Is 'ke' (coefficient of BEMF) of a stepper motor specified in Vpp, Vp or Vrms?

[MBaum.7]

According to AN4144, page 14/28, the coefficient 'ke' is measured by turning the stepper and measure the phase voltage with a oscilloscope. For the coefficient 'ke' in V/Hz, which voltage normation should be used:

• Peak-to Peak, Peak or RMS?.

[Cristiana SCARAMEL]

Hello @MBaum.2gartner​,

with reference to the AN4144 section 2.1, at page 14 it is suggested a method to measure the Ke parameter. The description of the method shall refer to peak voltage.

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[MBaum.7]

Hello Cristina

To clarify - do you mean the Peak to Peak voltage or the voltage from Ground to Peak (half of Peak to Peak). Or to refer to the measured signal in the oscilloscope screen: 1.74 V or 3.48 V?

[Cristiana SCARAMEL]

Hello @MBaum.2gartner​,

I mean peak voltage so in your waveform 1.74 V ;)