single transistor mosquito
Build a simple mosquito repeller using a single BC547C transistor. Generates high-frequency sound to repel mosquitoes, perfect for DIY electronics projects.

single transistor mosquito circuit:
The mosquito repeller is a single-transistor mosquito repeller with BC547C that produces high-frequency sound to repel mosquitoes. The BC547C is used as an oscillator with a frequency of ultrasonic waves to scare the mosquitoes safely.
high-frequency mosquito sound:
Single Transistor Mosquito Repeller with BC547C is a really easy and efficient DIY electronics project that would repel mosquitoes with high-frequency sound. The BC547C transistor is used as an oscillator to produce ultrasonic frequencies, which are uncomfortable to mosquitoes but an inhuman sound. This project will suit hobbyists, students, and beginners in electronics. The circuit runs on a low-voltage DC power supply, thereby being safe to be used in the home. The ultrasonic sound is emitted by a piezo buzzer or a small speaker. The frequency of oscillation is the value of the components, i.e., the resistors and capacitors, which gives the possibility to tune to the best. The design is focused on being simple, stable, and cost-effective, and, therefore, is a good choice in educational electronics experiments or a homemade mosquito repellent.
⚡ Work & Installation (Input → Output):
- Power Supply → 3–9V DC low-voltage supply.
- BC547C Transistor → Acts as an oscillator generating high-frequency signal.
- Frequency Components → Resistors and capacitors set ultrasonic frequency.
- Output Device → Piezo buzzer or small speaker emits high-frequency sound.
- Installation → Assemble components on breadboard or PCB, connect power and speaker, and test for ultrasonic output. Place the repeller in mosquito-prone areas.
Testing & Final Adjustments:
When it is assembled, turn the circuit on and ensure that the buzzer generates high-frequency sound. Change resistors or capacitors to make an optimal frequency selection to keep the mosquito repelled. Make sure that the BC547C transistor is in the correct orientation. The circuit should be tested in a safe place where pets are not present because some animals are sensitive to ultrasonic sound. Ensure that it has not overheated and that it is still operating. Use PCB or enclosure components with a securing material to ensure that they do not get damaged by moisture. The right testing will guarantee the effective and safe working of the mosquito repellents and is a good DIY project in the small indoor areas.
Frequently Asked Questions - single transistor mosquito:
What is BC547C?
A general-purpose NPN transistor used as an oscillator in this circuit.
Voltage required?
Typically 3–9V DC low-voltage supply.
Output type?
High-frequency sound emitted via a piezo buzzer or speaker.
Is it safe for humans?
Yes, the ultrasonic frequency is inaudible and safe for humans.
Applications?
Indoor mosquito repellent, educational electronics project.
Can frequency be adjusted?
Yes, by changing resistor and capacitor values.
Beginner-friendly?
Yes, simple components and low-voltage operation.
Continuous operation safe?
Yes, with proper heat management.
Can it affect pets?
Some pets may hear ultrasonic sound, so test carefully.
PCB needed?
Optional, breadboard works for prototype or learning purpose.
Related Posts

Temperature Sensor Fan Controller Circuit
Automatically control a 12V/24V fan using a temperature sensor (LM35 / DS18B20 / NTC). Comparator or MCU drives a MOSFET/relay to switch fan based on set temperature threshold.

Fire Alarm System Project
Design a simple fire alarm system using BC547 transistor. Detect smoke or heat and trigger buzzer or LED for early fire warning in DIY projects.

5v Regulator 7805 Upgrade to 10a
Learn how to upgrade a 7805 voltage regulator to deliver up to 10A output using pass transistors or buck converters with safe installation steps.

BC557 Transistor Project
Explore BC557 transistor projects for DIY electronics. Build amplifiers, switches, or LED control circuits using this PNP transistor in simple setups.

12V to 5V Converter
Learn how a 5V voltage regulator circuit works, circuit diagram, applications, and how to regulate 12V or higher voltage down to stable 5V DC for electronics.

Touch on-off Switch Circuit
Simple NE555-based touch on-off switch circuit for controlling LEDs and small loads with a single touch, ideal for DIY electronics projects.





