An apparatus includes a magnetizing circuit configured to be coupled to a transformer and to selectively provide a magnetizing current to the transformer and a control circuit configured to cause the magnetizing circuit to provide the magnetizing current following disconnection of the primary winding of the transformer from the power source. The magnetizing circuit may be configured to provide the magnetizing current from a first source following disconnection of the primary winding from a second source. The transformer may include a first transformer and the apparatus may further include a second, higher impedance transformer coupled between the second source and the first transformer. In further embodiments, the magnetizing circuit may include a solid-state converter.