Alt-BEAM Archive
Message #07671
To: beam@sgiblab.sgi.com
From: "Jim Cook" beamboter@hotmail.com
Date: Sun, 14 Nov 1999 12:53:54 PST
Subject: [alt-beam] Re: Hackable?
>Jim, I have these and find the gearbox is very crude ... and poor quality
>throughout...
>but feel free to try if you are only seeking a shape???
>Timothy...
Really? I thought I found the answer to the Line bot idea that was passed
around last week.
______________________________________________________
7672 Sun, 14 Nov 1999 14:04:29 -0800 [alt-beam] SUCCESS?? (Sort-Of) Solar H Project "'beam@sgiblab.sgi.com'" Wilf Rigter > Yes, you are right!
>
> All Gold caps are not created equal. With the exception of the P6969-ND,
> the NF Series are NFG (not suitable) for "high" discharge current required
> for motors because they have high internal resistance (Rint), ranging from
> 30-150 ohms with the 6951-ND rated 0.047F at 5.5V with Rint=120 ohms!!!
> The AL Series is the best with the smallest rated 0.33F at 2.5V with
> Rint=1.7 ohms and the largest rated 10F with Rint=0.1ohm. For higher
> voltage (ie 5-6V) applications, use two AL units in series providing
> roughly half the rated capacitance at double the rated voltage.
>
> You may also want to check out what is probably the cheapest source of AL
> caps : The Mattel XV racer @ cdn$7
>
> The interesting thing about these caps is that they seem to be quite
> robust, able to withstand being overcharged (but watch out for
> overheating!) without damage. For example the Mattel XV racer uses a
> 4.7F/2.5V rated AL cap which is charged from 4.5V battery which
> overcharges the cap to about 3.0-3.5V while the leakage current through
> the cap increases to several 100 ma! A good way to heat up the cap and
> empty the battery I would say. When removed from the charger, even without
> a load, the cap continues to discharge excess voltage and settles down to
> about 2.8V after a few seconds.
>
> Very interesting technology!
>
> Wilf Rigter mailto:wilf.rigter@powertech.bc.ca
> tel: (604)590-7493
> fax: (604)590-3411
>
> -----Original Message-----
> From: SG [SMTP:Sparkyg@seark.net]
> Sent: Sunday, November 14, 1999 8:08 PM
> To: Wilf.Rigter@powertech.bc.ca
> Subject: SUCCESS?? (Sort-Of) Solar H Project
>
> At 06:17 PM 11/13/99 -0800, you wrote:
> >I'll look at this and reply tomorrow if no one else has answered by then.
> >
>
> Hi Wilf!
> i'm begining to suspect my storage cap. maybe i'm using the wrong type?
> it's a 47f gold cap part # P6951-ND .
>
> the reason why i suspect it is, my 4700uf cap (solarbotics) seems to power
> the pagr motor even longer than the 47f does. (not by much maybe a
> fraction
> longer)
>
> so, im sending you a graphic file captured from the pdf digikey catalog
> that listed the cap in question. (hope its not too big.)
> i thought there might be some relavant info there if i have the wrong
> component!
> regards!
> -Sparkaholic << File: capinfo.jpg >>
7673 Sun, 14 Nov 1999 17:16:03 PST [alt-beam] Re: Hackable? beam@sgiblab.sgi.com "Timothy Flytcher" >>Jim, I have these and find the gearbox is very crude ... and poor quality
>>throughout...
>>but feel free to try if you are only seeking a shape???
>>Timothy...
>
>
>Really? I thought I found the answer to the Line bot idea that was passed
>around last week.
I think it would be much easier to start from scratch... as there is nothing
I can salvage from them but the general Idea, and you can get all that just
from the box...
______________________________________________________
7674 Mon, 15 Nov 1999 02:07:41 GMT [alt-beam] BICORE POWER beam@sgiblab.sgi.com "Mike Kulesza" Is it safe to use 9V on the "complete walker"? - it has a 240 and 2
h-bridges...
______________________________________________________
7675 Mon, 15 Nov 1999 13:48:17 +1100 [alt-beam] Re: Elmos web site is online...REVIEW beam@sgiblab.sgi.com Elmo
Greg Powell wrote:
> a link isn't a link if it isn't a link :)
Wow...thats deep and philosophical......
I LINK......THEREFORE I AM!
Elmo
Home