Doc got POWER!!!

Batteries, Chargers, and Battery Management Systems.
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amberwolf   100 GW

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Re: Doc got POWER!!!

Post by amberwolf » Jul 03 2010 8:01pm

texaspyro wrote:
fire pillar.jpg
And indeed, that's me... and no photoshopping was involved.
I guess I wasn't too far off. :lol:

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dequinox   10 kW

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Re: Doc got POWER!!!

Post by dequinox » Jul 03 2010 9:49pm

GOOD GOD! Was that really shorting out batteries or what??? :shock: :shock:
The current political climate is akin to the discovery of anti-gravity for swine.

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texaspyro   100 kW

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Re: Doc got POWER!!!

Post by texaspyro » Jul 03 2010 11:14pm

dequinox wrote:GOOD GOD! Was that really shorting out batteries or what??? :shock: :shock:
Well, in a way... Take 14.4V of NiMH battery, apply via a rather sophisto failsafe wireless relay link (designed and built by yours truly) to a 5 mil tungsten wire coated in a magnesium-teflon-nitrocellulose mixture inserted into an ammonium perchlorate/hydroxy terminated polyurethane rubber mixture doped with titanium flakes, catalyzed by yellow iron oxide, contained in an 6061-T6 aluminum alloy tube with a graphite orifice (aka a "K" class sparky rocket motor), stuck in a rather nifty high-power model rocket, press button, voila...

More such tomfoolery at: http://tjm.home.texas.net/asa102707/asa102707.html

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dequinox   10 kW

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Re: Doc got POWER!!!

Post by dequinox » Jul 04 2010 1:01am

You could've just said, "No it's a model rocket." :?

Lol :lol:
The current political climate is akin to the discovery of anti-gravity for swine.

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CamLight   10 kW

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Re: Doc got POWER!!!

Post by CamLight » Jul 04 2010 1:24am

voicecoils wrote:I've often been surprised about the excitement surrounding ultracaps/supercaps for exactly that reason. For most EV applications, power density has not been holding back EVs with lithium batteries. Energy density is where the gulf between secondary battery tech and liquid fuels is still massive.
Agreed.
But ultracaps used as a provider of short burst of current not only save wear and tear on the cells, but can do some pretty remarkable stuff. What I can do with just a few A123's and some relatively small ultracaps amazes me (compared to what I need if using cells only). But, outside of these types of applications, there are certainly other options that can be better choices than these caps.

But, for guessing Doc's secret weapon, my vote is still ultracaps. :)

texaspyro   100 kW

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Re: Doc got POWER!!!

Post by texaspyro » Jul 04 2010 11:15am

dequinox wrote:You could've just said, "No it's a model rocket." :?
Aww, now where's the fun in that... :wink:


Actually, lighting some of the large model rockets can be quite a challenge. Doing it safely even more so. The igniters may draw over 20 amps each. They are usually just a small coil of resistance wire dipped in a pyrogen.

A clustered rocket can have several motors (I know of one with over 40). You need to light them all within a few milliseconds. A firing system that supplies too much power can burn out an igniter before it has a chance to light the propellent. I am going to try one of those ultracaps in one of my firing systems...

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AussieJester   100 GW

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Re: Doc got POWER!!!

Post by AussieJester » Jul 04 2010 7:44pm

Have you seen the water rockets texaspyro not talking the pop bottle jobs
talking about the 8 foot jobs that get up to few thousand feet on air
pressure alone, i always wanted to make one but haven't been able to source the fluorescent light
protective tubing the guys use to build them.

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texaspyro   100 kW

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Re: Doc got POWER!!!

Post by texaspyro » Jul 04 2010 8:08pm

AussieJester wrote:Have you seen the water rockets texaspyro not talking the pop bottle jobs
If I remember my math correctly (it's been a while since I flew a douche bag rocket) the Isp (specific impulse) of a water rocket is around PSI/16. If you can maintain a pressure of around 3500 PSI, you can exceed the performance of the propellent in the space shuttle solid rocket boosters.

A friend of mine has access to some 4 foot diameter fiberglass tubes with a wall thickness of around an inch. We were going to try and get Red Bull to sponsor us in a flight filled with Red Bull at a few thousand PSI. :twisted: Unfortunately, life got in the way... :(

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