Aimed at instrumentation applications, the SPCT-250 and SPCT-251 printed circuit board mount, current-sense transformers have outputs that vary based on the termination or loading resistor on the secondary winding. When a single turn is inserted through the window area of the transformers, the resulting turns ratio of 2,000:1 allows the output to be calculated based on the input current.With an input current ranging from 0 to 20A, output voltage tolerances vary based on the load resistor. Typically this variance falls within a range from 3% to 8%. The transformers are constructed with standard laminations and a three-flange bobbin and have an open section within the window area that accommodates insulated conductors up to 0.16" in diameter. They measure 1" x 0.92" x 8.825" and have a HIPOT rating from the secondary winding to the core of 1,500 Vac. Pricing for the SPCT-250 and SPCT-25 is $1.75 and $2.21, respectively, with delivery from stock to eight weeks.