AC Dimmer Module 8A, 1 channel, 3.3V/5V logic, AC 400V-8A
Overview
The AC Dimmer Module is a TRIAC-based board for smooth AC power regulation — not just on/off switching. It adjusts the voltage delivered to your load by controlling the TRIAC firing angle on every AC half-cycle, enabling true brightness dimming, precise heater temperature control, and variable motor or fan speed.
This 8A single-channel module is designed for DIY and prototyping. Connect it to any microcontroller, send a value from 0 to 100%, and the module handles all the AC timing. It supports 3.3V and 5V logic levels, so it works directly with Arduino, ESP32, Raspberry Pi, STM32, and most development boards without additional level shifters.
Use Cases
- Lighting control: Smoothly dim incandescent or halogen bulbs — set the right ambiance, simulate sunrise/sunset for wake-up automations, or fade lights in/out on events.
- Heater regulation: Implement a closed-loop thermostat — read temperature from a sensor and adjust heater power to hold a setpoint, instead of noisy on/off cycling.
- Fan speed control: Run ventilation, exhaust, or cooling fans at exactly the speed needed, reducing noise and energy consumption.
- Pump flow control: Adjust water or air pump output for aquariums, irrigation systems, or pneumatic applications.
- Smart home integration: Control from Home Assistant via the ESPHome component or Tasmota — use dashboards, automations, or voice assistants.
- Energy optimization: Schedule operation, ramp down power during off-peak hours; the rbdimmerESP32 library handles 50/60 Hz auto-detection automatically.
Technical Specifications
| Parameter | Value |
|---|---|
| Maximum Voltage | 400V AC |
| Maximum Current | 8A |
| AC Frequency | 50 / 60 Hz (auto-detected by library) |
| TRIAC | BTA16-600B |
| Isolation | Optocoupler |
| Logic Levels | 3.3V / 5V / 12V |
| Zero-Cross Detection | External signal required (from MCU or sensor) |
| Minimum Signal Current | 10 mA |
| Weight | 19 g |
| Dimensions | 80 × 40 × 40 mm |
Platform Compatibility
The module needs two signals from your microcontroller: a zero-cross detection pulse (provided by the Voltage Zero-Cross Sensor) and a PWM-style control value. It works with any platform that has 3.3V/5V digital output:
- Arduino (Uno, Mega, Nano) — full support via the RBDDimmer — Alrduino boards library (backward-compatible with AVR)
- ESP32 — rbdimmerESP32 library library, ESPHome external component, Tasmota
- ESP8266 — basic support; prefer ESP32 for multi-channel setups
- Raspberry Pi — Recomind to use DimmerLink module.
- STM32, PIC, and other MCUs — any platform with 3.3V/5V digital output
rbdimmerESP32 Library
The rbdimmerESP32 library manages hardware interrupts and high-precision timers so your application code stays clean and focused on logic. Key features:
- Compatible with Arduino IDE, ESP-IDF, and ESPHome frameworks
- Multi-channel control on independent GPIO pins
- Configurable dimming curves: linear, RMS, logarithmic
- Smooth transitions with configurable ramp speed
- Automatic 50/60 Hz grid frequency detection
- Callback functions for synchronisation with other system events
Documentation
- Dimmer Selection Guide — how to choose the right module
- Wiring. Hardware connection diagram
- rbdimmerESP32 Library — Arduino & ESP-IDF guide
- ESPHome external component