TTL Serial 4-Channel Relay Module | Self-Lock, Jog & Interlock
TTL Serial 4-Channel Relay Module | Self-Lock, Jog & Interlock
TTL Serial Port 4-Channel Relay Module Control Board
Take full control of your electronics projects with this versatile 4-Channel Relay Module Control Board. Designed for makers, engineers, and hobbyists, this compact board supports TTL serial port communication and physical key control with multiple operating modes — making it ideal for automation, robotics, smart home DIY builds, and more. Made in Mainland China.
Key Features
- 4-Channel High-Current Relay: Each relay supports up to 250V / 10A, providing strong driving capability for a wide range of loads.
- Multiple Control Modes: Supports Self-locking, Interlocking, Jog (Point Action), and Round-Trip modes — configurable via TTL serial port or onboard keys.
- Built-in Overcurrent & Reverse-Connection Protection: Safeguards your circuit and connected devices from accidental miswiring and current spikes.
- Flexible Power Input: Powered via USB Micro port or screw-type terminal blocks — 5V DC operating voltage, 100mA working current.
- Normally Open & Normally Closed Contacts: Provides maximum wiring flexibility for your application.
- LED Status Indicators: Individual LED lights for each channel offer at-a-glance relay status monitoring.
- Baud Rate & Address Configuration: Supports baud rate setting/reading and module address setting/reading via serial commands. Default baud rate: 115200 bps.
- Power-Off Memory: The reconnection status of all four relay channels supports configuration or power-off memory, so your settings persist through power cycles.
- Cascade Support: Enables single-channel and multi-channel relay cascade control for expanded automation setups.
Operating Modes Explained
- Self-Locking Mode: Press a key (or send a TTL command) to toggle a relay ON; press again to toggle it OFF. Cycles indefinitely.
- Interlocking Mode: Activating one relay automatically deactivates all others — ideal for mutually exclusive switching.
- Jog (Point Action) Mode: Relay stays ON only while the button is held; releases when the button is let go. Supported via key control only.
- Round-Trip Mode: Relay activates for a set duration (default 3 seconds), then automatically closes. Configurable up to 65,535 seconds via serial port.
Specifications
- Working Voltage: 5V DC
- Working Current: 100mA
- Communication Interface: TTL Serial
- Number of Relay Channels: 4
- Number of Onboard Keys: 4
- Relay Rating: 250V / 10A
- Default Baud Rate: 115200 bps
- Default Module Address: 0
- Default Working Mode: Self-locking
- Board Dimensions: 56 × 64 × 16 mm
Package Includes
- 1× 4-Channel Relay Module Control Board
Notes
- Due to lighting and display differences, actual color may vary slightly from product images.
- Please allow 1mm–1cm tolerance due to manual measurement.
For general electrical safety guidelines relevant to relay and low-voltage electronics projects, refer to the U.S. Consumer Product Safety Commission – Electrical Safety resource.
Frequently Asked Questions
Q: What control interfaces does this 4-channel relay module support?
A: The relay module supports two control interfaces: TTL serial port communication (allowing integration with microcontrollers such as Arduino, Raspberry Pi, and similar platforms) and onboard physical key buttons. Most operating modes (self-locking, interlocking, round-trip) are available via both interfaces; jog/point-action mode is available via key control only.
Q: How do I power the 4-channel relay control board?
A: The board can be powered in two ways: via the onboard USB Micro port for convenient 5V USB power, or through the screw-type terminal blocks for direct wired connections. The operating voltage is 5V DC with a working current of approximately 100mA.
Q: Can this relay module remember its settings after a power cycle?
A: Yes. The reconnection status of all four relay channels supports power-off memory, meaning the module can be configured to restore its previous relay states and settings (including baud rate, module address, and working mode) after power is removed and restored.
Q: What is the maximum load the relays can switch?
A: Each of the four relay channels is rated for up to 250V AC / 10A, making this board suitable for switching a wide range of loads including lamps, motors, solenoids, and other moderate-power devices. Always ensure your load does not exceed the relay's rated specifications.