4-Channel WiFi Smart Relay Module | eWeLink App Control
4-Channel WiFi Smart Relay Module | eWeLink App Control
4-Channel WiFi Smart Relay Switch Module – eWeLink, Alexa & Google Home Compatible
Take full control of your home or project automation with the Asia-Teco ST-DC4 4-Way WiFi Smart Relay Module. Whether you're automating garage doors, lights, gate motors, or any DC-powered circuit, this compact module delivers professional-grade wireless switching in three flexible modes — all managed from your smartphone or via voice commands.
Three Powerful Work Modes
- Momentary (Inching) Mode: The relay activates briefly and then automatically returns to its default state. Choose between "turn on for 1s then auto-off" or "turn off for 1s then auto-on" — ideal for door buzzers and pulse-triggered devices.
- Self-Locking Mode: The relay stays in its last triggered state until you change it — perfect for lights, fans, and appliances.
- Interlock Mode: Only one channel can be active at a time across the four relays — great for motor direction control or mutually exclusive circuits.
Switch between modes at any time with a simple tap of the physical mode button on the board.
Smart App & Voice Control
- Connects to the eWeLink app (iOS & Android) over your 2.4GHz Wi-Fi network
- Compatible with Amazon Alexa (Echo, Echo Dot, Amazon Tap) for hands-free voice control
- Works with Google Home & Google Nest
- Integrates with IFTTT — search "eWeLink Smart Home" in the IFTTT app to build custom automations
Key App Features
- Remote turn on/off from anywhere
- Timing & countdown schedules
- Device sharing with family members
- Group management for multi-relay scenes
Technical Specifications
| Model | ST-DC4 |
| Working Voltage | DC 5V – 36V |
| Rated Current | 10A per channel |
| Wi-Fi Frequency | 2.4GHz (802.11 b/g/n) |
| RF Remote Frequency | 433MHz (optional) |
| Number of Channels | 4 (Four independent relays) |
| Security Mode | Fail Secure |
| Relay Output | Dry contact (no output power — switches only) |
| Brand | Asia-Teco |
| Country of Origin | Made in Mainland China |
⚠️ Important Note: The relays are dry-contact switches with no output power. The DC 5–36V power supply input is for the PCB module only. Ensure your connected loads are wired to their own power sources.
Why Choose the Asia-Teco ST-DC4?
- ✅ One module replaces four separate smart switches
- ✅ Three configurable work modes for versatile automation
- ✅ Works on any 2.4GHz Wi-Fi — no hub required
- ✅ Voice control via Alexa or Google Home
- ✅ IFTTT support for advanced automations
- ✅ Compact form factor for easy panel or enclosure mounting
For guidance on safe electrical wiring practices and DIY home automation safety, visit the U.S. Consumer Product Safety Commission – Home Electrical Safety.
Frequently Asked Questions
Q: Does the Asia-Teco ST-DC4 WiFi relay module require a hub or bridge?
A: No hub is required. The ST-DC4 connects directly to your existing 2.4GHz Wi-Fi router and is managed entirely through the free eWeLink app on iOS or Android.
Q: What is the difference between inching, self-locking, and interlock modes on this smart relay?
A: Inching (momentary) mode triggers the relay for a brief pulse and then resets automatically — useful for gates or buzzers. Self-locking mode keeps the relay in its last state until manually changed — great for lights and fans. Interlock mode ensures only one of the four relay channels is active at any given time, which is ideal for motor direction or selector switching.
Q: Can I use this 4-channel WiFi relay module with Amazon Alexa and Google Home?
A: Yes. Once paired in the eWeLink app, you can link it to Amazon Alexa or Google Home and control each channel using voice commands such as "Alexa, turn on Channel 1" or "OK Google, turn off Channel 2."
Q: What voltage does the ST-DC4 smart switch module operate on?
A: The module's PCB runs on DC 5V to 36V. The relay contacts themselves are dry-contact (no voltage output), so your connected load will need its own power source wired through the relay terminals.