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Lorenfb Lorenfb is offline
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Join Date: May 2003
Location: Manhattan Beach, CA
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Q1 forms a voltage regulator. Q2 & Q3 form a one-shot with .47 & 2K
basically providing the timing ~ 1ms. Each ignition trigger "fires" the one-shot
which provides an average current to the meter proportional to the RPMs.
Note: Q2 is biased "on" and an input of 90-100 volt positive pulse is required
to turn "off" Q2 and trigger the one-shot.
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'88 911 3.2
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Last edited by Lorenfb; 11-23-2007 at 05:29 AM..
Old 11-22-2007, 12:41 PM
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