Current Sensing

I need to tap into the Collective regarding current sensing ideas. I would like to monitor a DC voltage from say zero to 60 volts and a maximum current of 40 amps. I have tapped into the other Elites but now I would like to ask the Community.

Has anyone used a maxim MAX9611 High-side I2C current sensing amplifier. Or an Allegro ACS Series hall-effect current sensor. Or a TI INAxxx current sensing amplifier. I would love your ideas and stories. :grinning:


Hi @peekay123

What type of loads will you be monitoring? Resistive or Inductive? I would certainly take that into account when selecting the proper electronics.

@IOTrav, good question! The current sensor is to go between a solar/wind charger and a battery (DC).

Hi @peekay123

Sounds like there is a chance of inductance if there will be a wind turbine(DC Motor). Would be tough to see without an Oscope on the circuit. I would certainly keep that in mind during your development.

We are an electronics development company. I will run this past a couple of engineers here to see what they think. How many circuits do you need to monitor? Just one?

Hi @peekay123

This is an expensive solution but I must say I have used Veris Industries sensors in the past and I can say they are top notch.

While this sensor may be expensive you would not need to do much in the way of circuitry. The signal would just need to be conditioned a bit for the Spark’s 0-3.3VDC A/D inputs. A simple voltage divider circuit would work nicely but will need to be taken into account in your formula to determine current.

Just a thought.

@IOTrav, the output of the turbine is DC since it has its own charge controller. I am not looking for an industrial solution ($$) though that product looks great. I am starting to lean to an ACS722 but I greatly appreciate your suggestions and those of the community :smiley:

I had this one bookmarked in my ebay…

and this one


Hey @Hootie81

That current transducer you linked is cool. I wonder how accurate it is. Any idea if its 0-5VDC output is linear? Plus you can use it for AC up to 75 amps to!

No idea about the actual linearity but the info in the description suggests it’s linear. There is an equation. Current (A) = (V1 - V0) / CF the V0 and CF will be supplied with the sensor (or you can calculate yourself pretty easy)

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Wow. A sensor that has a freakin formula in the freakin datasheet? Genius! Why cant all sensor manufacturers do that :smile:

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@IOTrav, no kidding. I am looking at the Maxim MAX9611 current sense amplifier with I2C. It is really well priced and does a lot of cool stuff but try and find design and layout guidelines! Geesh :weary:

Bear in mind that the core is not the best at measuring absolute voltages via the ADC. It is best when measuring the proportion of 3V3* (which may not be 3.3V at any moment in time.)

If you don’t have a digital sensor, consider putting an i2c/spi ADC (with good reference) as part of your data acquisition circuit.

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@AndyW, good point, making me lean towards the MAX9611 since it has everything. I’ll see what I can get for an I2C ADC to use with the Allegro sensors. :smile: