Since the output is driven by a TRIAC we can drive loads upto V and the triac can conduct in both directions hence controlling AC loads will not be a problem. It also has a decent rise and fall time and hence can be used to control the output voltage. Since the output is controlled we can control the intensity of the light or the speed of a AC motor. So if you are looking for a opto-isolator to control a AC application through DC then this IC might be the right choice for you. They are normally connected to another power switch like a Triac in our case, this TRIAC will be able to provide enough current to drive the loads and will be controlled using the opto-coupler. A simple circuit diagram in which an AC bulb is controlled using a microcontroller is shown below.
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It is based on zero-crossing. MOC is mostly used to control AC load switching by automatically detecting the zero cross but it has internal TRIAC which can hold up to 1A current and IR communication keep the controlling device of optocoupler safe. The zero-crossing detector will be able to detect the zero volts from the AC and will turn on and off the TRIAC of the IC that will be able to protect the external load from damaging itself and switching surges of other circuits.
All these integrated circuits have the same pinout diagram, electrical features, and applications except IFT current that is input side LED trigger current.
The table shows the IFT current for these optoisolators. Therefore, We will consider examples for MOC only and you can apply the same concept to others also. For details of each pin consult of the table give after pinout diagram. NC Pin 3 Pin 3 is a no connection pin, which has no internal connection.
NC Pin 5 is also a no connection pin. Where to use MOC? The other part is a known monolithic silicon detector, which is used to perform the zero-cross voltage and TRIAC function. The zero-cross is mostly used in digital dimmer to generate timing signals but here it will be used only to find the zero voltage at each cycle of AC.
The AC load always turn on and off within a specific period of time. For the safety of the load, a zero-cross method is used, which detects the zero volts from the AC sign wave. By this method, the load will have a rare chance to subjected to the maximum voltages. Whenever optocoupler needs to be used some protocols need to be followed, all these protocols will be followed by the output end. The input will be delivered by output pins of the microcontrollers. The use of PWM from the controller allows the optocoupler to variate power on load.
First, draw a general operating circuit of optocoupler in proteus. In-circuit diagram as we discuss snubbing circuit with the optocoupler, in proteus, you will view some snubber less TRIAC which can be used with the circuit to make the circuit simpler.
After drawing the circuit control, it with a simple button. Then control the circuit and you will view the LAMP light up as shown in the given image. The lamp will turn on and off without any delay, which can be understood by the nature of the current. Just add an oscilloscope at the end of the load and visualize the wave nature. To understand it carefully we increase the frequency too. More Examples In MOSFETs and relay module, the optocoupler is connected to control the load but after the invention of IoT, the optocoupler is not only used as a switch it used with smart controller to perform automatic functions like: In case of an increase in room temperature the temperature sensor will detect the room temperature and will variate the speed of the cooler fan to keep the temperature normal.
This goes the same with the decrease in temperature to control the heater. In noise coupling circuit IC is used to remove the noise. Electronics valve is being controlled by using the MOC PWM input can be used as input in optocoupler to variate the output. The IC allows the external devices to receive the full load because of zero crosses.
The total power dissipation at 25 degrees is mW but it could vary with the temperature. The isolation surge voltage for optocoupler is up to VAC for 60Hz. The emitter has a reverse leakage voltage of about 6V.
PDF MOC3041 Datasheet ( Hoja de datos )
MOC3041M: Triac Driver Output Optocoupler, 6-Pin DIP 400V Zero Crossing
MOC3041 Zero Crossing Optocoupler Pinout and Examples