Appeal No. 2000-1938
Application 08/940,467
breakover current will be undesirably high, whereas
with the capacitor, the rate the voltage and current
discharge from the high side to the low side can be
made more gradual.
Answer at 4. Fritschi does not contain such a teaching.
Instead, Fritschi explains the function of capacitor 19 as
follows: "The gate-source capacitor 19 with a time constant of Te
is charged through the start-up load resistor 16. After at least
one time constant the MOS-FET 11 is named [sic, turned?] on and
switched to low resistivity." Column 4, lines 36-40. Subsequent
conduction of NPN transistor 21 "discharges the gate-source
capacitor 19, whereupon the MOS-FET 11 becomes highly resistive."
Column 4, lines 61-65. Furthermore, under the circumstances
described at column 5, lines 15-22, the gate-source capacitor 19
will be partially discharged as a result of leakage currents
through Zener diode 20, NPN transistor 21, and MOS-FET 11
(col. 5, 11. 23-25).
In response to Appellants' criticism of Fritschi as not
teaching that capacitor 19 rounds the kink point of a zener diode
(Brief at 11), the examiner contends that
[t]his argument is not persuasive because, as appellant
is well aware, it is not necessary that the purpose of
a claimed invention be the same as that of the prior
art, and all that is necessary is some motivation for
combining the teachings of the prior art so as to
achieve the claimed invention, and such motivation can
be the same as or different from that of the applicant.
Answer at 5. While this is a correct statement of the law, In re
Beattie, 974 F.2d 1309, 1312, 24 USPQ2d 1040, 1042 (Fed. Cir.
1992), the examiner has not explained, and it is not apparent to
us, what different motivation an artisan would have seen in
Fritschi for adding a capacitor in parallel with one or each of
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