TFPROBE01A - Omnipolar magnetic and reflective optical sensor probe

The sensor is designed for RPM measurement with TFRPM01 sensor board. The probe consists dual sensing technique - optical or magnetic. Therefore the user should select the one most suitable for the application.

This device was developed by ThunderFly s.r.o. and is published as OpenSource hardware with a GPLv3 license. It is commercially available, for a quote contact us by email at [email protected]. Or buy it directly together with a TFRPM01 sensor at Tindie store.

Magnetic Sensing

The magnetic Hall-effect sensor mounted on the probe board can sense both directions of the magnetic field. The strength of the magnetic field is a decisive parameter for the probe's correct function. The magnetic flux is expected to be perpendicular to the sensor PCB surface. The detailed requirements of magnetic flux density are described in AH3572 datasheet page 4.

In magnetic sensing, it is recommended to cover the probe in a black shrinking tube. The covering blocks function of a reflective sensor.

Optical Sensing

An optical sensor is sensitive to the infrared reflectance of material (usually a rotating disc with marks). To details see the VCNT2020 datasheet page 2

Hardware

TFPROBE01A is designed as Open-Hardware (GPL v3). All documentation is located in this repository.

The TFPROBE01 is sold and shipped without a soldered header, because its orientation may depend on the customer's use. Connecting cable and two headers (one straight and one right-angled) are included.

PCB

PCB dimensions

Optical and magnetic probe positions on PCB

Electronic schema

Full schema is available in PDF