MOC 3041 is the Optoisolated Triac Driver that can be used to isolate AC portion of the circuit from DC operated circuit board. It helps to prevents the damage of DC circuit when there is an accidental leakage of AC in Triac controlled lamp driver circuits.
MOC 3041 has built in Zero Crossing Sensing ( ZCS) for On / Off applications. The chip has an LED and an optically active SCR in a common package. The LED is driven by the DC output voltage from the circuit while the Optically active SCR carries 230 volt AC. The SCR drops the 230 V AC to low volt AC and rectifies it into DC for driving the gate of external Triac. When the output from the DC circuit comes, the LED inside the MOC turns on. This triggers the SCR and MOC gives DC output to drive the Triac.
MOC 3041 has 6 pins and pin 1 is the Anode of LED and pin 2 is its Cathode. Pin 6 receives 230V AC while pin 4 gives output voltage to drive the Triac.
The circuit given below is a Lamp Dimmer with MOC isolation. The DC circuit board has a variable output either controlled by a Variable resistor or Microcontroller. Depending on the output voltage from the DC board, the LED inside the MOC varies in brightness. As a result, the voltage from the SCR varies to provide a varying voltage to the gate of external Triac. The lamp connected between the M2 pin of Triac and the Neutral line shows the varying brightness accordingly. If a steady output voltage is given to MOC, it acts like an On/ Off switch for the lamp.
Caution : The circuit carries high voltage and gives Fatal Shock if handled carelessly. Do not attempt to build this circuit unless you are competent to handle high volt circuits. Do not touch the MOC and the circuit when connected to Mains.