10-Pack 3-Pin Limit Switch 0-24V COM NC NO Mechanical Touch Sensor

10-Pack Mini Limit Switch — 3-Pin Mechanical Touch Sensor for DIY Electronics

Get reliable, precise circuit switching in your next DIY build with this set of 10 small limit switches. Each switch features three clearly labeled pins — COM (Common), NC (Normally Closed), and NO (Normally Open) — giving you full flexibility to design momentary-contact trigger circuits for robots, automation projects, model trains, conveyor systems, and more.

Compatible with a wide 0–24V voltage range, these compact plastic-bodied switches are an essential stock-up for hobbyists, makers, and electronics enthusiasts working with Arduino, Raspberry Pi, or any custom microcontroller circuit.

Key Features

• 3-Pin Configuration: COM, NC, and NO terminals for versatile wiring options
• Wide Voltage Range: Supports 0–24V DC/AC (low voltage: below 50V AC or 75V DC)
• Mechanical Trigger: Metal lever actuator provides tactile, reliable actuation every time
• Compact & Lightweight: Small form factor fits easily into tight PCB layouts and robot chassis
• Durable Plastic Housing: Built to withstand repeated triggering in DIY and prototyping environments
• Pack of 10: Great value — always have spares on hand for multiple projects

How It Works

The limit switch changes the circuit's closed state when its metal lever is pressed:

1. The three pins are labeled COM (common terminal), NC (normally closed), and NO (normally open).
2. Connect Pin A to the positive terminal of Circuit A, Pin B to the positive terminal of Circuit B, and the COM pin to the shared negative (ground) terminal.
3. In the default (unpressed) state, Circuit A is closed and Circuit B is open. When the lever is pressed, Circuit A opens and Circuit B closes — instantly toggling your circuit's state.

Typical Applications

• DIY robot collision detection & obstacle avoidance
• 3D printer end-stop / homing switches
• CNC machine axis limit detection
• Model train track control
• Automated conveyor or door-open sensing
• General Arduino / Raspberry Pi electronics projects

Specifications

Note: Due to screen color differences, the actual item color may vary slightly from product images. Please allow 1–10 mm variance due to manual measurement.

For guidance on safe working practices with low-voltage electronic components, visit OSHA Electrical Safety Resources.

Frequently Asked Questions

Q: What is the difference between the NC and NO terminals on a limit switch?

A: NC (Normally Closed) means the circuit between COM and NC is closed (conducting) when the switch lever is in its resting position and opens when the lever is pressed. NO (Normally Open) means the circuit between COM and NO is open in the resting position and closes when the lever is actuated. This lets you choose which logic behavior your project requires.

Q: Are these limit switches compatible with Arduino and Raspberry Pi projects?

A: Yes! These 3-pin mechanical limit switches work perfectly with Arduino, Raspberry Pi, and other microcontroller platforms. They operate within the 0–24V range, well within the safe logic levels used in most DIY electronics and robotics projects. Simply wire COM to ground, and connect either NC or NO to your digital input pin based on your desired logic.

Q: Can these switches be used as end-stop switches for a 3D printer or CNC machine?

A: Absolutely. These small limit switches are one of the most popular choices for 3D printer homing/end-stop functions and CNC axis limit detection. Their compact size, reliable mechanical trigger, and standard 3-pin layout make them a direct drop-in replacement for most common end-stop configurations.

Q: How many switches are included in this pack?

A: This listing includes 10 limit switches, giving you great value for stocking up on spares or outfitting multiple projects at once.