Hi Diver300 thanks for getting back. I dont know how to insert an image. i clicked on the insert button above but it needs a link. I am using a fan or a light bulb for a load. As my project specification I need to use an isolating transformer right at the very beginning just after the mains supply. My Question was do I really need to use a Current transformer even though I am using isolation at the mains, or can I just use passive components to sense current which has no insulation if you know what i mean