-purpose, widely used and it is used as an alternative and a substitute to different kinds of transistors. Thus, it can use in different electronic circuits
  2. The absolute transition frequency of BC547 is 300MHz so that it will perform well within RF circuits.
  3. Amplification of current
  4. Audio Amplifiers
  5. Switching Loads < 100mA
  6. Transistor Darlington Pairs
  7. Drivers like a LEDdriver, Relay Driver, etc.
  8. Amplifiers like Audio, signal, etc.
  9. Darlington pair
  10. Quick switching
  11. PWM (Pulse Width Modulation)

Jumper Wire

jump wire (also known as jumper wire, or jumper) is an electrical wire, in a cable, with a connector or pin at every end (or sometimes without them – simply “tinned”), which is usually used to interconnect the components of a breadboard or other prototype or test circuit, internally or with other equipment or components, without soldering. Individual jump wires are connected by inserting their “end connectors” into the slots provided in a breadboard, the header connector of a circuit board, or a piece of test equipment.

automatic hand sanitizer dispenser

Glue Gun

The gun uses a continuous-duty heating component to melt the plastic glue, which the user pushes through the gun either with a mechanical trigger mechanism on the gun or with direct finger pressure. … The glue is tacky when hot, and solidifies in a few seconds to one minute For commercial or businesses, household, hobby, and craft applications, inexpensive glue guns, and glue sticks are used for parts assembly, repairs, and bonding different materials. Variable heat glue guns enable proper control of viscosity and set times.

automatic hand sanitizer dispenser

LED [Light Emitting Diode]

A light-emitting diode (LED) is a semiconductor diode light source that emits light when current flows within it. Electrons in the semiconductor recombine with electron holes and releasing energy in the photon’s form. The color of the light is determined by the energy needed for electrons to cross the bandgap of the semiconductor. White light is acquired by using multiple semiconductors or a layer of light-emitting phosphor on the semiconductor device.

automatic hand sanitizer dispenser


  1. LED uses fall into four major categories:
  1. Visual signals where the light goes more or less directly from the source to the human eye, to carry a message or meaning
  2. Illumination where light is reflected from other objects to give visual response of these objects
  3. Measuring and interacting with processes no involving human vision


resistor is a passive electrical element that implements electrical resistance as a circuit element. In electronic circuits, resistors are used for reducing current flow, adjust signal levels, divide voltages, bias active elements, and terminate transmission lines, etc. High-power resistors can dissipate many watts of power as heat, may be used as part of motor controls, in power distribution systems, or as test loads for generators. Fixed resistors have resistances that only change a little with temperature, time, or operating voltage. Variable resistors are used to adjust circuit elements (such as volume control or a lamp dimmer), or as sensing devices for heat, light, humidity, force, or chemical activity.

Resistors are normal elements of electrical networks and electronic circuits and are universal in electronic equipment. Practical resistors as discrete components can be composed of different compounds and forms. Resistors are also implemented into integrated circuits.

The function of a resistor is specified by its resistance: common resistors are manufactured over a range of more than nine orders of magnitude. The nominal value of the resistance falls within the producing tolerance, indicated on the component.

automatic hand sanitizer dispenser

This project, there used three types of resistors. Their values are 100,220,460 ohms.


Cardboard is a generic term for heavy-duty paper-based products having a large thickness and superior stability or other specific mechanical attributes to paper; such as foldability, rigidity, and impact resistance. The construction can range from a thick sheet-like paperboard to corrugated fiberboard which is made of many corrugated and flat layers.

Despite widespread common use in English and French, the term cardboard is dissipation in commerce and industry as not adequately defining a specific product. Material producers, container manufacturers, packaging engineers, and standards organizations, use more specific nomenclature


In our project, I used a normal water pipe. The pipe connects to the Motor. Circulating liquid sanitizer to the output through the pipe by the pressure of the pump.

automatic hand sanitizer dispenser


An automatic hand sanitizer dispenser machine designed and developed. The machine is wall mount at the entrance gates of society, schools, colleges, or any commercial building. If a hand static in front of the IR sensor then it can always spray. It is a limitation of my project which is not effective in optimizing the use of liquid sanitizer. The machine is tested for 2hour operation for more than 2 days and is working fine. It helped to reduce the contact for getting sanitizer and also reduce manpower employed to spray sanitizer with a spray bottle. The power consumption is very low. For each spray the maximum current consumption is 500 mA at 5 V. It consumes 2.5W if run continuously for 1 hour. The control circuit is small in size and low cost as compared to accessible controllers. The power consumption is low and the system can help to achieve a contactless sanitizer dispenser. It reduces the chance of community transmission of the virus.

Benefits Of The Project


Moreover, a more sterile environment is made by the improvement of the automatic sanitizer dispenser. By using the pump, we will leave behind a diversity of bacterial colonies. Then they will interbreed and leads to a more resistant strain of bacteria which can re-contaminate various hands and would not be completely eliminated by the anti-bacterial soap or sanitizer. Wider spectra or higher levels of resistance in the present colonies are due to interaction or complementation between the resistance genes. The bacterial transmission will be wiped out once we stop using and touching the pump.

Preset increments

This device will only serve a set amount per motion activation. A specified amount to be dispensed can be set to a highly efficient quantity in which waste will be minimum.


Besides hand sanitizer, the dispenser’s structure also works for other liquids: soap, lotion, laundry detergent, etc. The wide range of possibilities widens the use of the dispenser to various locations other than the bathroom

Application Of The Project


  • Public place
  • Hospital
  • School & college
  • Industries
  • Office
  • Factory and so on.


The automatic hand sanitizer dispenser device proposed in this paper is ultimately expected to contribute to contactless hand disinfection in public places and virus infection prevention.It is economical and eco-friendly by decreasing waste emissions. At present time the world needs this product. It is very demandable for smart and cost-effective devices. But If a hand static in front of the IR sensor then it can always spray. It is a limitation of my project which is not effective in optimizing the use of liquid sanitizer. In the future, I improve this project by using Arduino, which improve the limitation of my project.






Automatic Hand Sanitizer Dispenser | Benefits | Application
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Automatic Hand Sanitizer Dispenser | Benefits | Application
You can find various Arduino automated liquid dispensers circulating the web. But our motive is to keep it simple and cheap so that anyone can replicate it. Possibly the easiest solution for this purpose is to use a simple transistor with an IR proximity sensor,
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