5V 8-Channel Relay Module with Optocoupler
High-Power Switching Module for Microcontroller Control
This 8channel relay module enables a microcontroller to independently control up to eight highpower devices such as lights, motors, and solenoids [citation:2][citation:3]. Each relay provides complete electrical isolation between the lowvoltage control circuit and the highpower load circuit, protecting your microcontroller [citation:1][citation:3].
Controls 8 Independent AC/DC Loads - Each relay can switch up to 250V AC @ 10A or 30V DC @ 10A [citation:2][citation:4]
Optocoupler Isolation Provides excellent antiinterference capability and protects the control circuit [citation:4][citation:8]
Operating voltage is 5V DC with each channel requiring 15-20mA drive current [citation:1][citation:12]
Total module operating current is approximately 480mA, so use an external 5V power supply [citation:1][citation:12]
The module is active LOW by default (LOW signal activates the relay) [citation:2][citation:3][citation:4]
Technical Specifications
| Parameter | Value |
|---|
| Operating Voltage | 5V DC |
| Channels | 8 |
| Maximum Load (AC) | 250V @ 10A |
| Maximum Load (DC) | 30V @ 10A |
| Isolation | Optocoupler [citation:2][citation:3] |
| Indicator LEDs | 8 (one per channel) [citation:2][citation:3] |
| Dimensions | ~137mm x 56mm [citation:1][citation:2] |
= Pin Configuration =
*Input Pins (Control Side):*
- VCC: 5V DC power supply
- GND: Ground connection
- IN1 - IN8: Control pins for each relay (active LOW)
For most modules, a LOW signal (0V) on INx activates the relay [citation:2][citation:3][citation:4]
*Output Pins (Relay Side)* [citation:2][citation:4]:
- COM: Common terminal (connect to load power source)
- NO (Normally Open): Load connects here to turn ON when relay is activated
- NC (Normally Closed): Load connects here to turn OFF when relay is activated
Applications
- Home automation (lights, fans, appliances) [citation:2][citation:3]
- Industrial control systems [citation:2][citation:3]
- Robotics and IoT projects [citation:2][citation:3]
- Security systems (alarms, locks) [citation:3]
Versatile Control Manage multiple highpower devices simultaneously
Wide Compatibility - Works with Arduino, ESP32, Raspberry Pi, and other microcontrollers [citation:3][citation:4][citation:5]
√ Each relay has independent indicator LED for status monitoring [citation:1][citation:2][citation:3]
√ Standard screw terminals for easy load wiring [citation:8]
√ Includes flyback diodes for protection against voltage spikes [citation:3]
Troubleshooting
Relays not activating:
- Ensure the module is powered with a stable 5V DC supply [citation:3][citation:12]
- Check signal logic: module is active LOW by default [citation:3]
Load not switching:
- Verify wiring to NO/NC and COM terminals [citation:3]
- Ensure load does not exceed 250V AC @ 10A or 30V DC @ 10A rating [citation:2]
Arduino resets or module behaves erratically:
- Use an external 5V power supply for the relay module; Arduino's 5V pin may not supply sufficient current [citation:3][citation:12]
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