Alt-BEAM Archive
Message #03181
To: sbolt@xs4all.nl; beam@corp.sgi.com
From: Bumper314@aol.com
Date: Tue, 11 May 1999 00:17:15 -0700
Subject: Re: SMD SE
> In a message dated 5/10/99 11:18:35 PM Pacific Daylight Time,
sbolt@xs4all.nl
> writes:
>
> >If you trigger at for instance 2.5V, and your driver is any good,
> >you'll be wasting an initial 150mA through that resistor!
>
> I thought the pulse looked a little dead =), so what should i do then. I
cant
> swap out the SE now, its in the middles, I can get to it though. Should I
put
> a resistor in series with the solar cell?
>
>
> > SunEater_V fits easily on 2.7x3.5cm. Very enthousiastic,
> > tinyPager-motored `bot.
> > But if you have easy access to a nice choice of 1381s, why not use
> > them. 1381 output connects to the active high input of a monostable
> > (1/2 74HC221, for instance). A 100N cap and a resistor - somewhat
> > less than 1M for best pulse, I imagine - determine the output
> > timing. 1K connects a BC817-25 to the active high output. The
> > transistor drives your coil and there you probably are. The
> > smallest supercap (47000uF) would provide sufficient current in a
> > light and compact package, and the voltage would hardly drop
> > between pulses.
> >
> > That's five and a half components for a single SE, or eleven for a
> > double version. The 74HC221, all resistors, the 100N cap and the
> > driver are SMT. Your 1381 will seem rather large...
> >
>
> wow, is stuff up on your SunEater_V yet? I dont think i followed your
> description to well on that SE, would you mind wipping up a schematic? And
> about my 1381, I guess I didnt write that well, I actually made another
one
> tonight and its only 5mm by 5mm by 2mm. not bad.
>
> STeve
>
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