Relays & Solid State Relays

Relays & Solid State Relays

Whether you're building an Arduino automation project, designing a PCB circuit, or upgrading an industrial control system, the right relay makes all the difference. Our Relays & Solid State Relays collection offers a comprehensive range of switching solutions — from compact signal relays and optocoupler-isolated modules to high-current power relays and solid state relay (SSR) components. Available in a wide selection of coil voltages (3V, 5V, 12V, 24V, and 230V), current ratings (up to 63A), and form factors (DIP, SMD, PCB-mount, and panel-mount), you'll find the perfect relay for hobby electronics, home automation, automotive applications, and beyond. Stock up with our convenient multi-packs and assortment kits to keep your projects moving forward.

Featured Products

Why Choose Our Relays & Solid State Relays?

  • Wide Voltage & Current Range: From low-power 3V signal relays to 63A mains protection modules, we have a relay for every application.
  • Optocoupler & SSR Isolation: Protect your microcontrollers and sensitive logic circuits with optocoupler-isolated modules and solid state relay designs.
  • Arduino & MCU Compatible: Most modules are plug-and-play with Arduino, Raspberry Pi, ESP32, and other popular platforms.
  • Bulk & Assortment Packs: Save more with 5-packs, 10-packs, and 100-piece lots — ideal for workshops, labs, and restocking.
  • Multiple Form Factors: Choose from DIP, SMD, PCB-mount, panel-mount, and wireless RF modules to suit any build style.

Learn more: EPA guidance on lithium-ion battery handling

Frequently Asked Questions

Q: What is the difference between a mechanical relay and a solid state relay (SSR)?

A: A mechanical relay uses physical contacts to switch circuits, making it suitable for a wide range of loads but generating slight noise and wear over time. A solid state relay (SSR), such as the G3MB-202P SSR pack, uses semiconductor components for silent, high-speed switching with no moving parts, offering longer service life and faster response times — ideal for high-frequency switching applications.

Q: What voltage relay module do I need for an Arduino project?

A: Most Arduino boards operate at 5V logic, so a 5V coil relay module is the most common choice. However, if you're using a 3.3V board (such as ESP32 or Raspberry Pi), look for modules like the 1-Channel Relay Module with Dual Optocoupler Isolation, which supports logic levels from 3.3V to 24V and protects your MCU from back-EMF spikes.

Q: What does optocoupler isolation mean in a relay module?

A: Optocoupler isolation means the control circuit (your microcontroller) and the load circuit (the device being switched) are electrically separated using an optocoupler (a light-based signal coupler). This protects your Arduino or other sensitive electronics from voltage spikes and noise generated by the switched load, greatly improving reliability and safety.

Q: Can I use these relays for home automation or smart home projects?

A: Yes! Modules like the 433MHz RF Relay Receiver Module and the 1-Channel DC 12V IR Remote Relay Switch Module are excellent for wireless home automation, allowing you to control lights, fans, and other appliances remotely without rewiring your home.

Q: Are bulk relay packs available for larger projects or restocking?

A: Absolutely. We offer several multi-pack options, including the 100Pcs DC Power Relay 5V 12V 24V 20A 5-Pin PCB Auto Relay for automotive and PCB applications, as well as 10-packs of signal relays and power relays — perfect for electronics workshops, educational labs, and production-level builds.

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  • ATDV-Y Dual Repeat Cycle Time Relay 220V – 10 Timing Ranges

    ATDV-Y Dual Repeat Cycle Time Relay 220V – 10 Timing Ranges

    Sale price  $46.09 Regular price $57.04
  • ASY-3D Digital Delay Timer Relay 8-Pin | 12V–220V Programmable

    ASY-3D Digital Delay Timer Relay 8-Pin | 12V–220V Programmable

    Sale price  $43.39 Regular price $53.66
  • AHC15A LCD Programmable Timer Relay Switch 12V–220V | 16A

    AHC15A LCD Programmable Timer Relay Switch 12V–220V | 16A

    Sale price  $41.60 Regular price $51.41
  • AH3-N 8-Pin Adjustable Time Delay Relay | Multi-Range Timer

    AH3-N 8-Pin Adjustable Time Delay Relay | Multi-Range Timer

    Sale price  $41.06 Regular price $50.74
  • AH3-DM Digital Time Relay Dual Mode LED Delay Timer 12–380V

    AH3-DM Digital Time Relay Dual Mode LED Delay Timer 12–380V

    Sale price  $27.64 Regular price $33.90
  • AFR-1 AC220V Liquid Level Controller Relay – Auto Water Switch

    AFR-1 AC220V Liquid Level Controller Relay – Auto Water Switch

    Sale price  $51.32 Regular price $63.60
  • AC Solid State Relay 10A 25A 40A Single Phase | 24–480VAC

    AC Solid State Relay 10A 25A 40A Single Phase | 24–480VAC

    Sale price  $20.04 Regular price $24.38
  • 5V Bistable Latching Relay DPDT 2A 30VDC – HFD2/005-S-L2-D

    5V Bistable Latching Relay DPDT 2A 30VDC – HFD2/005-S-L2-D

    Sale price  $12.24 Regular price $14.59
  • 5V 12V Relay Module Optocoupler Isolation – 1 Channel Board

    5V 12V Relay Module Optocoupler Isolation – 1 Channel Board

    Sale price  $5.96 Regular price $6.71
  • 50pcs SMD Relay Set – NDFF Series Surface Mount Components

    50pcs SMD Relay Set – NDFF Series Surface Mount Components

    Sale price  $83.40 Regular price $103.84
  • 5-Pack G2RL-1 PCB Relay 5V 12V 24VDC – General Purpose

    5-Pack G2RL-1 PCB Relay 5V 12V 24VDC – General Purpose

    Sale price  $22.38 Regular price $27.30
  • 433MHz RF Relay Receiver Module – 1CH Wireless Light Switch

    433MHz RF Relay Receiver Module – 1CH Wireless Light Switch

    Sale price  $13.23 Regular price $15.83
  • 4-Channel MOSFET PWM Switch Controller Board DC 5V–27V

    4-Channel MOSFET PWM Switch Controller Board DC 5V–27V

    Sale price  $13.91 Regular price $16.69
  • 4-Channel MOSFET Driver Board PWM 3-20V to 27V DC 10A Module

    4-Channel MOSFET Driver Board PWM 3-20V to 27V DC 10A Module

    Sale price  $17.23 Regular price $20.85
  • 230V 40A/63A Adjustable Voltage & Current Protection Relay

    230V 40A/63A Adjustable Voltage & Current Protection Relay

    Sale price  $12.66 Regular price $15.11
  • 2-Channel Automatic Power Switch Module 220V 10A Dual Input

    2-Channel Automatic Power Switch Module 220V 10A Dual Input

    Sale price  $23.12 Regular price $28.24
  • 10pcs Mixed General Purpose IC Chip Assortment – Relay ICs

    10pcs Mixed General Purpose IC Chip Assortment – Relay ICs

    Sale price  $26.53 Regular price $32.51
  • 10pcs HFD4 SMD DIP Signal Relay – 3V 5V 12V 24V Variants

    10pcs HFD4 SMD DIP Signal Relay – 3V 5V 12V 24V Variants

    Sale price  $40.46 Regular price $49.99
  • 10PCS G3MB-202P SSR & Schottky Diode IC Component Pack

    10PCS G3MB-202P SSR & Schottky Diode IC Component Pack

    Sale price  $14.39 Regular price $17.29
  • 100Pcs DC Power Relay 5V 12V 24V 20A 5-Pin PCB Auto Relay

    100Pcs DC Power Relay 5V 12V 24V 20A 5-Pin PCB Auto Relay

    Sale price  $113.93 Regular price $142.13
  • 10-Pack SMIH DC Signal Relay – 5V 12V 24V SL-A & SL-C

    10-Pack SMIH DC Signal Relay – 5V 12V 24V SL-A & SL-C

    Sale price  $36.76 Regular price $45.34
  • 10-Pack RT314012/RT314024 16A 250VAC 8-Pin Power Relay 12V 24V

    10-Pack RT314012/RT314024 16A 250VAC 8-Pin Power Relay 12V 24V

    Sale price  $59.54 Regular price $73.91
  • 1-Channel Relay Module 3.3V–24V Dual Optocoupler Isolation

    1-Channel Relay Module 3.3V–24V Dual Optocoupler Isolation

    Sale price  $11.04 Regular price $13.09
  • 1-Channel DC 12V IR Remote Relay Switch Module for Arduino

    1-Channel DC 12V IR Remote Relay Switch Module for Arduino

    Sale price  $10.80 Regular price $12.79