Posted on 02/21/2008 7:27:30 AM PST by george76
What a nightmare! Reminds me of Paul Shanklin’s song “in a Yugo”.
Great, the libs can drive around feeling good about themselves and then get electrocuted in a minor fender bender. But the rescue worker should not be forced to risk life and limb for a routine extraction.
Let’s not mention the disposal of cells (kind of like CFL’s). Or ethanol?!?!
When will the madness end?
” But Al Gore says we should count all the volts. “
Dolts. Count all the Dolts.
Are the Tahoes flex fuel or true hybrid?
We looked at a few and Suburbans— just bought a new vehicle. We went with GM, but it was an Escalade.
Well, they do reduce emissions in city driving, where they can stop with no idling, and run short distances off batteries alone, along with the regenerative braking. A pure electric would make a lot more sense for that purpose. Much of the benefits of hybrids in the city could be achieved in regular cars by also having them stop their engines when stopped, and restart them when they need to move, just like most any golf cart can do.
It’s spelled P-r-i-e-s, but pronunced “Pious”.
Car batteries are designed to throw a lot of amps, for seconds at a time, to start your car. Linking enough together to get 300 Volts will kill.
I gotta pay the guy who mow’s my lawn more than that - $25/hr now.
The Volkswagen TDI is a low emission vehicle, and gets approximately 1.5 times the mileage of the hybrids, with better acceleration. I've got a Chevy HHR with a gas engine that gets a legit 25 combined, so the hybrids are delivering not that much more mileage for significantly higher complexity, and the "green" aspect is totally wiped out when you consider the cost of recycling/replacing batteries.
There's a better solution, but the current hybrids, IMHO, aren't it.
“But you also need enough voltage to push that amperage through your bodies resistance. A 12 volt lead acid battery can throw a lot of amps to start your car, but doesn’t have the oomph to push it through your body for more than a nasty jolt. “
That’s a very good point. It takes a proper combination of both.
““It only takes 50 to 100 volts to kill a person.”
The author is a scientific ignoramous. You can take a 100000 volts without a problem. It the amps that kill you.”
Not entirely true that the author is an ignoramus.
Yes, it’s the amps that kill you. Not very many of them. IIRC 0.5 of 1/1000 of an amp is enough if it is in the right place, say, through your heart. [quicky check on google says 0.7 of 1/1000].
But since E=IR [Volts=Amps X Resistance], if your body resistance is low enough, then you can multiply that 1/2 milliamp by your skin resistance to come up with a lethal voltage. Then it’s just a questin of whether the voltage source as suffient charge and low enough internal resistance to deliver the amperage long enough.
And the length of time is crucial in at least one respect — as the current continues to flow, your skin resistance drops quickly, thereby letting the current rise further.
I can’t remember the skin resistance figures, but probably the right 50V source could fry you under the right circumstances.
BTW, when you walk across a rug and touch the doorknob on a dry winter day, any shock you can feel is AT LEAST 3,500 volts. That’s what they told us at ESD prevention school. Microelectronics can be wiped out with a tiny discharge of a couple of hundred volts, and they were trying to explain that it is way below the threshold at which you would notice it.
Well, I checked my recollection that 0.5 milliamps could kill a person, and it appears I was incorrect. This source says that that is the threshold at which most people PERCEIVE the current (tingling sensation).
0.5 to 3 mA Feel the energy, tingling sensation
3 to 10 mA Experience pain, muscle contraction
10 - 40 mA Brain says let go; but physically cannot do so(Grip paralysis)
30 - 75 mA Respiratory systems shuts down
100 - 200 mA Experience heart fibrillation
200 - 500mA Heart clamps tight
Over 1,500 mA Tissue and organs burn
Is that a “positive” or “negative” thing?
Actually, when you say "440 volts AC", that is the RMS value. That power source actually reaches over 600 at peak (if it's a sine wave.) That, by the way, is enough to jump through an appreciable air gap.
A 300 volt battery is just that - 300 volts. I still wouldn't touch it. A DC shock is one solid mule kick.
Excellent point, and one that I completely forgot about. RMS voltage is .7071 of peak, so 440 x 1.414 is 622 volts peak.
And you’re right, I wouldn’t touch either one. On purpose.
No. The electric motor has to draw hundreds of amps at startup.
Do hybrids use negative ground, floating ground, or something else? Do they use the chassis to actually carry any current?
If there is no need for the chassis to actually carry current, I would think it might be safest to have the chassis driven 'weakly' to a voltage level some distance from either supply and then have a fail-safe system which would disconnect the batteries in case the chassis was shorted to either supply lead.
They advertise them as hybrids. I went with my husband to the auto show in Chicago last week. He works for GM. I will ask him. I really don’t know.
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