I had more than 50 pcs of MO3041 but in my circuit need operation like 817. I know i can use 817 for DC circuit but i am just want to know if i can use MO3041 in DC circuit.
I know there is a simple solution to just use a 817 Optocoupler, but i am just curious that does it possible?
No you can't.
The TRIAC based device switches on when the LED is on and the current is zero (zero crossing) and switches off when the LED is off and the current is zero. The TRIAC is on or off, nothing in between.
This device is for switching on/off devices on AC. For DC it would not work as the TRIAC would not switch off as the current needs to become zero for it to switch off (which does happen with AC).
An 817 is a linear device meaning the output current is proportional to the LED current. You can use this for voltage feedback in an isolated power supply for example. This device does not switch on/off very well.
All in all, these devices are both optical yet very different indeed.
It's perhaps possible but you would be operating in a mode that is not well characterized. The typical holding current is only 400uA so you'd have to stay well below that. Note also that the holding current typically decreases to 160uA at 100 degrees C. The zero crossing detector should not interfere for low applied voltages.
So maybe you could use it for a very slow coupler switching 20uA-50uA, implying maybe a 100K-200K pullup. If the current exceeds the holding current the device would not switch off.
All in all you're better to buy the correct thing and save those specialized devices for when you need to trigger thyristors.
