Thanks, we have a common mode problem, but have little room for adding Y capacitors across the transformers, as well as the ones we already have in the AC mains filter part. Also, we have no room in the bobbins of our transformers for any shield windings. Also, its too expensive to connect the ferrite core of the transformer to a quiet node.
We dont have any more room to increase the size of the common mode choke and Y capacitors, or add a second common mode choke.
We want to put a thermal pad to insulate the FET heatsink from the FET drain, but again, its more expense on an already tight budget.
We'd also like to space apart our AC mains filter components to limit coupling of emissions round the common mode choke etc, but we dont have the money to be able to increase baord size to do this.
Also, the added expense of twisting the wires off to the LED bank is yet another assembly cost, we'd rather see if we can get a pass with them untwisted, though we expect to be pulled up on this one.
Also, we’d like to bring over a suitably insulated and protected earthing wire across from the earth connection on the primary side of the PCB to the secondary, but again, its too expensive.