Phares Electronics Digital Output Hall Effect Sensors are simple on/off non-contact switching devices. Digital output signal is clean, fast and switched without bounce – an inherent problem with mechanical contact switches. They are magnetically activated switches that detect the motion, position, or change in field strength of an electromagnet, a permanent magnet, or a ferromagnetic material with an applied magnetic bias. The digital output is a square-wave signal that is directly proportional to the input (linear). The digital output signal is ideal for logic inputs (PLC/DCS) and other devices that can measure frequency directly. This includes our Tachometers and Remote Zero Speed Switch. A pull up resistor may or may not be needed depending on the logic input or device. Our Hall Effect Sensors are compatible with all digital families. They provide reliable, repetitive operation in close tolerance applications. They are more efficient and effective than inductive or optoelectronic sensors as they are virtually immune to environmental contaminants and are suitable for use under severe service conditions. Our Hall Effect Sensors can see precisely through dirt and darkness.