Vigortronix 230v toroidal transformers single primary dual secondary vigortronix vtx 146 015 106 toroidal transformer open style 15va 230v ac primary winding 2x 0 6v ac secondary windings 150mm lead length ul csa tuv en60950en60065 compliant vigortronix vtx 146 015 106 toroidal transformer 230v single primary 15va 0 6v 0