Danisense has launched a precision series of PCB-mount current transducers for isolated DC and AC current measurement up to 72A.

Called DP, maximum linearity error is 10ppm and measurement resistance is up to 100Ω at full scale.

They use the company’s closed-loop, compensated flux-gate technology (see below) with a fixed excitation frequency and second-harmonic zero flux detection.

Devices are programmable for 12,5A, 25A, or 50A use through PCB tracking.

Vital statistics are 64.9 x 60 x 32mm high and 250g – suiting them to use in 1U power supplies, according to the company.

“Our technology has enabled us to deliver a PCB-mount current transducer with stability and accuracy,” said company marketing director Loic Moreau. “Its small size and low weight make it possible to include such high-performance measurement functionality on the PCB for the first time.”

Applications are foreseen in particle accelerators, stable power supplies, precision drives, battery testing,  power measurement and power analysis.

danisense-fluxgateHow this flux-gate works

The Danisense current sensor is based on a closed-loop system, with a flux gate sensing the magnetic field.

In the toroid, the magnetic field is generated by the primary current (Ip) and counteracted by the compensating secondary current (Is) generated by the integrator.

The flux gate detects magnetic fields in the toroid from DC to less than 100Hz at sub-ppm levels and tells the integrator to compensate them out.

At higher frequencies, the feedback winding (Nfb) detects magnetic fields in the toroid at ppm levels and tells the integrator to compensate them out as well.

The secondary current (Is) is therefore proportional to the primary current (Ip) with the ratio Np:Ns