Hi, I have an application, where I need to sense AC current imbalance between two lines. Perfect application for a CBCT. The wires themselves carry a reasonably high voltage (at moments, in excess of 3KV), so my 'prototype', has a Teflon block going through the transformer, with the two wires positioned in this (giving both good position stability, and insulation). Now, my problem is the size of the CBCT. There are readily available toroids, with hole sizes from perhaps 35mm and up. However I have a height limit over the board, which is making this unuseable. What I'd like to find, is something like a rectangular CBCT, with a central hole perhaps
25mm wide, and a relatively low total height (not exceeding 50mm to the top of the winding), that is available 'off the shelf' (the run size is small, so doesn't warrant a custom transformer). Perhaps 500:1 ratio (though the circuit can be adjusted to handle a wide tolerance here), and peak current rating doesn't need to exceed 1A. I am in the UK, so a UK source would be preferred. Searches of the normal component manufacturers find lots of larger toroids, and a few rectangular designs, and a general Google search, gives lots of companies able to make custom units, but nothing visible 'off the shelf'. So, has anyone any pointers to a supplier stocking items like this?.Many thanks in advance.