The Hall technology works contact-free as well. The difference compared to a reed switch is, however, that the magnetic field is continuously measured.
Where a reed switch switches binary only (0 or 1), a Hall chip can be used for distance measurement, for instance.
Hall sensors demand for an uninterrupted power supply to be able to provide an output voltage. Pre-condition for the Hall effect is that some electric current flows through the Hall sensor, with a perpendicular magnetic field above the chip. The output voltage is proportionate to the product of magnetic flux density and current.
The simplest way of application of a Hall sensor is a digital switch. A previously defined or programmed threshold value in the sensor is permanently compared to the effective magnetic field strength. The switching status at the output changes when this value is exceeded. This output voltage is switched on or off.
A linear Hall chip is used if a proportionate signal depending on the magnetic field is required. This chip does not adopt a discrete switching status but continuously emits an analogue voltage or a pulse-width modulated signal.
In special cases, field vectors have to be recorded by measurement of the sine and cosine component of the magnetic field. The components of the magnetic field are detected by the horizontal Hall element perpendicular to the chip surface. The data on angles and positions are directly emitted via a proportionate output signal.
– freely selectable Hall chip
– customizable enclosure