A current measurement system comprising a multi-phase open loop current transducer for measuring phase currents (I.sub.1, I.sub.2, I.sub.3) flowing in a plurality n of primary conductors of a multi-phase electrical system. The transducer comprises a housing, a magnetic core including first and second core parts and a plurality n+1 of magnetic field detectors mounted in the housing between the first and second core parts in which portions of the primary conductors traversing the current transducer housing are positioned. The system further comprises a non-volatile memory in which information on at least one coupling matrix (K), pre-defined in a calibration procedure, is stored.

A current sensor according to the present invention includes a bus bar through which a measuring current flows; a nut with which the bus bar and an external terminal are brought into contact with and fastened to each other; a magnetic sensor capable of detecting a magnetic field generated when a current flows through the bus bar; a case member having a housing area in which the magnetic sensor is allowed to be housed, the case member sealing the bus bar and the nut inside; and a cover member provided over the housing area. The case member has an open part in which a portion of the nut is exposed. The open part is covered by an insulative protective member. Therefore, shavings generated when a bolt for fastening an external terminal is screwed into the nut are prevented from dropping to the outside of the current sensor.

A semiconductor device includes m power transistors (m is an integer of 2 or more) coupled in parallel each of which has a sense source terminal, a Kelvin terminal and a source terminal, a first average circuit that connects the first resistor and the second resistor in order between the sense source terminal and the Kelvin terminal and generates first to fourth average voltages and an arithmetic circuit that measures a first current value flowing through the sense source terminal from the first and second average voltages, measures a second current value flowing through the sense source terminal from the third and fourth average voltages and measures a current value flowing through the source terminal from the first to fourth average voltages and the first and second current values.

A current measuring device for detecting a current in an electric line includes: a housing; a fastening device arranged on the housing for fastening the housing to a supporting rail; and at least one magnetic field sensor. The housing has a first housing part and a second housing part which together form an accommodating device for accommodating an electric line between the first and second housing parts. The first and second housing parts are separable from one another in order to place an electric line onto the current measuring device and placeable onto one another in order to accommodate the electric line in the accommodating device between the first and second housing parts. The at least one magnetic field sensor detects a magnetic field on the electric line accommodated in the accommodating device.

Provided are methods and systems for testing time parameters of an adaptor and systems. The method includes the following. After a testing system is coupled with an adaptor, a clock signal is received from the adaptor, where the clock signal is indicative of the transmission time of the instruction. A first valid interrupt of the clock signal, a square wave corresponding to the first valid interrupt, and a next valid interrupt of the first valid interrupt are acquired. A first falling edge and a first rising edge of the first valid interrupt, a second falling edge of the square wave, and a third falling edge of the next valid interrupt are acquired. A test result time parameters of the adaptor is generated according to the first falling edge, the first rising edge, the second falling edge, and the third falling edge.

A high-lift shielded permanent magnet multistage water pump includes a pump shell, a motor assembly and an impeller. The motor assembly includes a motor barrel, a stator, a rotor and a rotor shaft. The pump shell is sleeved on an outside of motor barrel. An upper and a lower connection base for fixing the motor barrel is provided in the pump shell. A waterway cavity is formed between the pump shell and motor barrel. An upper and a lower impeller cavities are respectively formed at an upper and a lower ends of the pump shell. The lower impeller cavity, water passing cavity and upper impeller cavity are in sequential fluid communication. Both ends of the rotor shaft with an axel provided on pass through the upper and the lower connection bases respectively. The impeller is a multistage structure and mounted on the axle at both ends respectively.

A magneto-optical sensor for sensing a current flowing through a conductor includes a light source capable of providing a linearly-polarised optical beam, and a polarisation analyser configured to perform a differential measurement of two polarisation components of the linearly-polarised optical beam having travelled along an optical path arranged between the light source and the polarisation analyser. The optical path forms a closed trajectory around the conductor. The sensor comprises a cell containing an atomic gas arranged along the optical path.

An instrumented electric power voltage arrester includes a temperature sensor, wireless transmitter, and a visual over-temperature indicator. A disk shaped module, a replacement varister block, or a dummy block containing the sensor/transmitter is placed between varister blocks inside the arrester housing. A strap-on module is attached to the outside of the arrester housing. The sensor/transmitter utilizes a harvesting power supply that draws electric power for the electronics from the power line protected by the arrester. An ambient temperature sensor may be utilized to enhance accuracy. The temperature sensor/transmitter typically sends arrester monitoring data wirelessly to an RTU or handheld unit located outside the arrester, which relays the monitoring data to an operations control center that scheduled replacement of the arrester based on the monitoring data. A surge counter keeps track of the number of equipment and lightning related temperature surges experienced by the arrester.

A current sensing device includes a housing with a head adapted for releasably holding a wire of an electrical circuit without breaking the electrical circuit. The head has one or more current sensors configured to sense direct current in the wire without breaking the electrical circuit. The housing includes an alarm to indicate if the current sensing device senses a current in the electrical wire above a predefined threshold current. The head has a clip base and clip member that form an internal channel to closely receive the electrical wire and to releasably hold the electrical wire for testing. In some embodiments, the head has an internal channel that intersects the outer surface of the head and forms a longitudinal opening to allow insertion of the wire into the internal channel. The current sensing device has a processor programed to calibrate the current sensing device to compensate for electrical noise.

Current measurement devices for printed circuit board mounting are disclosed herein. The current measurement devices include a hollow and flexible core to improve response to a primary signal and decrease weight. The current measurement device includes a housing with guides to maintain alignment of the core. An electromagnetic shield may be placed between the circumference of the core and the housing. The housing may include apertures to facilitate washing. The current measurement device may include a primary conductor external to the housing.