Switches & Relays

Switches & Relays for DIY Electronics & Beyond

Whether you're building an automation system, repairing a home appliance, prototyping an Arduino project, or upgrading your 3D printer, having the right switch or relay is essential. Our Switches & Relays collection brings together a comprehensive range of high-quality components — from robust relay modules and micro limit switches to rocker switches, DIP switches, and automatic transfer switches. Every component is sourced for reliability and performance, so your circuits do exactly what you intend, every time.

What's in This Collection?

Why Choose Our Switches & Relays?

  • ✅ Wide voltage & current range — from low-signal PCB switches to 100A power transfer switches
  • ✅ Optocoupler isolation on relay modules for safe MCU interfacing
  • ✅ Multi-packs available — great value for prototyping, stocking up, or classroom use
  • ✅ Arduino, Raspberry Pi & RAMPS 1.4 compatible components
  • ✅ Industry-standard form factors for easy drop-in replacements

Who Are These For?

Our switches and relays serve a wide audience: hobbyists and makers prototyping with microcontrollers, electronics engineers designing custom circuits, 3D printing enthusiasts building or repairing their machines, automotive DIYers managing circuit protection, and homeowners setting up smart or backup power solutions. No matter your project, you'll find the right switching component here.

Learn more: EPA guidance on lithium-ion battery handling

Frequently Asked Questions

Q: What is the difference between a relay module and a regular relay in DIY electronics projects?

A: A relay module combines a relay with supporting circuitry — such as a flyback diode, transistor driver, and optocoupler isolation — on a single PCB. This makes it much easier and safer to connect directly to a microcontroller like an Arduino, since the module handles the current amplification and voltage isolation needed to drive the relay coil. A bare relay, by contrast, requires you to build that supporting circuitry yourself.

Q: What are micro limit switches and where are they commonly used?

A: Micro limit switches are small, precise mechanical switches that are triggered by physical contact or movement. They are widely used as endstops in 3D printers and CNC machines to define the home position of each axis, in robotics to detect arm positions, in industrial machinery for safety cut-offs, and in appliances like microwaves and washing machines to detect door closure.

Q: How do I choose the right relay for my project — 5V, 12V, or 24V?

A: The coil voltage (5V, 12V, or 24V) refers to the voltage required to activate the relay, and should match your control circuit's supply voltage. For most Arduino and Raspberry Pi projects, a 5V relay module is ideal. For automotive or industrial applications, 12V or 24V relays are more common. The load contacts (e.g., 30A) must be rated at or above the current and voltage of the device you're controlling.

Q: Are rocker switches and limit switches suitable for outdoor or automotive use?

A: Many of our rocker switches are rated for both 250V AC and 125V AC applications and are suitable for panel-mounted use in vehicles, boats, and outdoor enclosures when properly sealed. For harsh environments, always check the IP rating of the specific switch. Our automotive-grade circuit protectors and transfer switches are designed with vehicle and generator applications in mind.

Q: Can I use these switches and relays with an Arduino or Raspberry Pi?

A: Yes! Our relay modules with optocoupler isolation are specifically designed for safe interfacing with 3.3V and 5V microcontrollers, including Arduino Uno, Mega, Nano, and Raspberry Pi. Micro limit switches with SPDT (Single Pole Double Throw) configurations are also directly compatible and widely used in RAMPS 1.4 and similar 3D printer control boards.
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