The HCW-M421 DC 6V~30V Multifunction Trigger Delay Time Module is a versatile and powerful timing control relay designed for Arduino, DIY electronics, and industrial automation projects. With support for multiple operating modes, this module can be used as a time delay relay, cycle timer, or trigger control switch for a wide range of AC and DC applications.

It features a wide voltage input (6V–30V DC), precise timing adjustment from 0.1 seconds to 999 minutes, and a digital display for easy configuration. Thanks to its dual-MOS parallel drive design, the relay supports loads up to 30V DC / 15A or 220V AC / 5A, making it suitable for controlling motors, LED lights, pumps, solenoid valves, and other devices.

This module is highly popular in Bangladesh for smart home automation, motor control, and protective relay applications.

Features:

• Wide Input Voltage: 6V – 30V DC (compatible with 5V, 12V, and 24V systems)

• Timing Range: 0.1 seconds to 999 minutes (continuously adjustable)

• Multiple Modes: P1.1, P1.2, P1.3, P2, P3.1, P3.2, and P4 for flexible use cases

• Digital Display: Clear LED interface for settings and status

• Cycle Timer Function: Supports repeated ON/OFF operation with adjustable parameters

• Emergency Stop Function: Quick shutdown with STOP key

• Reverse Polarity Protection: Prevents damage if power supply is connected incorrectly

• Sleep Mode: Saves power when idle

• Long Life & High Reliability: MOSFET drive ensures no sparks, noise, or EMI

• Industrial Grade PCB: Built-in optocoupler for enhanced anti-jamming performance

Specifications:

• Operating Voltage: 6V – 30V DC

• Trigger Source: 3.0V–24V active-high signal (with optocoupler isolation)

• Output Capacity:

  • DC: 5V–36V @ 15A (max 30A with proper cooling)

  • AC: 220V AC @ 5A

• Quiescent Current: 20mA

• Operating Current: 50mA

• Load Power: Up to 400W

• Relay Life: 10 million+ cycles

• Working Temperature: -40°C to +85°C

• Module Size: 6.0 × 3.4 × 1.2 cm

• Display Modes: Seconds, tenths of seconds, minutes (via decimal selection)

Applications:

• Smart home automation systems

• LED light control and timed switching

• Motor and pump control

• Aquarium and greenhouse automation

• DIY Arduino and Raspberry Pi projects

• Industrial automation timing control

• Over-voltage or delayed power protection

How to Use:

The HCW-M421 timer relay module is a multifunction delay switch that allows you to control devices such as LED lights, motors, pumps, solenoid valves, fans, and DIY automation projects. It supports multiple operating modes and adjustable timing from 0.1 seconds up to 999 minutes.

Step 1: Power Connection

• Connect VCC (+) to DC 6V–30V power supply positive.

• Connect GND (-) to power supply negative.

• The display will power on and show the current mode (default P1.1).

⚠️ Note: The module output is active output. The output voltage is the same as the input voltage. Do not short DC- with Load-, otherwise the load will always stay powered.

Step 2: Load Connection

The relay output uses a MOSFET switching circuit. Connect your load as follows:

• DC+ → Load positive terminal

• Load- → Load negative terminal

Supports:

• DC load up to 30V, 5A continuous (15A peak with cooling)

• AC load up to 220V, 5A (with relay version)

Step 3: Selecting Time Range

You can set delay times between 0.1s and 999 minutes.

• Short press STOP to select the decimal point position:

  • X.X → 0.1 to 99.9 seconds

  • XXX. → 1 to 999 seconds

  • X.X.X → 1 to 999 minutes

Example: To set 3.2 seconds, move the decimal to tens place → display shows 03.2.

Step 4: Operating Modes

The module has multiple timing modes (P1.1 – P4).

• P1.1 → On for “OP” time, then Off. (Trigger ignored during delay)

• P1.2 → On for “OP” time, then Off. (Trigger resets timer)

• P1.3 → On for “OP” time, then Off. (Trigger stops timer)

• P2 → Off for “CL” time, On for “OP” time, then Off.

• P3.1 → Cyclic: On “OP”, Off “CL”, repeat for “LOP” times (trigger controlled).

• P3.2 → Cyclic: On “OP”, Off “CL”, repeat continuously (auto run).

• P4 → Signal holding: relay stays On while signal is present, then waits “OP” before turning Off.

Step 5: Setting Parameters (OP, CL, LOP)

1. Long press SET (2 sec) → enter mode selection.

2. Use UP/DOWN to choose mode (P1.1–P4).

3. Short press SET → select parameter to adjust:

   • OP = On-time

   • CL = Off-time

   • LOP = Loop count (1–999, or --- for infinite)

4. Adjust values with UP/DOWN.

5. Press STOP → choose decimal (time range).

6. Long press SET (2 sec) to save and return to main screen.

Step 6: STOP Button Functions

• Emergency Stop: Short press STOP → relay turns OFF immediately.

• Relay Enable/Disable: Toggle between ON (enabled) and OFF (disabled).

• Sleep Mode: Long press STOP (2 sec) → switch between:

  • C-P → Sleep mode (display off after 5 min, relay works normally)

  • O-d → Display always on