A magnetic sensor whose output characteristic is less sensitive to the environmental temperature is provided. Magnetic sensor 1 has free layer 24 whose magnetization direction changes in response to an external magnetic field, pinned layer 22 whose magnetization direction is fixed with respect to the external magnetic field, spacer layer 23 that is located between pinned layer 22 and free layer 24 and that exhibits a magnetoresistance effect, and at least one magnet film 25 that is disposed on a lateral side of free layer 24 and that applies a bias magnetic field to free layer 24. A relationship of 0.7 ≤T.sub.C_HM/T.sub.C_FL≤1.05 is satisfied, where T.sub.C_HM is Curie temperature of the magnet film, and T.sub.C_FL is Curie temperature of the free layer.

A system is provided for detecting a radio frequency signal. The system includes a dielectric platform, a first SQUID array, a second array of SQUIDs and a processing component. The dielectric platform has a first planar surface and a second planar surface that is disposed at an angle relative to the first planar surface. The first array of SQUIDs is disposed on the first planar surface and can output a first detection signal based on the radio frequency signal. The second array of SQUIDs is disposed on the second planar surface and can output a second detection signal based on the radio frequency signal. The processing component can determine a first plane from which the radio frequency signal is transmitting based on the first detection signal and the second detection signal.

A sensor output compensation circuit includes a linearity compensation circuit to adjust linearity of a sensor output by changing a resistance value of a first variable resistor, a compensation circuit to adjust sensitivity temperature characteristics of a sensor output by changing a resistance value of a second variable resistor, and a compensation circuit to adjust temperature characteristics of an offset voltage of the sensor output by inputting a reference voltage to a reference voltage terminal of an operational amplifier of an amplifier circuit for compensation.

An electronic system for a surgical instrument is disclosed. The electronic system comprises a main power supply circuit configured to supply electrical power to a primary circuit. A supplementary power supply circuit configured to supply electrical power to a secondary circuit. A short circuit protection circuit coupled between the main power supply circuit and the supplementary power supply circuit. The supplementary power supply circuit is configured to isolate itself from the main power supply circuit when the supplementary power supply circuit detects a short circuit condition at the secondary circuit. The supplementary power supply circuit is configured to rejoin the main power supply circuit and supply power to the secondary circuit, when the short circuit condition is remedied.

An electronic system for a surgical instrument is disclosed. The electronic system comprises a main power supply circuit configured to supply electrical power to a primary circuit. A supplementary power supply circuit configured to supply electrical power to a secondary circuit. A short circuit protection circuit coupled between the main power supply circuit and the supplementary power supply circuit. The supplementary power supply circuit is configured to isolate itself from the main power supply circuit when the supplementary power supply circuit detects a short circuit condition at the secondary circuit. The supplementary power supply circuit is configured to rejoin the main power supply circuit and supply power to the secondary circuit, when the short circuit condition is remedied.

A magnetic measuring apparatus includes an inclination gantry including a mount surface and an inclined surface that is inclined with respect to the mount surface, a cryostat disposed on the inclined surface, a cryocooling system connected to the cryostat, a sensor tube connected to the cryostat and including a curved surface that does not curve in a predetermined direction and curves in a direction orthogonal to the predetermined direction such that a center of the curved surface protrudes with respect to side edges of the curved surface, and a magnetic sensor that measures biomagnetism and is housed in the sensor tube such that a sensor surface of the magnetic sensor faces the curved surface. The sensor surface is inclined with respect to the mount surface in a direction that is the same as a direction in which the inclined surface is inclined.

A compensation circuit receives a sensing signal from a Hall sensor and outputs a compensated Hall sensing signal. The compensation circuit has a gain that is inversely proportional to Hall sensor drift mobility. The compensated Hall sensing signal is temperature-compensated.

A Hall sensor compensation circuit includes an input node configured for receiving a bias signal for a Hall sensor. A bias node provides to the Hall sensor a compensated bias signal. A compensation network coupled between the input node and the bias node has a gain inversely proportional to Hall mobility, .sub.n, wherein the Hall sensing signal is temperature-compensated.

A circuit has a magnetic sensor that produces an uncompensated magnetic sensor output signal. A temperature sensor produces an ambient temperature signal. A compensation circuit is connected to the magnetic sensor and the temperature sensor. The compensation circuit is configured to add a computed temperature compensation signal to the uncompensated magnetic sensor output signal to produce a magnetic sensor temperature compensated output signal that reduces thermally induced variation of the uncompensated magnetic sensor output signal.

A calibration apparatus for calibrating a magnetic sensor configured to generate an output signal indicative of magnetic field strength when a bias signal is applied to it is disclosed. The apparatus includes a test magnetic field generator (MFG) to generate magnetic fields of known magnitude, and further includes a processor to control the MFG to generate a known magnetic field, control the sensor to generate a test output signal when the MFG generates the known magnetic field and a known bias signal is applied to the sensor, and determine how to change the bias signal based on a deviation of the measured test output signal from an expected output signal. Using a test MFG that produces known magnetic fields when known bias signals are applied to sensors allows evaluating and compensating for changes in sensitivity of the sensors by accordingly changing bias signals applied to the sensors.