EI41 Low Frequency AC Isolation Step-Down Power Transformer for Home Appliances and Audio Equipment OEM Product Overview ZXY EI41 low frequency AC isolation step-down power transformer is engineered for household appliances and audio equipment. Constructed with high permeability silicon steel core and insulated copper wire, this transformer delivers reliable AC voltage step-down and galvanic isolation. We offer comprehensive OEM customization for turns ratio, output voltage,