By using it to detect a magnetic field, this OHS3140U Hall effect sensor from Optek Technology (TT electronics) can then act as a proximity switch, speed detector, or current sensor. This part can handle a current up to 25 mA. This device has a typical operating supply voltage of 5|9|12|15|18 V. This part has a minimum operating temperature of -40 °C and a maximum of 125 °C.