GMW Associates is now offering a new addition to the Danfysik ULTRASTAB Current Transducer product range for ohmically isolated, precision measurement of electric current.
Operating on the principle of maintaining zero magnetic flux in a toroidal core, the 867-400 has a precise 2000:1 current ratio with an output of ±200mA for a ±400A primary current. The transfer linearity is better than 3ppm with a temperature coefficient of less than 0.3ppm/°C. Frequency response of the output current amplitude is from dc to 100kHz (-3dB) with a slew rate of ±200mA/16µs for a step change in primary current. Output current noise is less than 2ppm(rms) of full-scale from dc to 1kHz. Utilizing an appropriate external burden resistor enables voltage signal to be obtained e.g. ±1V full-scale with a 5 ohm burden resistor.
The 867-400 has a mechanical outline of approximately 76mm (3 inch) square by 43mm (1.7 inch) axial length with a large 26mm (1 inch) diameter central hole for the primary current conductor. A dual +15V, -15V (±5%), 250mA power supply is required.
Applications for the 867-400 include current control of particle accelerator corrector and focusing electromagnet power supplies, magnetic resonance imaging (MRI) gradient amplifiers, servo motor amplifiers and current measurement for precision power metering. Compared to resistive shunts or Hall effect current transducers the 867-400 provides greatly improved stability, lower common mode noise, much better linearity, reduced hysteresis and enhanced frequency response.