An automatic soap dispenser is like a robot for soap.
It has a special plan i.e circuit made of electric parts.
These parts include sensors like little eyes, a brain microcontroller and a pump like tiny muscles.
When the sensor sees your hand, the brain tells the pump to squirt out just the right amount of soap.
Circuit Working:
Parts List:
| Category | Item | Quantity | Notes |
|---|---|---|---|
| Resistors | 330Ω | 3 | 1/4 watt |
| 33k | 2 | 1/4 watt | |
| 1k | 2 | 1/4 watt | |
| Preset 10k | 1 | ||
| Semiconductors | IC LM358 | 1 | |
| Transistor TIP31 | 1 | ||
| Diodes | 1N4007 | 2 | |
| Sensors | IR Diode receiver | 1 | |
| LEDs | IR LED transmitter | 1 | |
| LED 5mm 20mA Red | 1 | ||
| LED 5mm 20mA Green | 1 | ||
| Other Components | Solenoid 5V | 1 | |
| ON/OFF Switch | 1 | ||
| Power Source | Battery 6V | 1 |
Automatic soap dispensers designed for liquid soap are readily available offering hands free operation to reduce the spread of germs.
Have you ever considered building one yourself?
Not only could it be more cost effective, but you could also gain valuable knowledge in the process.
Here is an idea for a touch free design that ensures clean and reliable soap dispensing.
This DIY project utilizes an infrared IR proximity sensor and a small solenoid to create a 6V DC powered automatic soap dispenser.
When the IR sensor detects a hand in close proximity it activates the solenoid driver which in turn energizes the solenoid to dispense soap.
Solenoids are ideal for creating linear motion useful for pushing or pulling levers.
By attaching a small rubber tube to the solenoid you can create a simple yet effective normally closed homemade valve.
In some cases, you may need to customize the solenoid arm with PVC parts to fit your rubber tube but this is not overly complex.
While the construction process is relatively basic careful attention should be paid to the mechanical layout.
It is recommended to house the circuit components in a high quality ABS case as an electronic module.
During assembly position the infrared sender LED1 and receiver PD1 at the front of the unit spaced at least 10mm apart and facing downwards.
Secure all interconnecting wires with cable ties.
Aside from the multi turn preset pot P1, there are no electrical adjustments required for this circuit.
Initially, the preset should be set to mid travel 5k+5k.
If necessary, you can adjust it to fine tune the sensitivity of the proximity detection.
Maximum rating of IC LM358
| Rating | Symbol | Value | Unit |
|---|---|---|---|
| Power Supply Voltages | Vdc | ||
| Single Supply | Vcc | 32 | Vdc |
| Split Supplies | Vcc, Vee | ±16 | Vdc |
| Input Differential Voltage Range | Vidr | ±32 | Vdc |
| Input Common Mode Voltage Range | Vicr | -0.3 to 32 | Vdc |
| Output Short Circuit Duration | tsc | Continuous | |
| Junction Temperature | Tj | 150 | °C |
| Thermal Resistance, Junction-to-Air | RθJA | °C/W | |
| Case 846A | 238 | °C/W | |
| Case 751 | 212 | °C/W | |
| Case 626 | 161 | °C/W | |
| Storage Temperature Range | Tstg | -65 to +150 | °C |
| Operating Ambient Temperature Range | TA | °C | |
| LM358, LM358A, LM358E | 0 to +70 | °C |
To build a Simple Automatic Soap Dispenser Circuit you need to follow the below mentioned steps:
Prepare the Components:
- Mount the infrared sender LED1 and receiver PD1 at the front of the unit facing downwards and spaced at least 10mm apart.
- Connect the solenoid to the rubber tube, ensuring it can squeeze the tube effectively.
Assemble the Circuit:
- Place the components on the circuit board following the schematic diagram.
- Connect the infrared sensor, solenoid and power source to the appropriate pins on the circuit board.
- Secure the components in place and solder the connections.
Install the Circuit:
- Place the circuit board in the ABS case, ensuring it fits securely.
- Secure the board in place using screws or adhesive.
Connect the Components:
- Connect the infrared sensor, solenoid and power source to the circuit board using wires.
- Use cable ties to secure the wires and prevent them from tangling.
Adjust the Preset Potentiometer P1:
- Set the preset potentiometer to mid travel 5k+5k.
- Test the proximity detection sensitivity by adjusting the potentiometer if necessary.
Final Assembly:
- Close the ABS case and secure it with screws.
- Ensure all components are properly connected and secured.
- Power on the dispenser and test the hands free operation.
- Adjust the sensitivity if needed by fine tuning the preset potentiometer.
Maintenance:
- Regularly check the dispenser for any loose connections or malfunctioning components.
- Replace the soap and rubber tube as needed.
Note:
- Please note that this is a basic guide, and you may need to customize the design based on your specific requirements and components available.
- Safety precautions should be followed when working with electrical components.
Conclusion:
An automatic soap dispenser circuit is a key component of a hands free and hygienic soap dispensing system.
By incorporating sensors, a control circuit and a dispenser mechanism this circuit enables the automatic and controlled release of soap or sanitizer when triggered by the presence of a hand or object.
Building such a circuit requires a good understanding of electronics and the ability to assemble and test the components effectively.
With the right knowledge and skills you can create your own automatic soap dispenser to enhance hygiene and convenience in various settings.