Appeal No. 97-1320
Application 08/431,001
DECISION ON APPEAL
This is a decision on appeal under 35 U.S.C. § 134 from
the final rejection of claims 1-5.
We reverse.
BACKGROUND
The disclosed invention is directed to a waveshaping
predriver for controlling the application of pulsed current to
an inductive load via a voltage controlled power transistor,
characterized in that the turn-on and turn-off slew rates of
the pulsed current are substantially equal.
Claim 1 is reproduced below.
1. A waveshaping predriver for a voltage controlled
power transistor for producing output pulses in response
to input pulses applied to said predriver, said predriver
comprising:
a constant current source which is turned on and off
by said input pulses for producing a control signal
coupled to the power transistor for turning the power
transistor on and off for each input pulse; and
a waveshaping circuit for limiting said control
signal to a predetermined rate of change at turn-on and
turn-off including a resistor and capacitor combination
coupled to said constant current source such that said
capacitor (1) is charged through said constant current
source at a rate determined by said resistor when said
current source is turned on to establish a desired
turn-on slew rate of said output pulses, and (2) is
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