From: Terry Pinnell
Subject: Re: Flash a string of LEDs
Date: Thu, 05 Dec 2002 08:01:34 +0000
NNTP-Posting-Date: Thu, 5 Dec 2002 08:01:55 +0000 (UTC)
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"fred bartoli" wrote:
>Terry Pinnell a écrit dans le message :
>> It's a Spice issue, as it worked fine on breadboard with component
>> values as per your/my circuit schematic (about 1 Hz).
>> If Helmut Sennewald or Fred Bartoli see this and have the time and
>> inclination, it would be educational to see how they get it simulating
>> in SWCAD III and ICAP respectively. Probably too much to hope for
>> anyone else with CircuitMaker.
>> I scattered .IC parts around liberally, rang the changes on step
>> times, and even kicked my desk, but still no regular output.
>the circuit works nice... once you have settled the UIC (use initial
>conditions) flag on the .TRAN line and given an initial condition of 0V for
>the 22uF capacitor.
>Otherwise the circuit have (with the original values) a stable state that is
>found at the initial bias point calculation. Common startup problem of
>oscillators with spice.
Thanks Fred. I had another try with UIC enabled, as well as IC=0 at
the top of the 220uF cap. (BTW, I note you said '22uF'. Are you using
the identical circuit to me, as posted at
But still couldn't get it working. What step and stop time did you
Hobbyist, West Sussex, UK