Miele W1113 - 060-1 Pulse Width Modulation Motor Speed Control; Function

Technical Information
39
W1113, W1119, W1203, W1213 & W1215 Clothes Washers
1 Technical Data
Main Motor: DC variable speed (see 2.1 for details on control)
2 Function
2.1 Motor Control
UB Operating voltage
UM Motor voltage
T 1 period, frequency approx. 20 kHz
ti Power on
tp Power off
t Time
Figure 060-1: Pulse width modulation motor speed control
A bridge rectifier circuit on the power electronic provides the DC
voltage supply for the motor. Pulse Width Modulation (PWM)
circuitry controls the DC voltage by varying the duration of power
(on / off in pulses) provided to the motor.
The proportion of ti (DC pulse on) and tp (DC pulse off) controls
the motor speed. A tachogenerator (on the motor) monitors the
speed of the motor.