Appeal No. 1998-0507
Application No. 08/457,701
of the drive circuit for a brushless motor across the DC bus lines in order to power the Hall
effect device.
Appellants point out that Gerfast is the only reference that shows a current limiting
capacitor and it has no speed control, contrasting this with Morinaga and Müller
which provide speed control. According to appellants, since Gerfast provides a current
limiting capacitor in order to provide current control while Morinaga and Müller have a
commutating control circuit which provides speed in lieu of current control, it would not
have been obvious to combine these references to include the current limiting capacitor of
Gerfast in the Morinaga and Müller devices. Appellants point out that the instant claimed
invention employs both speed control and a current limiting capacitor in a polyphase
commutated brushless dc motor. Since the references relate to different types of motors, it
is appellants’ contention that they are not combinable.
We disagree. Appellants do not dispute that Morinaga and Müller relate to
polyphase commutated brushless dc motors similar to appellants. Applying Morinaga to
independent claim 80, for example, since appellants do not argue the specific limitations
of any one claim over the others, Morinaga discloses the operation of a dc motor
energized from an ac source through a rectifier 2 having an output side providing a dc bus
voltage. The output of the ac source is rectified. A motor 5 is connected
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