Automatic Non-contact Hand Sanitizer Unit

Automatic Non-contact Hand Sanitizer Unit

Due to corona virus outbreak,many people started using hand sanitizers frequently and started social distancing to avoid getting infected.However it is inevitable that people are gathering in many public places daily.

Many stores/shops/supermarkets/business places/offices & other companies have used many methods to ensure their customers follow safety procedures like installing thermometers,sanitizer units for customer usage.

This simple project explains how to easily build an automatic non-contact hand sanitizer unit using simple electronic components.

The objective is to build a reusable liquid sanitizer container with sensor operated liquid ejection for using the sanitizer without touching it in anyway.

Since the unit is powered by 5V,an USB cable was used due to common usage of USB chargers.

The IR sensor outputs a 5V voltage level (High) when it is in normal operational condition.

When the IR sensor detects an objective(in this case,a hand) the sensor output becomes 0V(Low).

When the IR sensor outputs the 0V level,the PNP transistor acts as a closed switch and the pump motor operates.

When the IR sensor outputs the 5V level,the PNP transistor acts as a open switch and deactivates the pump motor.

The sensor range distance can be calibrated from the onboard potentiometer.

Note : When tested at outdoor conditions,the IR sensor output became unreliable in the sunlight.Hence this unit is for indoor use only(under room temperature)

Components & Tools

1 X TIP32C IC

1 X IR Sensor

1 X 1K Ohm Resistor

1 X Dot Board

1 X Motor Pump(5V DC)

1 XX USB Power Cable

Clear PVC Tubing(~30cm)

Silicone Sealant

Soldering Iron

Connecting Components

Resistor = 1K Ohm

TIP32C Base To IR Sensor Sig. Out

TIP32C Emitter To Power In (+5V)

TIP32C Collector To Pump Motor  (+)

Use a 22uF Capacitor in parallel with motor power supply(as shown in the PCB layout below)

PCB Layout

PCB 3D View

Container Configuration

Use a transparent container unit if possible.By doing so,the liquid level is visible to outside.

Circuit and motor pump is installed in the lower base and it has to be completely sealed off from rest of the container.

There are two PVC tubes connected to the pump motor.One tube is connected to pump liquid input side and other tube is connected to pump output.

IR sensor is isolated from rest of the circuit and it is installed in the upper level of the container.IR sensor and wires connected to it must be also sealed off.That means no liquid contact with the IR sensor and wires.(use piece of PVC tube as a cover to wires)

Do not raise the output PVC tube too high,the 5V pump motor is not powerful enough to raise liquid to a higher level without having a higher time delay.(In this project, the output liquid is raised to a height of 20cm)

Use a suitable nozzle arrangement to control the liquid flow.Sanitizer liquid is easily vaporizable.So it should not exposed to outer surrounding at normal condition.

Once the container is empty, simply remove the upper cap and refill.

Safety First !

Always Connect the power supply if you are absolutely sure that the components are connected correctly without changing polarity and short circuited the wiring.

Even if it seems nothing is wrong : DOUBLE CHECK EVERYTHING !!

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