Subject: Re: Reducing contact resistance for low volt use?
Summary: What do you think of these ping times eh?
Reply-To: You can't see me, and I pass right through planets...
References: <firstname.lastname@example.org> <email@example.com> <firstname.lastname@example.org> <email@example.com>
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Date: Tue, 07 Jan 2003 11:52:27 GMT
NNTP-Posting-Date: Tue, 07 Jan 2003 06:52:27 EST
On Tue, 07 Jan 2003 05:40:49 GMT, jmuchow@SPAMMENOTcamlight.com (John
Muchow) Gave us:
>We're building a constant-current discharger. We don't want to hold
>the voltage anywhere. We don't want additional current ready to be
>switched in. This isn't for our 'bots or other folks planes/cars.
I was referring to the real application device, yes, not the tester.
>Or are you talking about powering our 'bots?
>If so, we don't care if the voltage drops during use. Most of these
>combat robots are designed to never reach that point in the battery's
>life (past the level "plateau" of a typical NiCd discharge curve).
But the lightweight caps could kick in that little Ummmph that is
need, right at that critical, battery popping moment.
>And the extra weight of those capacitors won't help us (they're big
They are light and nowhere near as dense as batteries of any kind
are. What they are is high rate of discharge devices that could save
your but in the clutch . :-]
> If we take the current from the batteries, or the capacitors
>after coming from the batteries, it's all the same. And the
>inefficiencies resulting from another step (storing in caps or DC-DC
>converting) definitely won't help us.
You underestimate the ability of a DC to DC converter to respond to
transient demand cycles. You should look at that.
As far as the caps go, they can be pre-charged and used to dump a
wad of juice in at a critical moment. Kind of like a defibrillator
that is strapped on at the start, but only gets used in an emergency
pulse need or shutdown/stall situation.
>And those caps would be juicy pickings for another bot's weapons. The
>DC-DC converter would just be another layer of delicate complexity
>that might fail with the huge G-loads these bots experience...even if
>the other bot doesn't shred it.
You need aluminum panels on that thing. They stop grenades and
bullets regularly if you get the right stuff. A cubic yard boxed up
in it probably wouldn't weigh more than 30 pounds. I'm sure you have
a lot less surface area than that to protect.
>This sport is a lot more evolved than you're imagining. Lots of VERY
>talented folks from different engineering fields builds these things.
Have they ever worked on armored limos?
>And they have put years of work into them.
Sounds like the new millennia's replacement *thing* to spend all
that extra money on. A very expensive hobby.
Better than the sixties and seventies tho. Weed, Lsd, and then coke
sucked a lot of you rich boys' cash away back then. Nowadays, they
buy XTC at $40 a pop. There are suckers born every minute.
>>>> Hey! I know! Lets just put a big coil of wire in the car, and
>>>>excite it inductively! Hahahaha.... Like a door pass key.
>>>> Yeah... we could send a whole 500 femtowatts to the car! :-]
>Well, there is an "Ant" class. They use a bit more power than that,
>but not by much.
Heheheh... I like it. Robo-roach.
250 pounds eh?... Hmmm...
I used to make a hypo-hyperthermia machine that had a stainless
steel sheet based, hand made "angle iron" framed (from the stainless)
frame that was pretty lightweight, but strong. It had a powder coated
sheet steel "skin" around that. Find three of those, and link them
It was about slightly less than two feet in diameter, just over
three feet tall, had 2.5 inch wheels, and held an air conditioning
compressor, and heating unit in it for a water bath it also held. It
was for taking patients down to near freezing, so that open heart
surgeries could last longer, blood flow rates be reduced, oxygen need
be reduced, and mortality rates decline. There is one in every
hospital in the world practically.
That frame was bolted together with "six stroke" "grade six?" bolts
that were so lame, they twisted like taffy. Grade six? Yeah right.
Anyway, box that sucker up good in aluminum panels of the right
grade aluminum, and make it impervious to all but DU rounds. hehe