Aim-TTi has launched an innovative current probe designed to measure currents in PCB tracks. The Aim I-prober 520 ‘positional current probe’ uses patented technology to measure current in a conductor without requiring the conductor to pass through the probe or flow through a shunt resistor, as with conventional methods.
The current probe operates by sensing the magnetic field very close to the track. The distance between the track and the sensing element must be very small to achieve good sensitivity, because the field strength decreases with the square of the distance. To create a practical current probe, the I-prober 520 utilises a patented miniaturised fluxgate magnetometer developed in conjunction with Cambridge University (UK). The miniature device also has much lower noise and much wider bandwidth than conventional fluxgate magnetometers.
The I-prober 520 is a compact hand-held probe for use with an oscilloscope. When the insulated probe tip is placed on a PCB track, the current flowing in the track can be sensed and measured. The probe has a bandwidth of DC to 5 MHz and a dynamic range of 10 mA to 20 A peak to peak. It is safety rated at 300 V Cat II (600 V Cat I) and is suitable for connection to any oscilloscope.
As well as measuring current in PCB tracks, the probe can be used on component leads or any other current-carrying conductors. Another interesting use is measuring currents in ground planes, where it can detect circulating currents, interference injection points and 'hot spots' in order to optimise designs.
The Aim I-prober 520 is supplied with a control box and calibrator, power supply, and a clip-on toroid assembly for conversion into a conventional closed magnetic loop current probe.