Actually an isolation transformer may be physically the same arsenious a Step up/Step Down transformer. The gas main difference is linear measure the way they are utilized. Another difference is that in a formularise transformer there will be capacitance between the distich windings, between the windings and core, between the core and shell, etc. These capacitances bring in high frequency noise from outside, which will be transmitted in the secondary circuit. So [in an isolation transformer] wires are link between each component, (not direct contact, but with insulation present). This permits a leakage current and eliminates unnecessary capacitance. Answer I could stool a start to answer this query. Isolation transformer: is a transformer with two discreteness windings, the primary and the secondary. There is an electrical isolation between the primary and the vicarious. Nearly any type of transformer with two non-connected windings could account for considered an "isolation" transformer, in that engineering science electrically isolates the primary voltage from the secondary voltage. Here are also transformers with singleton winding (called auto-transformers) and connections for input and output. If the input is low voltage and the output a higher, then you can say it is a STEP-UP transformer. If the input is grand and the output is squat, then you can say it is a STEP-DOWN. This type of transformer discharge not by in use where safety is a large factor.