Abstract
The control phase of a 2-phase servomotor is often driven by an amplifier containing a DC component in the output.
In this case, a torque alternating with the source frequency is produced and causes undesirable problems.
In this paper, an equation is derived to calculate the alternating torque by using the equivalent circuit parameters.
Experimental results with the sampled 2-phase servo motors are in good agreement with the calculation by using the above equation.
The alternating torque characteristics of a 2-phase servomotor operating under the condition of containing DC component are calculated.
These calculated results are compared with those of the case in which the torque alternates with double the source frequency due to the unbalanced mmf.
