We are using a stepper motor with a Current rating of 0.65A and rated voltage of 4.55V. We are using a 12v power supply. The current driver chip is limited to supply 0.7A.
Would the power of the motor be equal to Supply Voltage * Rated Current. Or will it be equal to motor rated voltage * rated Current.
The power absorbed by stepper motors varies depending on the state of the motor and driver.
When holding position using full step or half step, the power will be governed by:
\$P = I^2R * Coils\$
where
If you are holding a micro-stepped position then it gets more complicated since you need to calculate the impedance of the coils at the PWM frequencies and do the appropriate math for whatever coils are on and off with the duty cycle involved.
Similarly, while being driven at some speed, the impedance of the coils at the applied step rate also needs to be calculated.
At higher speeds where the step time is less than the time constant of the coils the calculation gets more complicated and the power absorbed actually drops off markedly as it becomes harder and harder to establish the drive current.
You can calculate the electrical power dissipated by the motor as motor volts times motor amps.
The mechanical output power of the motor will not be more than a tiny fraction of that, stepper motors are not designed to be efficient.
Current of Font = ((Vmotor / Vfont) * (Itotal) * Ms
Itotal = I (motor) * number of motor coils (usually 2) Ms = margin of safety (can be set 2)
If you power the driver PWM with 12v
((4.55/12) * 1.3) * 2 = 0.98A
Its 12-volt supply should provide 0.98A for each motor
If you use 3 step motors: 0.98 x 3 = 2.94
Its electrical source should be 12v x 3A
<sub>...</sub> for subscript. What is "Font" in your first line? Add in the missing punctuation while you're at it. It's important and leaving it out makes your post look a lot less credible. 'V' for volt and there's a space between the numbers and symbols according to the SI standard, if you care.
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Commented
Oct 1, 2018 at 19:50