Digital AC Voltage Dimmer

Opto-isolated AC Voltage dimmer with ATtiny13A (1KB flash) and two push buttons.

Link of the actual product: LINK

This opto-isolated module can control AC voltage by detecting the phase of AC line. No need for an arduino. It has a tiny 8pin microcontroller (ATtiny13A) under its PCB which does all the work. It detects when the AC voltage is crossing zero voltage line and for a short period of time it turns on triac and again within that same half cycle turns it off. It has five input pins: 5V, GND, Relay, + and -. A 100mS low pulse to +/- pin will increase/decrease the AC load voltage by 1/20th of 220V. Beside +/- pins it has two push buttons (++ and --) which does the same thing. A status LED will indicate voltage max and min levels. The module consists of push buttons, BTA16A triac for turning on and off loads, two optocouplers (one for zero cross detection & another for isolation), 4 diodes for rectification of AC and one RC snubber IC for inductive loads.