Pulse-width modulation
(PWM), as it applies to motor control, is a way of delivering energy through a succession
of pulses rather than a continuously varying (analog) signal. By increasing or
decreasing pulse width, the controller regulates energy flow to the motor shaft.
The motor’s own inductance acts like a filter, storing energy during the “on”
cycle while releasing it at a rate corresponding to the input or reference
signal. In other words, energy flows into the load not so much the switching
frequency, but at the reference frequency. PWM is somewhat like pushing a
playground-style merry-go-round. The energy of each push is stored in the inertia
of the heavy platform, which accelerates gradually with harder, more frequent,
or longer-lasting pushes. The riders receive the kinetic energy in a very
different manner than how it’s applied.
Pulse width modulation
(PWM) is a technique of controlling the amount of power delivered to an
electronic load using an on-off digital signal. The fraction of the period for
which the signal is on is known as the duty cycle. The average DC value of the
signal can be varied by varying the duty cycle. The duty cycle can be anywhere
between 0 (signal is always off) to 1 (signal is constantly on).
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