AC Dimmer Module 4A for Arduino ESP32 – Compact TRIAC Dimmer 400V 4A, 3.3V/5V Logic, Phase Control for Lights Fans Small Appliances – DIY Smart Home Automation Module

Price: $8.99
(as of Jul 03, 2026 18:31:42 UTC – Details)
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Compact AC Dimmer Module for Light-Duty Automation Projects
The RBDimmer.com 4A Module is a compact, affordable AC dimmer designed for makers and hobbyists who need smooth voltage control for low-power AC loads. This DIY module connects to your microcontroller to enable precise dimming of incandescent lights, small fans, pumps, and other appliances up to 4A.
Small Size, Big Possibilities
Measuring just 60 × 20 × 20 mm, this is one of the most compact AC dimmers available. The tiny footprint makes it perfect for projects where space is limited: custom smart wall switches, lamp controllers, small appliance automation, or any application requiring a discreet installation.
Smooth, Flicker-Free Control
The BTA136 TRIAC delivers true phase-angle dimming for smooth brightness transitions. Unlike relay-based solutions that only switch on and off, this module provides continuous voltage regulation across the entire range. Create gradual wake-up lighting, comfortable ambiance control, or variable-speed fan operation.
Ideal Applications:
– Smart lighting – Dim incandescent and halogen lamps smoothly
– Fan speed control – Adjust small ventilation fans for quiet operation
– Pump regulation – Control small water pumps and fountains
– Air purifiers – Variable speed for noise reduction
– Heating elements – Low-power soldering stations, small heaters
– DIY projects – Custom smart switches and automation devices
Universal Microcontroller Support
With support for 3.3V, 5V, and even 12V logic levels, the module works with virtually any microcontroller platform. The rbdimmerESP32 library handles interrupt timing and TRIAC control, letting you focus on your application logic rather than low-level coding.
Smart Home Ready
Integrate seamlessly with popular platforms: use ESPHome for Home Assistant dashboards, flash Tasmota for cloud control and scheduling, or build completely custom solutions. Voice control through Alexa or Google Home is just a configuration away.
Safe and Reliable
Optocoupler isolation completely separates the dangerous AC mains from your sensitive electronics. The zero-cross detection output ensures your microcontroller can synchronize precisely with the AC waveform for optimal dimming performance.
What’s Included: AC Dimmer Module 4A, access to online documentation, wiring diagrams, and example code.

COMPACT LOW-POWER AC DIMMING – Control AC loads up to 4A at 400V with smooth phase-angle regulation. Perfect for dimmable incandescent lights, small fans, pumps, air purifiers, and low-power heating elements. True voltage control, not just on/off switching.
ULTRA-COMPACT DESIGN – Tiny footprint (60 × 20 × 20 mm) fits easily into small enclosures and tight spaces. Ideal for DIY smart switches, lamp controllers, and space-constrained automation projects where larger modules won’t fit.
ARDUINO & ESP32 COMPATIBLE – Supports 3.3V, 5V, and 12V logic levels for universal microcontroller compatibility. Works with Arduino, ESP32, ESP8266, STM32, Raspberry Pi, and more. Ready-to-use rbdimmerESP32 library simplifies coding with example projects.
SMART HOME INTEGRATION – Direct compatibility with ESPHome for Home Assistant, Tasmota firmware, and custom automation platforms. Build voice-controlled lighting, scheduled operations, and energy-saving routines through your preferred smart home ecosystem.
SAFE OPTOCOUPLER ISOLATION – Complete electrical separation between high-voltage AC and low-voltage control circuit protects your microcontroller. Zero-cross detection output enables precise timing synchronization for flicker-free dimming.