LEM Products

Selecting the right LEM current transducer involves considering several key factors: current range (choose 20-30% higher than maximum expected current), accuracy requirements (0.1-0.5% for closed-loop, 1-2% for open-loop), bandwidth needs (100-200kHz for closed-loop, 10-50kHz for open-loop), environmental conditions (temperature range, vibration, EMC), mounting constraints (panel, PCB, or busbar mount), and output type (voltage or current). For automotive applications, ensure AEC-Q100 qualification. Contact our FAE team for personalized selection guidance based on your specific requirements.

If you need high precision (better than 1%), choose closed-loop sensors like CAS or HAIS series. For cost-sensitive applications where 1-2% accuracy is sufficient, open-loop sensors like HLSR series are ideal. For automotive EV applications, select AEC-Q100 qualified sensors from HO or HMSR series.

Open-loop Hall sensors measure magnetic field directly using a Hall element, offering simple structure, lower cost, and smaller size. They typically provide 1-2% accuracy with 10-50kHz bandwidth, suitable for general industrial applications. Closed-loop Hall sensors use a compensation coil and feedback mechanism to null the magnetic field, achieving 0.1-0.5% accuracy with 100-200kHz bandwidth. Closed-loop sensors have better linearity, lower temperature drift, and faster response but are larger, more expensive, and consume more power. The choice depends on your accuracy requirements, budget, and application constraints.

Choose open-loop sensors (HLSR series) for cost-sensitive applications like HVAC, lighting control, and general motor monitoring. Choose closed-loop sensors (CAS, HAIS, HO series) for precision applications like servo drives, power analyzers, medical equipment, and EV battery management where accuracy is critical.

Yes, LEM Hall effect current transducers can measure both DC and AC currents. The Hall effect principle responds to the magnetic field generated by current flow, regardless of whether it's DC or AC. For DC measurement, the sensor provides a stable output proportional to the DC current. For AC measurement, the sensor accurately tracks sinusoidal and non-sinusoidal waveforms. The bandwidth specification indicates the maximum AC frequency the sensor can accurately measure - typically 10-50kHz for open-loop and 100-200kHz for closed-loop sensors. Some LEM models can also measure complex waveforms including PWM signals common in motor drives and inverters.

All LEM current transducers measure both DC and AC. For pure DC applications like battery monitoring, any LEM sensor will work. For AC applications, consider the bandwidth requirement - standard 50/60Hz power monitoring works with any sensor, while high-frequency PWM applications need higher bandwidth closed-loop sensors.

LEM current transducers provide galvanic isolation between primary (measured) and secondary (output) circuits. Standard industrial models typically offer 2.5kV to 6kV isolation voltage (RMS), tested according to IEC 61010-1 standards. High-voltage models can provide up to 12kV isolation for specialized applications. The isolation ensures safety by preventing high voltages from reaching low-voltage control circuits and eliminates ground loop issues. All LEM sensors undergo 100% production testing for dielectric withstand voltage. For EV applications, 3kV to 5kV isolation is standard for high-voltage battery systems.

For standard industrial applications (up to 600V systems), 2.5kV isolation is sufficient. For high-voltage EV battery systems (400V-800V), select sensors with 3kV or higher isolation. For grid-tied applications or medium-voltage systems, consider sensors with 5kV or higher isolation ratings.

As an authorized LEM distributor, BeiLuo Electronics offers multiple ways to purchase: 1) Contact our sales team directly via phone or email for quotations; 2) Submit an inquiry through our website contact form; 3) Send a purchase order to our sales department. We maintain stock of popular LEM models for fast delivery and can schedule deliveries for production programs. For large volume orders, we offer competitive pricing and flexible payment terms. Our minimum order quantity (MOQ) varies by product - standard industrial sensors typically have MOQ of 5-10 pieces, while automotive sensors may require 50-100 pieces. Contact us for specific pricing and availability.

For prototype and small quantity needs (1-10 pieces), contact us for stock availability and pricing. For production volumes, we recommend establishing a scheduled order agreement for better pricing and supply security. For automotive programs, contact our automotive sales team early in the design phase for PPAP support and long-term supply agreements.