Multi-Channel AC Dimmer Control: 2CH and 4CH Guide Feb 26, 2026 0 17 TL;DR: 2CH 8A and 4CH 10A modules share one ZC pin across all channels. Each channel has its own DIM pin. One interrupt call in code covers all channels; brightness is set independently per channel ha... Arduino ESP32 ESP8266 RBDdimmer ac-dimmer multi-channel tutorial Read more
Which AC Dimmer Module to Choose: Complete Buyer's Guide Feb 26, 2026 0 26 TL;DR: Three questions determine your choice: (1) load type — resistive (heater, incandescent) or inductive (motor); (2) load power in watts → calculate amps → pick a rating with a ×1.3 safety margin;... Arduino ESP32 TRIAC ac-dimmer buyer-guide dimmerlink tutorial Read more
Zero-Cross Not Detected: AC Dimmer Doesn't Respond to Commands Feb 26, 2026 0 29 TL;DR: An AC dimmer can't regulate the load if the microcontroller isn't receiving the zero-cross signal (the sine wave crossing zero). Without this signal it's impossible to calculate the TRIAC firin... Arduino ESP32 ac-dimmer troubleshooting zero-cross Read more
Wrong Library: RBDdimmer Instead of rbdimmerESP32 on ESP32 Feb 26, 2026 0 22 TL;DR: For ESP32 you need rbdimmerESP32 — not the old RBDdimmer . The old library was written for Arduino AVR: no IRAM_ATTR , no core pinning, no race condition protection. On ESP32 it causes Guru Med... Arduino ESP32 ac-dimmer troubleshooting Read more
TRIAC Overheating: AC Dimmer Runs Hot or Burns Out Feb 26, 2026 0 23 TL;DR: A TRIAC is an active device with a voltage drop of ~1.2V. At load currents above 2A it dissipates several watts as heat. Without thermal management: overheating, thermal protection triggering, ... Arduino TRIAC ac-dimmer troubleshooting Read more
AC TRIAC Dimmer Is Not PWM: How Phase-Cut Dimming Works Feb 26, 2026 0 32 TL;DR: analogWrite() and PWM don't work with an AC TRIAC dimmer. A TRIAC is not a resistor or a DC transistor. It regulates power using phase-cut control : it opens at a precisely calculated moment ea... Arduino ESP32 TRIAC ac-dimmer troubleshooting Read more
LED Lamps with AC Dimmer: TRIAC or MOSFET — Compatibility Guide Feb 26, 2026 0 34 Short answer: There are two types of AC dimmers: TRIAC (leading edge — for incandescent bulbs, halogen, heaters) and MOSFET AC dimmer (trailing edge — purpose-built for LED lamps). If an LED lamp flic... Arduino LED MOSFET TRIAC ac-dimmer trailing-edge tutorial Read more
Trailing Edge vs Leading Edge: Which Dimmer Method to Choose Feb 26, 2026 0 39 Short answer: Leading edge is the standard TRIAC dimmer — it opens the load in the second half of each AC half-cycle (best for incandescent bulbs and heaters). Trailing edge is a MOSFET dimmer — it op... Arduino LED MOSFET TRIAC ac-dimmer leading-edge trailing-edge tutorial Read more
LED Flickering with AC Dimmer: TRIAC or MOSFET — Causes and Fixes Feb 26, 2026 0 35 Short answer: LED flickering with an AC dimmer has three distinct root causes. Types 1 and 2 are caused by TRIAC architectural incompatibility with LED lamps — the hardware fix is a MOSFET AC dimmer (... Arduino ESP32 LED MOSFET TRIAC ac-dimmer flicker tutorial Read more