Patent ID: 8022802

Claim:
Sensor for measuring electrical parameters in a high voltage environment comprising a high voltage side ( 4 ) for connection to high voltage conductors, a low voltage side ( 6 ) for connection to low voltage power supply and measurement signal control circuitry, a measurement signal circuit ( 16 ), a power supply circuit ( 14 ), and at least one isolating transformer ( 18 , 20 ) for transmission of electrical power supply and/or measurement signals between the low voltage side and the high voltage side, wherein the isolating transformer comprises at least a first transformer core on a high voltage side and a second transformer core on a low voltage side, a first transformer coil on a circuit board around a first branch of the first transformer core and a second transformer coil on a circuit board around a second branch of the second transformer core on the low voltage side, the isolating transformer further comprising an intermediate coil encircling at least a second branch of said first transformer core and a first branch of said second transformer core.