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LEM SENSOR

 

LEM is a market leader in providing innovative and high quality solutions for measuring electrical parameters. Its core products – current and voltage transducers - are used in a broad range of applications in industrial, traction, energy and automotive markets. LEM’s strategy is to exploit the intrinsic strengths of its core business, and develop opportunities in new markets with new applications. Together with production plants in Geneva (Switzerland), Machida (Japan), Beijing, (China) and our regional sales offices, LEM offers a seamless worldwide service. LEM has been listed on the SIX Swiss Exchange since 1986. The company’sticker symbol is LEHN.
LEM is a mid size company with a global feel. We have 1100 employees worldwide.

Typical applications include

AC variable speed drives
Servo motor drives
Static converter for DC drives
Battery supplied applications
Uninterruptible power supplies (UPS)
Switched-mode power supplies (SMPS)
Power supplies for welding, medical, mobile telecom, etc.
Pumps & fans control/monitoring
Induction cooking
Gas co-generator
Elevators
Forklifts
Air conditioning and ventilation equipment
Various converters (solar, wind generators)
Grid power control
With more than 2,500 current and voltage transducers in our portfolio, LEM offers a comprehensive range of accurate, reliable and galvanically isolated devices to measure current from 0.1 A to 20,000 A and voltage from 10V to 6,400V, across a range of technologies. LEM transducers are CE marked in recognition of their electromagnetic compatibility and compliance to EMC standards. The reference standard is EN50178 to comply with electrical performances and environmental constraints.

Energy & Automation

Electrical signals are the power source for all manufacturing processes, machines and systems. In addition they enable the fast and reliable supervision of equipment and facilities. Integrated transducers from LEM take this a step further and provide your complete process with increased control and reactivity.
These applications are related to different end-user profiles:
Machine and panel builders
System integrators / engineering
Factory maintenance and safety services
Energy service companies and facility management
LEM integrated transducers combine advanced sensing technologies and signal conditioning of electronic circuits (True RMS, industry standard outputs e.g. 0-5/10 V or 4-20 mA, active energy calculation, threshold detection, specific failure detection, etc.) in addition to integration of communication functions.

Traction & Trackside

Isolated measurement of current, voltage and power 
Modes of public transport such as high-speed trains, city transit systems and freight trains provide the ideal solution to meet the increased demand for more mobility whilst helping to fight pollution and traffic congestion. Power electronics is essential to driving and controlling energy in these systems. New requirements are continuously emerging in the railway industry, such as the demand for energy measurement, track objects monitoring and a need to constantly improve maintenance infrastructures.

Typical applications of LEM products:

Mainconverterfor urban transportation systems(metros- trams – trolleybuses)
Track objects monitoring
Sub-stations
Inverters, converters, rectifiers
Auxiliary power units
Circuit breaker, for transformers, DC link
Control and safety systems
Energy metering
Rolling stock heavy traction, diesel electric
Mining trucks
A complete range of accurate, reliable and galvanically-isolated transducers for the measurement of current from 0.1A to 20,000A and voltage from 10V to 6,400V provides control and protection signals on-board as well as for trackside applications. LEM transducers are CE marked in recognition of their electromagnetic compatibility and their compliance to EMC standards. Their reference standard is EN 50155 for the electrical performance and environmental constraints as well as EN 50124-1 for creepage and clearance distances design versus the required insulation levels.

Automotive

LEM Automotive specializes in developing and manufacturing current transducers for battery management and motor drive applications in cars, buses and trucks. By controlling the current in energy-intensive applications, LEM participates in the global effort to reduce overall energy consumption.Typical applications for automotive transducers include:
Standard battery monitoring
Hybrid and EV battery pack current sensing
Fuel cell current control
DC/DC converters and AC/DC inverters
Hybrid and EV motor inverter drive
EPS and X-by-wire applications
LEM products meet all quality requirements for the automotive industry and comply with RoHS specifications. All our production and development centers are certified with ISO TS 16949 (in Switzerland and in China). Based on our deep knowledge of applications and current measurement technologies, LEM develops both catalog and customized products which can be perfectly tailored to meet your needs in terms of performance, space requirement and cost.

Closed Loop Hall Effect

The magnetic flux created by the primary current lp is balanced by a complementary flux produced by driving a current through the secondary windings. A hall device and associated electronic circuit are used to generate the secondary (compensating) current that is an exact representation of the primary current. Features:
Wide frequency range
Good overall accuracy
Fast response time
Low temperature drift
Excellent linearity
No insertion losses

Operation principle

A very small current limited by a series resistor is taken from the voltage to be measured and is driven through the primary coil. The magnetic flux created by the primary current IP is balanced by a complementary flux produced by driving a current through the secondary windings. A hall device and associated electronic circuit are used to generate the secondary (compensating) current that is an exact representation of the primary voltage. The primary resistor (R1) can be incorporated or not in the transducer.
Features:
Measurement of high voltages
Safety isolation
Good overall accuracy
Low temperature drift
Excellent linearity

Open Loop Hall Effect

The magnetic flux created by the primary current IP is concentrated in a magnetic circuit and measured in the air gap using a Hall device. The output from the Hall device is then signal conditioned to provide an exact representation of the primary current at the output.
Features:
Small package size
Extended measuring range
Reduced weight
Low power consumption
No insertion losses

Eta Operation principle

Eta technology combines elements from both the Open Loop (O/L) and Closed Loop principles. The result is a device that has the best balance between the features of the both operating principles. The O/L principle is found again for the DC current measurements and the transformer effect (one of the Closed Loop principles) is used for the AC current measurements.
Features:
Wide bandwidth
Extended measuring range
Very low power consumption
Unipolar power supply 0 ... + 5 V
Fast response time

C-Type Closed Loop

Type-C transducers are high accuracy, large bandwidth transducers which do not use Hall generators. This technology uses two toroidal cores and two secondary windings, and operates on the principle of compensating current from an internal generator. For voltage measurements, a very small current (few mA's) is taken from the voltage line to be measured and is driven through the primary coil. The primary resistor is incorporated inside the transducer.
Features :
High accuracy
Very wide frequency range
Reduced temperature drift
Excellent linearity
Measurement of differential currents (CD)
Safety isolation (CV) )
Reduced consumption on the primary (CV)

IT-Type Closed Loop (CSC)

IT current transducers are high accuracy, large bandwidth transducers which do not use Hall generators. The magnetic flux created by the primary current (lp) is compensated by a secondary current. The zero-flux detector is a symmetry detector using two wounded cores connected to a square-wave generator. The secondary compensating current is an exact representation of the primary current.

 

Features:
Very high global accuracy
Very low noise on the output signal
Linearity < 1 ppm
Low cross-over distortion
High temperature stability
Wide frequency range

Isolation Amplifier (CSC)

To measure voltage (Vp), the AV 100 series uses only well known electronic components, the main one being an isolation amplifier. The voltage to measure (Vp) is directly applied on the transducer primary connections through an internal resistor network and some components allowing the signal to feed an isolation amplifier. An isolated signal is recovered and then conditioned in order to supply a current at the transducer output connections, which is an exact representation of the primary voltage.
Features:
Any kind of signal, DC, AC, pulsed and complex can be measured
Galvanic isolation between primary (high power) and secondary circuits (electronic circuit)
Short dynamic response for a good frequency bandwidth
Fast response time
Small volume needed

 

 

The Company We Serve

合作企业
臻迪科技

The Company We Serve

合作企业
臻迪科技