steppermotor

[helm]

Hello

I am looking for the possibility to measure the current from each coil of the stepper motor

if anybody knows something about that, please can you give me an idea?  thank you helm

[dacad]

To measure current, use ohm's law.  Measure the voltage drop across a precision resistance in the circuit.  The resistance is known, the voltage will be known, solve for current. This entails adding a precision resistor in series with each coil with enough rating to handle the expected overall wattage.

[Sam_Sharp]

As dacad has mentioned you can use a low-resistance precision resistor in series and measure the voltage across it.

You can also get hall effect current sensors where you pass the coil wires through a sensor (one or more times) and it will output a voltage proportional to the current. This is a slightly less convenient solution (have to pass coil wires through sensor / they need an external supply) but it has the advantage that it has no impact on the circuit that it's measuring the current of (you will drop some voltage across the resistor if you use that method).

[apok]

dont forget to consider Power(W) in choosing your shunt R   

[dacad]

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@Sam_Sharp wrote:

You can also get hall effect current sensors where you pass the coil wires through a sensor (one or more times) and it will output a voltage proportional to the current.

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Got me wondering if a brushless motor hall effect would work for this but I'm thinking it is more of a binary component rather than an analog component.