48 volt car elect not going to happen

No, that was January 1971, long before I hired in - After which, that same switchroom looked like a big game of 'knock over the Dominoes', West to East.

The building was fine, it was typical block wall warehouse style construction, but the equipment... The aisles on the east wall were mostly vertical - the MDF and the Power Room. The bays at the west end were at about a 45-degree angle and the switches were all sorts of messed up.

They had to rip it all out and try to salvage what they could, then they invented the first Earthquake Bracing - they put a huge "Spine" down the middle of the building north-south with 12-inch square tubing verticals and a huge span of 12" I girder at rack height as a beam. Then they welded all the top iron cross-bars to the spine.

And rather than build separate racks for all the comm cabling, they just rolled out welded concrete wire - "Git 'r Done!" First "cable grid". Only racks they put up were for power cable.

I would use a very light schmear of Dielectric Grease - the lifetime supply half-pint can I have in the garage is from Trail-Rite and made for truck taillight lamps and cord connections, but 'lamps is lamps'.

Or go to the hardware store and get some Ideal Noalox, which has dielectric grease plus the flourides added to clean up the aluminum oxides and keep them from re-forming. For stubborn cases, use a stainless steel "toothbrush".

Again, where it will get really hot from a photo flood lamp you want to be really sparing with it, and keep it off the glass lamp envelope. Besides the stink factor, you might have differential expansion and the lamp outer envelope cracks, which is not good.

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On Wed, 06 Feb 2008 08:33:53 -0800, with neither quill nor qualm, Bruce L. Bergman quickly quoth:

Interesting history lesson. Thanks.

Now that you mention it, I believe I still have a small tube of dielectric grease from my automotive days. It was used between the mica insulators and the control modules in the early electronic ignition setups. If not, I may have some of the silicone grease used on spark plug wires.

Yes,I'm careful about keeping all bulbs, including cold ones, free from grease. Halogens explode nicely from a single fingerprint.

Thanks for the tips, Bruce.

-- Our greatest glory is not in never falling, but in getting up every time we do. -- Confucius

An under the right conditions so can 5V. IT is not an "inevitable" result, just a possible one. Just as working around equipment that can generate highly explosive gasoline vapors, does not mean inevitable explosions.

jk

BTW, I just now

I doubt it. I think the reason is multiple markets with different outlets jk

And that would largely be a non issue if the frame wasn't used as a conductor.

Ohh but that would cost money jk

On Wed, 06 Feb 2008 21:32:57 -0800, with neither quill nor qualm, jk quickly quoth:

Doctors kill 900,000+ people a year in the USA. Simply driving cars kills 43k in the US, 1 million worldwide. Eating fast food/heart disease kills 600k. Ask Vaughn "Which is the greater threat, us or the voltage in vehicles?" To the rest of us, it' s a moot point.

Cites:

-- Our greatest glory is not in never falling, but in getting up every time we do. -- Confucius

Perhaps part of the reason, but the main reason was to act as an interlock to keep customer's fingers out of the high voltage. (Liability lawsuits are not a new idea) The cords were usually riveted to the back cover so that you had to unplug the cord from the back of the set before you could gain entrance to the circuitry. That is why a loose cord (not riveted to a back cover) was called a "cheater" cord; because using one made make it possible to operate the set without the back cover in place.

Vaughn

He was talking about using a "cheater cord" which is what you use when servicing a TV set with the back off and the chassis out so you can take measurements while it is powered. The standard power cord is riveted to the back cover so when you remove the back cover, the power goes away (unless you have a cheater cord). :-) This was at least true of TV sets made in the 1950, 1960s, and perhaps 1970s, if not true of modern sets. (I haven't been inside one for decades, so I don't know what today's sets are like.)

Enjoy, DoN.

Please show me a documented example.

Yes it is. Thousands of sweaty mechanics working on thousands of cars. If it CAN happen, it WILL.

Vaughn

And every one of those threats is beside the point of what we are talking about.

We are talking about adding a new occupational hazard for mechanics (and firefighters etc.) If the hazard exists, the eventual results are just a matter of statistics. Given sufficient opportunity, injuries/deaths from any new hazard will eventually happen, we just don't know how often.

Then why did you even bother responding? It sure won't be a "moot point" to mechanics!

Regards Vaughn

Not to hijack the thread , but this is related. Is there any movement to LED headlights? If so/not, why/why not.

Seems to me that the light would be better and made to be easier on the eyes and reliability would be better.

Bob

OK Larry, I read your ideas carefully for the second time. Speaking as respectfully as possible, they are still beside the point. I fly, which means that I take chances that I don't really have to take. That hobby has nothing to do with the on-the-job safety of the guy who works on my car.

Vaughn

On Fri, 08 Feb 2008 21:33:58 GMT, with neither quill nor qualm, "Vaughn Simon" quickly quoth:

We're polarized on that one, so I guess we'll have to agree to disagree.

Statistically, flying is MUCH safer than driving. Are you afraid of a skyjacking or exploding plane, perchance?!?

In summary, perhaps it would be better if we just let the guy who works on our cars decide for themselves what is and isn't dangerous, eh? Our country is turning into a nanny state enough as it is. Shakespeare was right in Henry VI when he said "The first thing we do, let's kill all the lawyers." But I digress.

Ciao!

-- Our greatest glory is not in never falling, but in getting up every time we do. -- Confucius

Not when you are flying yourself in a light plane. The statistics for auto travel are better than those for general aviation by a considerable margin. Besides, my flying is not really "travel", but just recreation, so comparing to auto travel is not really relevant. I would be much safer sitting in my living room.

But in the case of the 48-volt electrical, they won't be part of the decision making process. If they want to continue feeding their families, they will accept whatever vehicle they are given to work on, and accept whatever hazards are involved.

Protecting workers is a special case. Even though we have a free market system for labor, the average middle-class worker does not always get to choose where to work, or what to work on. The economic realities of everyday life often make these little decisions for us.

OK, I have a special perspective on worker safety and let me tell you why. My wife used to work in a dental lab. (Think of a miniature foundry/machine shop) While she was working there, they changed the composition of some of the metal they were working with, but did not consider the workers important enough to even bother informing them, let alone take any steps to assure their safety. Today, my wife's lungs are ruined, functioning at only a fraction of their normal capacity because they are forever scarred from beryllium disease.

Someone knew the dangers of beryllium (it has been well documented for ages) , but thought that losing the occasional lab worker was not important compared to the profits from using a cheaper metal. Statisticly speaking, perhaps they are right. But it sure doesn't seem that way when it hits in your own home.

Once a year, we travel to a special beryllium disease clinic so my wife's condition can be monitored. She is bad enough, but not nearly as bad as some of the other cases I see. Imagine a whole line of mostly ex-metalworkers, most of them on oxygen. None of them will ever be cured. Every one of them just a statistic. Just a statistic that is, until you meet them up close & personal.

I hope it never happens you you Larry, or to anyone close to you.

Worker safety matters.

Vaughn

On Sat, 09 Feb 2008 02:59:02 GMT, with neither quill nor qualm, "Vaughn Simon" quickly quoth:

OK, so your risks are a lot higher than commercial aircraft. But it's so much more FUN in a small plane! I miss it. Dad and I used to go up, and he let me take off and fly after I passed the Basic Aviation class in high school.

Hayseuss Crisco, Vaughn. They have also had to face the risks of compressed air, revolving fans, sharp sheetmetal edges, moving fan belts, hoods dropping, doors slamming, lifts falling, greasy floors, gas fumes, gas explosions, oil toxicity on body parts, fabric offgassing of formaldehyde, benzene exposure, chlorofluorocarbons, etc. If any of them had -your- eccentric fears, nobody would be left working as a wrench nowadays.

Overprotection. What's the end result of seven to ten warning stickers on any given piece of machinery, or on the sides of cig packages? Everyone ignores them. Damned lawyers and lawsuits. My new truck has warning stickers all over the freakin' sun visors. I'll be steaming them off shortly.

Drat, that's a real bummer. But, it went with the times. Everyone smoked back then, too, even doctors. Did you find out whether or not the lab was operating according to industrial standards back then?

In the '70s, I worked doing brake jobs (real asbestos) or covered in grease/oil or around smoking tailpipes (without gloves or breathing apparati) as a mechanic for 15+ years. We were warned about breathing the brake dust and we tried not to. 'Nuff said. I know the owners of Vista Brake and I don't recall any of them having had any lung problems. They worked around it their entire lives, and father Bill smoked. One of the sons went to UTI with me.

I'm starting to get barnacles from the amount of sun I absorbed as a kid and younger adult. We weren't warned very hard back then.

Yeah, that's major suckage, to be sure. But the change in voltage isn't as high a risk as inhaling metallic dusts. It's something to be careful about.

Because you're so close to one, I believe you're overreacting.

Thanks. So do I.

Indeed it does, but nannying doesn't.

-- Our greatest glory is not in never falling, but in getting up every time we do. -- Confucius

The lumen density and focus-ability isn't there for LED headlights - at least yet, IMHO. You would need a whole panel full of 3W Luxeon style LEDs being driven rather hard - which lowers their expected lifespan. And rather sophisticated optics to deal with making a directed beam with a hard vertical cut-off (for the low beams) out of multiple point sources in close proximity - a compound lens like a fly eye. And then you have to deal with all the heat off the LEDs, a big fan forced heat sink - let the LEDs overheat and they die fast.

A metal halide or xenon short arc style discharge lamp system makes a lot more sense for the near term. They make a lot of heat but are not nearly as temperature-sensitive to their environment, so you can operate the headlights during the day in a hot climate without cooking themselves to death. They are quite energy input to lumens output efficient. The optics are a lot easier with only one point source to focus and distribute - and modify with a shutter or lens focal change for the High Beam/Low Beam pattern transition.

They make LED backup lamps, but IMHO they are more for looks and legal requirements than useful light output - takes four to replace two 1156 incandescents.

Same problem applies, they could stuff two of them full of 3W Luxeon's, and they wouldn't have to worry about optics for flood lighting - but then you would have to put a huge heat sink on the back and have free air flow or a fan cooling system. They could not be used as a drop-in replacement for a standard 4" grommet-mount truck lamp where the backside of the lamp is usually a small sealed cavity.

You can't sell backup lights or headlights with a duty-cycle time limit on them. Unless you put hard thermal cut-offs on them, so they shut down when overheated - and that would never pass the FMVSS inspection process...

Well, you could, but you'll get a lot of warranty returns from people who didn't bother to read the instructions about duty-cycle limits, and either left the vehicle parked in Reverse so they could hitch up a trailer, or installed them as Work Lights and deliberately left them running to destruction.

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Yes, but it's in the "concept car" stage at this point. I don't recall who, Porsche or Audi perhaps.

It will happen sooner than later. LED technology is advancing much more rapidly than any other illumination technology.

Viable designs have been demonstrated, the performance is there. The issue is already one of cost vs peformance, and that'll develop as the technology matures.

Oh...like Electricians?

Gunner

Yes. One maker has announced intro with 2009 models. Caddy, I think.

Problem is getting enough lumens on the road. IIRC they were using several modules (maybe 5?) for "low" beam, but only two modules for high. (that was per side) We'll see...

sdb