Magnetic Sensor With Error Detection Circuit
Original Publication Date: 1988-Jan-01
Included in the Prior Art Database: 2005-Feb-14
In a magnetic sensor for the bill recognition device of banking terminals, a circuit is provided for the detection of an extraneous substance, such as a paper clip, pin or staple, sticking to the magnetic sensor and to alert the operator to remove it so that erroneous bill recognition due to the extraneous substance can be prevented. Referring to the drawing, the magnetic sensor 1 of two serially- connected magneto-resistance elements are combined with two resistance elements to form a bridge circuit. In this circuit, the resistance elements are accurately adjusted by making the function trimming so that a DC factor of the sensor output can be completely cancelled.