[SOLVED] Photo Coupler (Opto coupler)

[srinu9009]

Hi All

I am using Two optocouplers to my inverter mains mode to invereter mode application.I used one opto coupler for zerocrossing detector and another for mains sensing voltage.i connected these optocouplers inputs in series.is it working at all conditions?i am sending schematic as file.

if optocouplers inputs connected in parallel or in series then will it create any problems?

Like mosfets can i connect optocouplers in parallel or in series

 

[eem2am]

you dont need all those diodes to get mains crossing

you just use the one opto diode with protection diode across it and dropper res

 

[srinu9009]

Hi eem2am

Thanks for your reply.i do not undersatnd where can i place protection diode? can i use in input side of optocoupler ?

 

[FvM]

you dont need all those diodes to get mains crossing

A bridge rectifier gives 100 Hz output, your suggested protection diode circuit 50 Hz. Both serve different purposes. A symmetric 100 Hz phase angle control should use the bridge rectifier circuit, a full wave control the single diode variant.

 

[trekkytekky]

The zero crossing voltage and Mains sensing voltage outputs are also just negated versions of each other, so you could remove one of the optocouplers and replace R6 and 7 with a single 47k 2W (it would run hot at 300v) or higher wattage rating.
In your current schematic if any one of the components fail, the lot stops, so simpler with less components is less points of failure.

 

[hakeen]

Hi,

Use just one optocoupler and you will know neg-pos zero crossing. The you can calculate for pos-neg zero crossing. However keep two resistors for better performance and power dissipation (even using 4-6 resistors would be easier for power handling).

Kind regards
Hakeen