How to read large current values into the DAQ 6025E?

[Kostya 74]

Hello,

How to read large current values into the DAQ 6025E? I have an active load (resistance) in my electric circuit, through which I put an electric current = 12 Amps. I would like to read the voltage change trhough that load, by connecting it directly to one of the analogue input channels of the DAQ 6025E. Is it safe for the card? The voltage level at that point of the circuit from where I'm reading my voltage values is about 30...40 Volts.

thank you!

Kostya.

[Jennifer O]

Hello Kostya,

Connecting 30-40 volts to your PCI-6025E would not be recommended.  The PCI-6025E has a maximum working voltage of 11V according to the specifications.   This means that the common mode voltage+signal should not exceed 11 V on any terminal.  For this measurement you will need a card with a maximum working voltage which meets the requirement of your signal or external connections to bring the signal within the working voltage of the card.

Two possible solutions include using another DAQ board which has isolation such as the PCI-6230 or using signal conditioning such as an SC-2345 and SCC-AI01.

Please refer to High-Voltage Measurements and Isolation - General Analog Concepts for information about isolation and working voltages.

Hopefully this helps,

Jennifer O.
Applications Engineer
National Instruments

[Kostya 74]

Hi Jennifer,

thank you for your response. I have already done the neccessary signal conditioning in my el. circuit to decrease the voltage level with respect to the ground, to the less than 10 Volts value.

thanks again,

Kostya.