A campaign for a current probe called Little Bee was launched on Crowdsupply. Little Bee is an affordable and high-performance current probe and magnetic field probe that enables you to debug and analyze electronic devices more effectively. This device comes in handy because current probes available today are expensive, therefore having a limited number of users. Current probes are gaining ground today because of the popularity of power electronics like electric vehicles, alternative energy, and high-efficiency power supplies. Regarding the aim of the project, the company says:
We hope to make the world of power electronics accessible to more people by delivering a much-needed piece of test equipment as open hardware and at an affordable price.
Little Bee can function as a traditional current probe, providing isolated measurements of the current in a wire with higher accuracy, and It can also measure currents over a wide bandwidth: from DC to the MHz range. Thanks to its Anisotropic Magneto-Resistive (AMR) magnetic sensor, Little Bee’s performance can be compared to other current probes based on fluxgate magnetometers, and probes with hybrid features that offer AC current transformers with DC hall effect sensors. Little Bee offers the same level of performance, but with a much lower cost.
The AMR sensor functions by sensing magnetic fields, producing a voltage proportional to the magnetic field strength. It features a clip, which enables current sensing by translating the current in a wire into a magnetic field. It is also equipped with a ferrite toroid with an air gap in which the sensor tip rests. The synergy between the current in the wire and the magnetic field in the air gap varies little as the wire moves around the center of the toroid. This enables accurate current sensing despite variations in the test setup.