8CHANNEL-5V/12V RELAY MODULE

Description

🔌 8-Channel 5V/12V Relay Module – Professional Multi-Relay Board with Optocoupler Isolation

The 8-Channel 5V/12V Relay Module is a professional-grade relay control board featuring eight independent relay channels with built-in driver circuits, optocoupler isolation, LED indicators, and screw terminals. This comprehensive module allows simultaneous control of up to eight separate loads, making it perfect for complex automation, smart home systems, industrial control, and multi-zone applications. With dual voltage support (5V or 12V) and complete electrical isolation per channel, this module provides safe, reliable switching for demanding projects requiring multiple outputs.

✨ Key Highlights

⚡ 8 Independent Relay Channels – Control up to 8 separate loads simultaneously
🔋 Dual Voltage Support – Works with 5V or 12V input (jumper selectable)
🔒 Full Optocoupler Isolation – PC817 isolation on every channel
🔌 10A Per Channel – Each relay rated 250VAC/30VDC @ 10A
💡 9x LED Indicators – Power LED + status LED for each of 8 relays
🔧 Professional Screw Terminals – Easy, secure wire connections for all contacts
📱 3.3V Logic Compatible – Works with ESP8266, ESP32, Raspberry Pi
🛡️ Complete Driver Circuits – No external components needed
🔄 Flexible Configuration – Active High/Low selectable per channel
🏭 Industrial-Grade PCB – Professional board with mounting holes

📊 Technical Specifications

Specification	Details
🔌 Module Type	8-Channel Relay Module Board
🔢 Number of Relays	8 independent channels
⚡ Operating Voltage	5V DC or 12V DC (jumper selectable per channel)
🔋 Voltage Range	4.5-5.5V (5V mode) / 10.8-14.4V (12V mode)
💡 Control Signal Input	3.3V – 5V compatible (optocoupler isolated)
📡 Trigger Current	~2-5mA per channel (low current, MCU-friendly)
🔋 Module Current Draw	~320mA @ 5V (all relays ON) / ~180mA @ 12V (all relays ON)
🔧 Trigger Logic	Active High or Active Low (jumper selectable per channel)
🔒 Isolation	PC817 optocoupler per channel (8x total)
🔌 Relay Type	SRD-05VDC-SL-C or SRD-12VDC-SL-C (SPDT) x8
⚡ Contact Rating (AC)	10A @ 250VAC / 10A @ 125VAC per channel
🔋 Contact Rating (DC)	10A @ 30VDC / 10A @ 28VDC per channel
💪 Maximum Switching Power	2500VA (AC) / 300W (DC) per channel
🔌 Contact Configuration	SPDT (Form C) x8 – Each has NO, NC, COM terminals
💡 LED Indicators	1x Power LED (red), 8x Relay Status LEDs (green/blue)
🔧 Terminals	Screw terminals for power and all 24 relay contacts (8×3)
📌 Control Interface	10-pin header (VCC, GND, IN1-IN8)
⏱️ Response Time	≤10ms (pickup), ≤5ms (release) per relay
🔄 Relay Lifespan	100,000 operations (rated load) per relay
🌡️ Operating Temperature	-10°C to +60°C
💧 Humidity	20% to 80% RH (non-condensing)
📏 PCB Dimensions	~138mm x 52mm x 19mm (L x W x H)
⚖️ Weight	~95g
🔩 Mounting Holes	4x M3 mounting holes (3mm diameter)

🔌 Terminal & Pin Configuration

Terminal/Pin	Function	Connection
VCC (DC+)	Power Input	Connect to +5V or +12V power supply
GND (DC-)	Ground	Connect to power supply ground
IN1 to IN8	Relay Control Inputs	Connect to MCU GPIO pins (3.3V or 5V)
CH1-CH8 COM	Common Contacts	Connect to load or power source (8x)
CH1-CH8 NO	N.O. Contacts	Closed when corresponding relay energized (8x)
CH1-CH8 NC	N.C. Contacts	Open when corresponding relay energized (8x)

🔄 Channel Assignment

Control Pin	Relay Channel	Status LED	Screw Terminals
IN1	Relay 1	LED1	CH1: COM, NO, NC
IN2	Relay 2	LED2	CH2: COM, NO, NC
IN3	Relay 3	LED3	CH3: COM, NO, NC
IN4	Relay 4	LED4	CH4: COM, NO, NC
IN5	Relay 5	LED5	CH5: COM, NO, NC
IN6	Relay 6	LED6	CH6: COM, NO, NC
IN7	Relay 7	LED7	CH7: COM, NO, NC
IN8	Relay 8	LED8	CH8: COM, NO, NC

💡 LED Indicator Status

LED	Color	Status Indication
Power LED	Red	ON = Module powered correctly
Relay 1-8 LEDs	Green/Blue	ON = Corresponding relay energized (contact switched)

🎯 Perfect For

Application	Description
🏠 Whole Home Automation	8-room lighting, multi-zone control, complete house automation
🏢 Building Management	Office lighting zones, HVAC control, access control systems
🌱 Advanced Garden Automation	8-zone irrigation, multiple pumps, lighting, ventilation, heaters
🏭 Industrial Control Panels	Multi-equipment control, process automation, conveyor systems
🎭 Stage/Event Control	Multi-zone lighting, effects control, equipment sequencing
💡 Smart Lighting Systems	8-zone lighting, scene control, architectural lighting
🏊 Pool/Spa Automation	Pump, heater, lights, jets, sanitizer, waterfall control
🔐 Multi-Door Access Control	8 doors, gates, locks, turnstiles, barriers
🚨 Security Systems	Multi-zone alarms, sirens, strobes, notification systems
📡 IoT Central Control Hub	WiFi-controlled multi-device automation, smart building
🌡️ Complex HVAC Systems	Multi-zone heating, cooling, fans, dampers, humidifiers
🤖 Advanced Robotics	Multi-motor control, actuators, pneumatics, complex automation

📦 Package Contents

✅ 1x 8-Channel Relay Module Board (5V/12V compatible)
✅ 8x Pre-installed relays with optocouplers
✅ Complete screw terminals for power and all 24 relay contacts
✅ 10-pin control header (may require male-to-female jumper wires)
✅ 9x LED indicators pre-installed (power + 8x relay status)
⚠️ Note: Jumper wires NOT included (Dupont wires recommended)
⚠️ Note: 5V/12V power supply NOT included (min 2A for 5V, 1A for 12V)
⚠️ Note: Mounting screws NOT included

💻 Arduino Code Examples

Basic 8-Channel Sequential Control

Code Snippet

Code Snippet
`// Define relay control pins const int RELAY_PINS[8] = {2, 3, 4, 5, 6, 7, 8, 9}; void setup() { // Initialize all relay pins for (int i = 0; i < 8; i++) { pinMode(RELAY_PINS[i], OUTPUT); digitalWrite(RELAY_PINS[i], LOW); // All OFF } Serial.begin(9600); Serial.println("8-Channel Relay Module Ready"); }` void loop() { // Turn ON relays sequentially for (int i = 0; i < 8; i++) { Serial.print("Relay "); Serial.print(i + 1); Serial.println(" ON"); digitalWrite(RELAY_PINS[i], HIGH); delay(500); // 500ms between each } delay(2000); // All ON for 2 seconds // Turn OFF relays sequentially for (int i = 0; i < 8; i++) { Serial.print("Relay "); Serial.print(i + 1); Serial.println(" OFF"); digitalWrite(RELAY_PINS[i], LOW); delay(500); } delay(2000); // All OFF for 2 seconds }



// Define relay control pins

const int RELAY_PINS[8] = {2, 3, 4, 5, 6, 7, 8, 9};
void setup() {

  // Initialize all relay pins

  for (int i = 0; i < 8; i++) {

    pinMode(RELAY_PINS[i], OUTPUT);

    digitalWrite(RELAY_PINS[i], LOW); // All OFF

  }

  Serial.begin(9600);

  Serial.println("8-Channel Relay Module Ready");

}

void loop() { // Turn ON relays sequentially for (int i = 0; i < 8; i++) { Serial.print("Relay "); Serial.print(i + 1); Serial.println(" ON"); digitalWrite(RELAY_PINS[i], HIGH); delay(500); // 500ms between each } delay(2000); // All ON for 2 seconds // Turn OFF relays sequentially for (int i = 0; i < 8; i++) { Serial.print("Relay "); Serial.print(i + 1); Serial.println(" OFF"); digitalWrite(RELAY_PINS[i], LOW); delay(500); } delay(2000); // All OFF for 2 seconds }

Multi-Zone Lighting Control

Code Snippet

Code Snippet
const int ZONES[8] = {2, 3, 4, 5, 6, 7, 8, 9}; const char* ZONE_NAMES[8] = { "Living Room", "Kitchen", "Bedroom 1", "Bedroom 2", "Bathroom", "Hallway", "Garage", "Outdoor" }; void setup() { for (int i = 0; i < 8; i++) { pinMode(ZONES[i], OUTPUT); digitalWrite(ZONES[i], LOW); } Serial.begin(9600); } void allLightsOn() { for (int i = 0; i < 8; i++) { digitalWrite(ZONES[i], HIGH); } Serial.println("All zones ON"); } void allLightsOff() { for (int i = 0; i < 8; i++) { digitalWrite(ZONES[i], LOW); } Serial.println("All zones OFF"); } void setZone(int zone, bool state) { if (zone >= 0 && zone < 8) { digitalWrite(ZONES[zone], state); Serial.print(ZONE_NAMES[zone]); Serial.println(state ? " ON" : " OFF"); } } `void loop() { // Example: Evening scene setZone(0, HIGH); // Living room ON setZone(1, HIGH); // Kitchen ON setZone(7, HIGH); // Outdoor ON delay(10000); // Night mode: Turn all OFF allLightsOff(); delay(5000); }`



const int ZONES[8] = {2, 3, 4, 5, 6, 7, 8, 9};

const char* ZONE_NAMES[8] = {

  "Living Room", "Kitchen", "Bedroom 1", "Bedroom 2",

  "Bathroom", "Hallway", "Garage", "Outdoor"

};
void setup() {

  for (int i = 0; i < 8; i++) {

    pinMode(ZONES[i], OUTPUT);

    digitalWrite(ZONES[i], LOW);

  }

  Serial.begin(9600);

}
void allLightsOn() {

  for (int i = 0; i < 8; i++) {

    digitalWrite(ZONES[i], HIGH);

  }

  Serial.println("All zones ON");

}
void allLightsOff() {

  for (int i = 0; i < 8; i++) {

    digitalWrite(ZONES[i], LOW);

  }

  Serial.println("All zones OFF");

}
void setZone(int zone, bool state) {

  if (zone >= 0 && zone < 8) {

    digitalWrite(ZONES[zone], state);

    Serial.print(ZONE_NAMES[zone]);

    Serial.println(state ? " ON" : " OFF");

  }

}

void loop() { // Example: Evening scene setZone(0, HIGH); // Living room ON setZone(1, HIGH); // Kitchen ON setZone(7, HIGH); // Outdoor ON delay(10000); // Night mode: Turn all OFF allLightsOff(); delay(5000); }

ESP32 WiFi 8-Channel Web Control

Code Snippet

Code Snippet
#include <WiFi.h> #include <WebServer.h> const int RELAYS[8] = {16, 17, 18, 19, 21, 22, 23, 25}; const char* ssid = "YourWiFi"; const char* password = "YourPassword"; WebServer server(80); bool relayStates[8] = {0}; void setup() { for (int i = 0; i < 8; i++) { pinMode(RELAYS[i], OUTPUT); digitalWrite(RELAYS[i], LOW); } WiFi.begin(ssid, password); while (WiFi.status() != WL_CONNECTED) delay(500); // Setup web endpoints for each relay for (int i = 0; i < 8; i++) { String onPath = "/relay" + String(i+1) + "/on"; String offPath = "/relay" + String(i+1) + "/off"; server.on(onPath.c_str(), [i]() { digitalWrite(RELAYS[i], HIGH); relayStates[i] = true; server.send(200, "text/plain", "Relay " + String(i+1) + " ON"); }); server.on(offPath.c_str(), [i]() { digitalWrite(RELAYS[i], LOW); relayStates[i] = false; server.send(200, "text/plain", "Relay " + String(i+1) + " OFF"); }); } // All ON/OFF endpoints server.on("/all/on", []() { for (int i = 0; i < 8; i++) { digitalWrite(RELAYS[i], HIGH); relayStates[i] = true; } server.send(200, "text/plain", "All relays ON"); }); server.on("/all/off", []() { for (int i = 0; i < 8; i++) { digitalWrite(RELAYS[i], LOW); relayStates[i] = false; } server.send(200, "text/plain", "All relays OFF"); }); server.begin(); } `void loop() { server.handleClient(); } // Access: http://[ESP32_IP]/relay1/on, /relay2/off, /all/on, etc.`



#include <WiFi.h>

#include <WebServer.h>
const int RELAYS[8] = {16, 17, 18, 19, 21, 22, 23, 25};

const char* ssid = "YourWiFi";

const char* password = "YourPassword";
WebServer server(80);

bool relayStates[8] = {0};
void setup() {

  for (int i = 0; i < 8; i++) {

    pinMode(RELAYS[i], OUTPUT);

    digitalWrite(RELAYS[i], LOW);

  }

  

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) delay(500);

  

  // Setup web endpoints for each relay

  for (int i = 0; i < 8; i++) {

    String onPath = "/relay" + String(i+1) + "/on";

    String offPath = "/relay" + String(i+1) + "/off";

    

    server.on(onPath.c_str(), [i]() {

      digitalWrite(RELAYS[i], HIGH);

      relayStates[i] = true;

      server.send(200, "text/plain", "Relay " + String(i+1) + " ON");

    });

    

    server.on(offPath.c_str(), [i]() {

      digitalWrite(RELAYS[i], LOW);

      relayStates[i] = false;

      server.send(200, "text/plain", "Relay " + String(i+1) + " OFF");

    });

  }

  

  // All ON/OFF endpoints

  server.on("/all/on", []() {

    for (int i = 0; i < 8; i++) {

      digitalWrite(RELAYS[i], HIGH);

      relayStates[i] = true;

    }

    server.send(200, "text/plain", "All relays ON");

  });

  

  server.on("/all/off", []() {

    for (int i = 0; i < 8; i++) {

      digitalWrite(RELAYS[i], LOW);

      relayStates[i] = false;

    }

    server.send(200, "text/plain", "All relays OFF");

  });

  

  server.begin();

}

void loop() { server.handleClient(); } // Access: http://[ESP32_IP]/relay1/on, /relay2/off, /all/on, etc.

✅ Advantages of 8-Channel Module

Feature	Benefit
🔢 8 Independent Channels	Control 8 separate loads – complete automation solution
📐 Highly Space Efficient	Much smaller than 8 individual relay modules
💰 Cost Effective	Significantly cheaper than buying 8 separate modules
🔌 Simplified Wiring	Single power connection for all 8 relays
🔒 8x Optocoupler Isolation	Each channel independently isolated for maximum safety
💡 Individual LED Status	Visual feedback for all 8 channels at a glance
⚡ Full 10A Per Channel	All 8 relays can handle 10A simultaneously (total 80A capacity)
🔧 Per-Channel Configuration	Mix Active High/Low as needed for each relay
🏭 Professional Build Quality	Industrial-grade PCB with proper isolation and protection
🌐 Complete Automation Hub	Central control point for whole-home or building automation

⚠️ Important Safety & Usage Notes

⚡ Adequate power supply required – Min 2A @ 5V or 1A @ 12V for all relays
🔌 Common ground essential – Module GND and MCU GND must connect
⚠️ AC VOLTAGE IS DANGEROUS – 250VAC can be lethal; hire qualified electrician
🔒 Verify all jumper settings – Check Active High/Low for each channel before testing
💪 10A maximum per channel – Do not exceed per-relay rating
🔥 Heat dissipation critical – With 8 relays under load, adequate cooling essential
🛡️ Independent but shared power – All channels draw from same power supply
📏 Organize AC wiring carefully – Keep high voltage traces separated and labeled
🌡️ Monitor operating temperature – Module generates significant heat with multiple loads
🔧 Double-check all 24 terminals – Verify tight connections on all screw terminals
⚡ Individual circuit protection – Use separate fuse for each load circuit
📱 GPIO pin planning – Reserve 8 consecutive or well-organized GPIO pins
🔋 Inrush current consideration – Switching 8 loads simultaneously may cause voltage dip
🏭 Professional enclosure required – Use properly rated electrical enclosure for safety

🔍 Troubleshooting Guide

Problem	Possible Cause	Solution
Only Some Relays Work	Insufficient power supply current	✅ Use higher capacity PSU (min 2A @ 5V, 1A @ 12V)
Relays Won’t All Switch Together	Voltage drop when all activate	✅ Add 1000µF capacitor across VCC/GND, use regulated PSU
Specific Channel Not Working	Bad optocoupler or relay on that channel	✅ Test IN signal with multimeter, check jumper, replace module if needed
Power LED On, No Relays Work	Control signals not connected or wrong voltage	✅ Verify IN1-IN8 connections, check common ground
Module Resets Randomly	Power supply overload or voltage sag	✅ Use larger PSU, add bulk capacitor (2200µF), check wire gauge
Inconsistent Operation	Poor power supply regulation	✅ Use quality switching PSU, avoid cheap adapters
Module Gets Very Hot	Multiple high-current loads or inadequate ventilation	✅ Add cooling fan, reduce load currents, improve airflow
ESP32 Crashes When Switching	Shared power causing voltage fluctuation	✅ Use separate regulated 3.3V for ESP32, common ground only

🔌 Power Supply Sizing Guide

Voltage	Minimum Current	Recommended Current	Notes
5V	1.5A	2A or higher	~320mA for all 8 relays + margin
12V	500mA	1A or higher	~180mA for all 8 relays + margin
Note: Add MCU current draw (ESP32 ~500mA, Arduino ~50mA) if powering from same supply

💡 Pro Tips for 8-Channel Projects

🔧 Use terminal block labeling – Number each relay 1-8 clearly on enclosure
📏 Color-code all wiring – Different colors for each relay circuit
⚡ Staged power-up – Turn on relays sequentially to reduce inrush
🛡️ DIN rail mounting – Professional installation in electrical panel
💾 State preservation – Save relay states to EEPROM for power loss recovery
📋 Comprehensive wiring diagram – Document all 24 contact connections
🔒 Interlock logic – Prevent conflicting relay combinations in code
⏰ Watchdog timer – Auto-reset if system hangs
🌐 Status reporting – Implement MQTT state messages for all 8 channels
📱 Mobile dashboard – Create 8-button interface showing all states
🔋 Dedicated PSU per module – Don’t share PSU with other high-current devices
🔧 Emergency shutoff – Physical button to turn all relays OFF
🌡️ Temperature monitoring – Add thermistor to detect overheating
📊 Usage logging – Track which relays are used most for maintenance planning

🆚 Multi-Channel Relay Module Comparison

Feature	1-Channel	2-Channel	4-Channel	8-Channel
Number of Loads	1 device	2 devices	4 devices	8 devices
GPIO Pins Used	1 pin	2 pins	4 pins	8 pins
Board Size	~50x38mm	~51x39mm	~75x52mm	~138x52mm
Power @ 5V	~40mA	~80mA	~160mA	~320mA
Best For	Simple switching	Dual control	Multi-room	Complete automation
Complexity	⭐ Simple	⭐⭐ Moderate	⭐⭐⭐ Advanced	⭐⭐⭐⭐ Professional
Relative Cost	💰 Base	💰💰 1.5x	💰💰💰 2.5x	💰💰💰💰 4x

🏠 Example 8-Zone Smart Home Setup

Channel	Zone/Device	Load Type	Typical Use
CH1	Living Room Lights	LED (100W)	Evening automation, scenes
CH2	Kitchen Lights	LED (80W)	Motion sensor control
CH3	Bedroom 1 Lights	LED (60W)	Schedule, voice control
CH4	Bedroom 2 Lights	LED (60W)	Schedule, voice control
CH5	Bathroom Exhaust Fan	Motor (50W)	Auto-timer, humidity sensor
CH6	Outdoor Lights	LED (150W)	Dusk-to-dawn, security
CH7	Garage Door Opener	Motor (500W)	Remote access, status
CH8	Garden Irrigation	Solenoid (15W)	Scheduled watering zones

🛡️ Warranty & Support

✅ Complete 8-channel relay module with all driver circuits
✅ 8x optocoupler isolation for maximum safety (PC817)
✅ High-quality 10A relays per channel (SRD series)
✅ Individual LED indicators for each relay + power LED
✅ Professional screw terminals for all 26 connections
✅ Compatible with Arduino, Raspberry Pi, ESP32, ESP8266
✅ Dual voltage support (5V/12V selectable)
✅ Independent trigger mode configuration per channel
✅ Pre-tested all 8 channels before shipping
✅ Comprehensive technical documentation and example code
✅ Industrial-grade PCB with mounting holes
✅ Fast replacement for defective units
⚠️ Important: High voltage AC wiring MUST be performed by qualified electrician. Always disconnect all power before wiring. Use properly rated electrical enclosure. Ensure adequate power supply (min 2A @ 5V or 1A @ 12V). Each relay can handle 10A independently, but consider total heat dissipation with multiple high-current loads. Provide adequate ventilation and cooling.

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8CHANNEL-5V/12V RELAY MODULE

Shipping Policy

Safe Checkout

Description

🔌 8-Channel 5V/12V Relay Module – Professional Multi-Relay Board with Optocoupler Isolation

✨ Key Highlights

📊 Technical Specifications

🔌 Terminal & Pin Configuration

🔄 Channel Assignment

💡 LED Indicator Status

🎯 Perfect For

📦 Package Contents

💻 Arduino Code Examples

Basic 8-Channel Sequential Control

Multi-Zone Lighting Control

ESP32 WiFi 8-Channel Web Control

✅ Advantages of 8-Channel Module

⚠️ Important Safety & Usage Notes

🔍 Troubleshooting Guide

🔌 Power Supply Sizing Guide

💡 Pro Tips for 8-Channel Projects

🆚 Multi-Channel Relay Module Comparison

🏠 Example 8-Zone Smart Home Setup

🛡️ Warranty & Support

Customer Reviews

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8CHANNEL-5V/12V RELAY MODULE

Shipping Policy

Safe Checkout

Description

🔌 8-Channel 5V/12V Relay Module – Professional Multi-Relay Board with Optocoupler Isolation

✨ Key Highlights

📊 Technical Specifications

🔌 Terminal & Pin Configuration

🔄 Channel Assignment

💡 LED Indicator Status

🎯 Perfect For

📦 Package Contents

💻 Arduino Code Examples

Basic 8-Channel Sequential Control

Multi-Zone Lighting Control

ESP32 WiFi 8-Channel Web Control

✅ Advantages of 8-Channel Module

⚠️ Important Safety & Usage Notes

🔍 Troubleshooting Guide

🔌 Power Supply Sizing Guide

💡 Pro Tips for 8-Channel Projects

🆚 Multi-Channel Relay Module Comparison

🏠 Example 8-Zone Smart Home Setup

🛡️ Warranty & Support

Customer Reviews

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