The POW-24V power supply is designed differently from a general purpose power supply. Emphasis is placed on withstanding and rejecting EMI events, such as transients associated with close-by unsnubbered contactors etc. This is achieved by:

• Second and third stage filtering in both common and normal mode configurations
• Constructing the transformer with inherent shielding to reject unwanted signals

This combination of techniques eliminates the need for a Y cap between the primary and secondary, increasing the impedance to high frequency transients by an order of magnitude or more.