Patent attributes
A circuit for an Intelligent Electrical device (IED) is disclosed. Using this circuit, the IEDs can be used in harsh industrial environments, such as those present in power utility substations. The circuit may comprise a dual stage isolated power supply. The dual stage isolated power supply has a first DC to DC converter for converting received power from the received voltage to an intermediate voltage. The intermediate voltage is then further converted to a voltage which can be used by the Ethernet IED. Each of the DC to DC converters also provide galvanic isolation and also transient suppression and electromagnetic interference filtering to decrease adverse electrical effects which may be inherent in the power received from an external source. The first and second DC to DC converter provides a first level of galvanic isolation which is greater than the second level of galvanic isolation provided by the second DC to DC converter. A third level of isolation is provided at each port of each IED to protect the internal components of the IEDs from other IEDs connected to it. The circuit can be used in any IED, such as Ethernet switches.