A circuit for servicing a load connectable with a power supply, the circuit comprising: a plurality of three-terminal switches that define a series conduction path connectable between the power supply and the load, the series conduction path comprising a source terminal and a drain terminal of each of the plurality of three-terminal switches; one control supply in connection between a gate terminal of each of the plurality of three-terminal switches and a source terminal of each of the plurality of three-terminal switches, the control supply productive of a control voltage; a plurality of isolator circuits corresponding to the plurality of three-terminal switches, and each disposed in connection between the one control supply and a source terminal and a gate terminal of each of the three-terminal switches of the plurality of three-terminal switches and comprising a transformer which transforms the control voltage received from the one control supply at the respective three terminal switch (220, 225, 230) into a specified voltage to close the respective three terminal switch (220, 225, 230) and each of the plurality of three-terminal switches is responsive to the control voltage at its respective gate terminal, thereby closing a connection between the respective source terminal and respective drain terminal of each of the plurality of three-terminal switches based on the specified voltage; and a controller in signal communication with the control supply; wherein each of isolator circuit comprises: a logic circuit in connection with the control supply and in signal communication with the controller; the transformer in connection with the logic circuit; a rectifier in connection with the transformer; and a tuning circuit in connection with the rectifier and the source terminal and the gate terminal of the three-terminal switch. a plurality of three-terminal switches that define a series conduction path connectable between the power supply and the load, the series conduction path comprising a source terminal and a drain terminal of each of the plurality of three-terminal switches; one control supply in connection between a gate terminal of each of the plurality of three-terminal switches and a source terminal of each of the plurality of three-terminal switches, the control supply productive of a control voltage; a plurality of isolator circuits corresponding to the plurality of three-terminal switches, and each disposed in connection between the one control supply and a source terminal and a gate terminal of each of the three-terminal switches of the plurality of three-terminal switches and comprising a transformer which transforms the control voltage received from the one control supply at the respective three terminal switch (220, 225, 230) into a specified voltage to close the respective three terminal switch (220, 225, 230) and each of the plurality of three-terminal switches is responsive to the control voltage at its respective gate terminal, thereby closing a connection between the respective source terminal and respective drain terminal of each of the plurality of three-terminal switches based on the specified voltage; and a controller in signal communication with the control supply; wherein each of isolator circuit comprises: a logic circuit in connection with the control supply and in signal communication with the controller; the transformer in connection with the logic circuit; a rectifier in connection with the transformer; and a tuning circuit in connection with the rectifier and the source terminal and the gate terminal of the three-terminal switch. a logic circuit in connection with the control supply and in signal communication with the controller; the transformer in connection with the logic circuit; a rectifier in connection with the transformer; and a tuning circuit in connection with the rectifier and the source terminal and the gate terminal of the three-terminal switch.