Re: Any good ideas on this circuit problem?

From: Winfield Hill (Winfield_member_at_newsguy.com)
Date: 09/12/04 

Date: 12 Sep 2004 06:11:27 -0700

Klaus Vestergaard Kragelund wrote...
>
>> . 23v 10pF
>> . _| ,--||--, _
>> . | \ | | | \
>> . Osc | >o--+-/\/\-+--+---| >o
>> . |_/ R27 | |_/
>> . | /
>> . 8v5ref \R28
>> . /
>> . |___339output
>
> Also what I had in mind in my first troubleshooting. I was however conserned
> about the case when the 139 is active - pulling R28 down. Then I think a
> negative pulse at the osc output inverter would source a spike of current
> into the second gate perhaps leading to SCR latchup. Am I mistaken?

 The capacitor should be just large enough to cancel the gate's input
 capacitance. This will be far too small to have any bad problems. 

-- 
 Thanks,
    - Win
 (email: use hill_at_rowland-dotties-org for now)
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