Switch on zero current crossing

[Stephane38]

Hi,

I use a perfect current source and I know the frequency. So I use a SW to close my switch each time the current cross zero and I can also controlling the Ton.
But now I want to use a random current source and I can't predict when the current will cross zero.

Is there a way to detect each time the current cross zero that will turn the switch on during a small period of time?

Thanks!

 

[crutschow]

You could use a low power comparator to detect the zero voltage crossing.