Alternative to a DC current transducer with 4-20 mA out

Thread Starter

Daigle72

Joined Oct 6, 2021
1
Hello,

I am wondering if this is a bad idea or a suitable solution for creating a 4-20 mA analog signal from a current shunt. Basically, I am having a hard time sourcing a DC current transducer that meets the project parameters. Will this work or fry my controller? Thanks

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DickCappels

Joined Aug 21, 2008
7,981
I vote for "fry". Ha ha ... just kidding, provided that the GND connection is actually ground and not flopping all over the place with respect to the controller's ground.

If the input to your controller is about zero ohms, this will get you a 4-20 ma signal for it. Any input resistance greater than zero will introduce and error.
 

Reloadron

Joined Jan 15, 2015
6,214
Basically, I am having a hard time sourcing a DC current transducer that meets the project parameters.
Depends on your project parameters but I used plenty of both DC and AC current transducers from CR Magnetics. Other companies make the same or similar including inexpensive versions off the boat from China. Here is an example of a CR5220 DC Hall Effect Current Transducer - 4-20 mA DC output from CR Magnetics. Using a shunt as you pictured I have used plenty of shunt amplifiers designed specifically for use with DC and AC shunt applications. Inor signal conditioners come to mind as well as others. Sounds like all you are looking for is a signal conditioned to take a signal off a shunt (0 to 50 mV) and give you a signal you want (4 - 20 mA) which you can scale for your application. Any of these solutions off the shelf turn key will avoid problems like Dick mentions above.

Ron
 
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