Earth Bondhon
Creators
Md Jony Islam Author
Md Jony Islam
CalculatorToolsProjectExpert
Reviewers
Małgorzata Koperska, MD Steven Wooding
Last updated: September 24, 2025

Single Push Button On-Off Switch Circuit Using IRFZ44N & BC557

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BC547 Transistor

BC547 Transistor

General-purpose NPN bipolar junction transistor (BJT)

IRFZ44N MOSFET

IRFZ44N MOSFET

N-channel power MOSFET, Vds 55V, Id 49A, Rds(on) ~0.032Ω, used for switching high-current loads efficiently in electronics projects and motor control circuits

Mini Push Button Switch

Mini Push Button Switch

A simple mechanical switch used to make or break a circuit when pressed. It returns to its original position once released. Commonly used in doorbells, calculators, reset buttons, and control panels.

1µF Capacitor

1µF Capacitor

Fixed value, non-polarized/polarized capacitor

10K Fixed Resistor 1/4W

10K Fixed Resistor 1/4W

A 10,000-ohm resistor rated for 0.25 watts

[10k-fixed-resistor-1/4w]
1m Fixed Resistor 1/4W

1M Fixed Resistor 1/4W

A 1 megaohm fixed resistor rated at 0.25 watts (¼W), used to limit current, drop voltage, or set biasing levels in electronic circuits.

*Please note: These are affiliate links. I may make a commission if you buy the components through these links. I would appreciate your support in this way!

Single Push Button on-off Switch

Build a simple single push button on-off switch using IRFZ44N MOSFET and BC557 transistor. Ideal for controlling DC loads in DIY electronics projects.

push button switch IRFZ44N:

The DC loads can be switched with the press of a single push-button on-off switch using IRFZ44N and BC557. The MOSFET is activated by the BC557, and the transfer of high current at constant speed is possible without mechanical relays.

DIY push button switch project:

Single Push Button On-Off Switch with IRFZ44N and BC557. This is a simple, small, and effective circuit that can be used to remotely control DC loads with just a push button. MOSFET BC557 transistor is employed to act on the gate of the IRFZ44N MOSFET, which provides on or off loading capabilities with high current carrying capability. The project is best suited to hobbyists, students, and DIY electronics projects that require a simple latching switch that does not use mechanical relays. As the button is pressed, the BC557 will activate the MOSFET and turn the load ON. Again, pressing the switches turns iis turned t off. The circuit is ideal for the regulation of LEDs, small motors, or other DC devices. The circuit is low voltage, can be assembled on a breadboard or a PCB, and has stable and reliable switching without mechanical wear.

⚡ Work & Installation (Input → Output):

  • Power Supply → DC supply matching load requirements.
  • Push Button → Single press toggles the switch state.
  • BC557 Transistor → Amplifies signal from push button to drive MOSFET gate.
  • IRFZ44N MOSFET → Switches the DC load ON or OFF.
  • Load → LEDs, motors, or other DC devices connected to MOSFET drain.
  • Installation → Assemble components on PCB or breadboard, connect power and load, and test toggle action.

Testing & Final Adjustments:

Upon assembling, the DC supply and push button should be pressed. Ensure that the load is switched ON and OFF after each press. Make sure that the orientation of the transistor BC557 is appropriate, such that it drives the MOSFET gate. Proper load control by connecting Check MOSFET (drain, gate, and source). In case switching is noisy, add a gate resistor or debounce the push button using a small capacitor. Test using various DC loads to ensure that the circuit is operating as expected. Stable and reliable operation without mechanical relays. Proper testing is available and is therefore suitable for hobby projects, LED control, and small DC motor applications. The mounted components are attached with safety, and the dissipation of heat to the MOSFET is sufficient in the event of control of higher currents.

Frequently Asked Questions - Single Push Button on-off Switch:

What is IRFZ44N?

It is an N-channel MOSFET used for switching DC loads.

What is BC557?

A PNP transistor used to drive the MOSFET gate.

Voltage requirement?

Matches the DC load voltage, typically 5–24V.

Can it handle high current?

Yes, depending on MOSFET rating and heatsinking.

Is it beginner-friendly?

Yes, simple components and easy assembly.

Applications?

LEDs, small motors, hobby electronics devices.

Can it replace mechanical relays?

Yes, provides silent and stable switching.

Do I need a heatsink?

Recommended for higher current loads on MOSFET.

Push button type?

Momentary push button is required for toggling.

Can it be mounted on PCB?

Yes, ideal for PCB or breadboard assembly.

Md Jony Islam

Md Jony Islam

CalculatorToolsProject

Founder of Earthbondhon.com

a free online tools website designed to make everyday and engineering-related calculations easier for students, professionals, and hobbyists. The site offers a wide range of basic calculators across key categories, including Electrical Calculators, Electronic Calculators, and Time & Date Calculators.