A probe unit according to the present invention is suitable for allowing a large current to flow. In the probe unit that accommodates a plurality of contact probes for electrically connecting an inspection target object and a signal processing device used to output an inspection signal, both ends of a large current probe (3) are electrically connected to electrodes of a contact target object, and a large current is made to flow via a metal block (50) that comes into contact with both end portions of the large current probe (3).

An apparatus for processing a signal by means of electromagnetic waves according to one embodiment of the present invention can, when a radio frequency (RF) signal is radiated onto a medium through any one of a plurality of channels, simultaneously receive the radiated RF signals which have been reflected or scattered by the medium or have penetrated the medium through the plurality of channels other than the channel through which the RF signal has been radiated.

A wafer test machine is disclosed. The wafer test machine comprises a main body having a chamber defined therein, wherein a probe card is disposed at an upper portion of the chamber; a chuck for fixing a wafer in the chamber; a moving unit for moving the chuck in the chamber, thus making a contact between the probe card and the wafer; and a laser cleaning apparatus for cleaning the probe card in the chamber using a laser beam, when the probe card does not contact the wafer.

A workpiece evaluating method evaluates the gettering property of a device wafer having a plurality of devices formed on the front side of the wafer and having a gettering layer formed inside the wafer. The method includes the steps of applying excitation light for exciting a carrier to the wafer, applying microwaves to a light applied area where the excitation light is applied and also to an area other than the light applied area, measuring the intensity of the microwaves reflected from the light applied area and from the area other than the light applied area, subtracting the intensity of the microwaves reflected from the area other than the light applied area from the intensity of the microwaves reflected from the light applied area to thereby obtain a differential signal, and determining the gettering property of the gettering layer according to the intensity of the differential signal obtained above.

To provide a magnetic sensor circuit which does not output spike-like voltage errors to a signal processing circuit. A magnetic sensor circuit is provided which is configured so as to output an output signal to a signal processing circuit through a plurality of hall elements driven by a first switch circuit and a second switch circuit controlled by a second control circuit and in which the first switch circuit controls timings at which spikes occur in the output signal of each of the hall elements in such a manner that the timings are not the same, and the second switch circuit selects and outputs an output signal having a period of a timing free of the occurrence of a spike.

The various embodiment of the present disclosure provides a system to define and identify an absolute mechanical reference position for a rotating element, The system comprises a radial ring magnet comprising plurality of pole pairs mounted to the rotating element, a first magnetic sensor in proximity of the radial ring magnet to detect angular position of said rotating element, at least one second magnetic sensor in proximity of the radial ring magnet to detect the passage of each of the pole pair and a control module adapted to define said absolute mechanical position by computing a unique first set of feature values for each of said plurality of pole pairs based on responses of said first magnetic sensor and said second magnetic sensor. The first set of feature values is stored in a memory unit.

An assembly including an insulated gate bipolar transistor (IGBT) is provided. The IGBT is coupled with a gate driver for receiving a gating signal to drive the IGBT and providing a feedback signal of the IGBT which indicates a change of a collector-emitter voltage of the IGBT. The assembly further includes a failure mode detection unit for determining whether the IGBT is faulted based on a timing sequence of the gating signal and feedback signal. The failure mode detection unit is capable of differentiating fault types including a gate driver fault, a failed turn-on fault, a short-circuit fault, a turn-on over-voltage fault and a turn-off over-voltage fault. Accordingly, an IGBT failure mode detection method is also provided.

Electrical current transducer (2) of a closed-loop type for measuring a primary current (I.sub.p) flowing in a primary conductor (1), comprising a fluxgate measuring head (7) and an electronic circuit (16) including a microprocessor (18) for digital signal processing. The measuring head includes a secondary coil (6) and a fluxgate detector (4) comprising an excitation coil and a magnetic material core. The electronic circuit comprises an excitation coil drive circuit (14) configured to generate an alternating excitation voltage to supply the excitation coil with an alternating excitation current (I.sub.fx), the secondary coil (6) connected in a feedback loop (12) of the electronic circuit to the excitation coil drive circuit (14), the electronic circuit further comprising a ripple compensation circuit (26, 28) configured to compensate for a ripple signal generated by the alternating excitation voltage.

A position sensor connected to first and second electric signal sources to output a first electric signal with a first frequency and a second electric signal with a second frequency. The position sensor includes: a primary coil generating a magnetic alternating field with the first frequency; a first and a second secondary coil, the first and second secondary coils each magnetically coupled to the primary coil by the position transmitter, and third and fourth electric signals induced in the first and second secondary coils respectively by the generated magnetic alternating field; a frequency converter converts the third and fourth electric signals into respective first and second intermediate frequency signals, the frequency converter connectable to the second electric signal source. A Goertzel filter bank demodulates the first intermediate frequency signal to obtain a first demodulated signal and demodulates the second intermediate frequency signal to obtain a second demodulated signal.

A conductive probe may include a probe body for communicating with a circuit tester or a jumper. The probe body may be formed of metal and may have a free end. A probe tip may be mounted to the end of the probe body. The probe tip may be formed of thorium-tungsten. The probe tip may be configured for contacting a circuit node.