Hall effect sensors

Current distribution studies have also been used to develop optimal loading gradients for compounds within a PEM fuel cell. Santis et al.174 utilized a segmented plate design with Hall-effect sensors... 

Cam and crank sensors are classified by the type of sensing element MRE (fer-romagnetoresistive effect) sensor, Hall (Hall effect) sensor, and MPU (magnetic pick-up coil) sensor. Tab. 7.10.1 provides a summary of the principles and characteristics of the cam and crank sensors according to which element is employed [2],... 

There are various magnetic-field sensors on the market. A Hall-effect sensor measures magnetic-flux density B perpendicular to its plane (Fig. 7.11.14). In one direction a constant current flows through the Hall-effect sensor. The external magnetic-flux density B creates a proportional voltage t/Haii- Various Hall-effect sensors are on the market, mostly with an evaluation circuit to deliver a digital output. 

Small outline transistor (SOT), a plastic leaded package originally for diodes and transistors but also used for some ICs (such as Hall effect sensors). Some common sizes are SOT-23, SOT-26, SOT-223, and the very small SOT-523. 

Electrical tachometer Hall effect sensor Capacitive transducer... 

The wheel speed is calculated based on the input from a Hall Effect sensor. Such a sensor may produce a sine wave signal with a frequency that is proportional to the rotational speed of the wheel, as depicted in Fig. 8. 

The result of applying the oscillation fault model may vary depending on the implementation of the Hall Effect sensor signal conditioner. In our implementation, we assume that the number of zero crossings will increase as an effect of oscillations superimposed on the Hall Effect sensor signal, as shown in Fig. 9. This will cause the estimated wheel speed to be higher than the actual wheel speed (154 RPM in Fig. 9 instead of 98 RPM in Fig. 8). Since we inject faults directly into the behavior model, which takes the estimated wheel speed as input, we use the offset fault model to represent an oscillation superimposed on the Hall Effect sensor signal. 

Obviously, the switching of the current must be synchronised with the position of the rotor. This is done using sensors. These are often Hall-effect sensors that use the magnetism of the rotor to sense its position, but optical sensors are also used. 

Small Hall-effect sensors are widely used in conjunction with small magnets as proximity detectors in door and window alarms in security systems and have replaced the old breaker points in automotive ignition systems. They can also be used as ammeters to measure current flow in wires. 

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