Modules
4-Channel Relay Module
৳300
Four independent opto-isolated relays on one board, each with its own status LED and normally-open, normally-closed and common terminals.
Four channels in one place saves a lot of wiring when several loads need switching from one controller. Each channel is opto-isolated separately, so a fault on one switched circuit does not reach the microcontroller through the others.
What you can build
- Multi-room or multi-appliance home automation from one ESP32
- Sequenced control of pumps, valves or lights
- Test rigs that need several loads switched independently
Not sure it will work? Test your circuit free in Tekko Sim — on your phone, in Bangla or English.
| Category | Modules |
| Model no. | 4CH 5V |
| Availability | In stock |
| In stock | 3 pcs |
| Delivery | Cash on Delivery, nationwide Bangladesh |
| Channels | 4 |
| Coil Voltage | 5V DC |
| Trigger | one digital pin per channel, active LOW on most boards |
| Isolation | separate opto-coupler per channel |
| Contact Rating | up to 10A at 250V AC or 10A at 30V DC, as printed on the relay |
| Contacts | normally-open, normally-closed and common per channel |
| Coil Current | roughly 70 mA per energised channel |
Questions about the 4-Channel Relay Module
Can I power all four relays from the Arduino's 5V pin?
Not reliably. Four energised coils pull around 280 mA, which will brown out a board running on USB power. Give the module a separate 5V supply and tie the grounds together.
What is the JD-VCC jumper for?
It links the relay coil supply to the logic supply. Remove it and feed JD-VCC from its own 5V source, and the coil side stays electrically isolated from the microcontroller — worth doing whenever the switched side is mains.
Are the channels active HIGH or active LOW?
Active LOW on almost every board of this type. A channel switches on when its input pin is driven to ground.
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