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 . Each relay provides complete electrical isolation between the lowvoltage control circuit and the highpower load circuit, protecting your microcontroller .
Controls 8 Independent AC/DC Loads - Each relay can switch up to 250V AC @ 10A or 30V DC @ 10A
Optocoupler Isolation Provides excellent antiinterference capability and protects the control circuit
Operating voltage is 5V DC with each channel requiring 15-20mA drive current
Total module operating current is approximately 480mA, so use an external 5V power supply
The module is active LOW by default (LOW signal activates the relay)
= Technical Specifications =
| Parameter | Value |
|---|
| Operating Voltage | 5V DC |
| Channels | 8 |
| Maximum Load (AC) | 250V @ 10A |
| Maximum Load (DC) | 30V @ 10A |
| Isolation | Optocoupler |
| Indicator LEDs | 8 (one per channel) |
| Dimensions | ~137mm x 56mm |
= 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
Output Pins (Relay Side) :
- 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)
- Industrial control systems
- Robotics and IoT projects
- Security systems (alarms, locks)
Versatile Control Manage multiple highpower devices simultaneously
Wide Compatibility - Works with Arduino, ESP32, Raspberry Pi, and other microcontrollers
√ Each relay has independent indicator LED for status monitoring
√ Standard screw terminals for easy load wiring
√ Includes flyback diodes for protection against voltage spikes
= Troubleshooting =
Relays not activating:
- Ensure the module is powered with a stable 5V DC supply
- Check signal logic: module is active LOW by default
Load not switching:
- Verify wiring to NO/NC and COM terminals
- Ensure load does not exceed 250V AC @ 10A or 30V DC @ 10A rating
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
