Appeal No. 1997-2216
Application No. 08/392,661
of reclosures is to be limited because reclosures are only
useful in situations where an overcurrent has occurred for a
brief period. Therefore, it would have been obvious to the
skilled artisan to limit the number of pulses using a counter
in Sears' overcurrent protection arrangement, since the pulses
are only effective for a transient overcurrent, and thus for a
brief period of time. Consequently, claims 1 and 12 would
have been obvious over Sears in view of Zocholl.
As to claims 2, 3, and 8, Sears illustrates in the figure
and describes in column 3, lines 38-51, a pass transistor 13
and driver transistor 15 in a Darlington configuration, series
connected in the line of the circuit, which act as a switching
transistor, and a latching transistor 17 that determines the
base current to the switching transistor and acts as a control
transistor. As shown in the figure, the base voltage of
transistors 13 and 14, the switching transistor, is determined
by a voltage drop across the switching transistor. Further,
regarding claim 4, latching transistor 17, the control
transistor, is coupled to a voltage divider formed by resistor
18 in series with resistor 19 (column 3, lines 52-54). The
pulses from the pulse generator supply the base voltage to a
8
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 Next
Last modified: November 3, 2007