I have a school project that implements a digital electronics power converter. It will be a current controller. The power source is also voltage controlled using a commercial power converter. The voltage controller switches at about 20 KHz. The current drawn from the power source must be sampled.

Is the LEM LAH 50-P current transducer able to satisfy the requirements? It has a step response time of under 500 ns (2MHz). If the voltage controller is switching at 20 KHz, can the current be sampled at 40 KHz?

Is the following the correct mode of operation? :

Place the sensor in series with the power line (breaking the line by connecting one end to the in terminals and the other to the out terminals). Then connecting 12 to 15 V to the Uc terminals.

I would be mostly guessing after that. Can someone explain?enter image description here enter image description hereenter image description here


The LEM device requires a dual polarity power supply. You need to supply +15V with to the +Uc terminal with the 0V terminal connected to the power supply common terminal. You need to supply -15V to the -Uc terminal. Connect the power line as you described. The current in Rm will have the same waveform as the power line current but reduced in amplitude by a factor of 2000. You can use as input to your sampling circuit, the voltage across that resistor, that you must supply.


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