the aligned axis, of the phase current waveforms during
motoring action results in a lower chopping frequency and
lower switching losses than the conventional current
regulation schemes.
Stephens teaches in column 5, lines 45-50, that Figure 4
illustrates a preferred embodiment of the control circuitry of
the current regulation means. Stephens teaches in column 5,
line 51, through column 6, line 26, that the control circuitry
of the current regulation means receives a signal proportional
to the sensed phase current, Isense, a commanded reference
current waveform, Iref, and a logic signal, INTERVAL signal.
Stephens discloses in column 6, lines 27-66, that the INTERVAL
signal
determines the turn-on and turn-off angle. Stephens is silent
as to how the interval is determined.
Returning to Figure 1, Stephens shows that the machine
control means 50 provides the drive signal that determines the
turn-on and turn-off angle. As pointed out above, Stephens
discloses that the machine control means 50 is disclosed by
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Last modified: November 3, 2007