Refected Power

So who was right, then? Westinghouse or the, er, other power co?

"Helmut Wabnig" napisal w wiadomosci news: snipped-for-privacy@4ax.com...

Look at the pictures:

Tesla was Father of the AC and Father of radio. Do not you know that? S*

mode/2up

And broke! But there's a fine line between madness and genius and I prefer to believe he was the latter.

I don't doubt Tesla's importance in Power systems, but in terms of contribution to the development of radio, I believe he scarcely merits a mention behind the likes of Marconi, Faraday, Henry, Hertz, Maxwell and Lodge!

Yes. No. Or -- there's no good answer to the question as framed.

For local to regional distribution, AC works better because one just needs to run it through a transformer to step the voltage up or down.

For a lot of other things, DC works better.

I think that history bears out Westinghouse (and Tesla), though.

--

Tim Wescott 
Wescott Design Services 
http://www.wescottdesign.com

Well, Edison was perfectly right, if you touch one of those DC things, you're toast. ;)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net

Edison was the DC guy. It was Westinghouse backing Tesla that was pushing AC.

--

Tim Wescott 
Wescott Design Services 
http://www.wescottdesign.com

Why? AC is more lethal volt for volt than DC.

Quite right. OTOH touching the AC one would be approximately as lethal.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net

I'm pretty sure that it's the same if it's peak volts to peak volts.

RMS to RMS, though, yes.

--

Tim Wescott 
Wescott Design Services 
http://www.wescottdesign.com

Nope! AC is worse on account of the average human body being - for electrical purposes - reasonably accurately represented by

100pF || 1500 Ohms (the so-called 'Human Body Model')

Some disagreed enough to have started a court case out of it.

I think we are getting to the point where DC is better period. Because now we have DC convertors so efficient, I am sure they rival big old nasty oil filled transformers. Maybe we could put it to the question : Which needs mo re cooling, an "iron" transformer or a DC to DC or even AC convertor.

Big IGBTs switching at 100 KHz or two, PWMed to make 60 Hz running into a s mall inductor at each major tap, or even at each house. The DC can be kicke d up or down quite easily these days and like alternative energy we might r each a crossover point. Let's put it this way, if I am not mistaken there i s more silicon in the Earth than iron.

So it is possible that Edison was right, but at the wrong time. We'll proba bly never know because I think it will take the technology another twenty y ears. That is because it doesn't just have to beat the old way, it has to b eat the old way enough to pay for the switchover.

That was Edison's assertion in court or wherever they argued the point. He pointed out that it was used for the electric chair IIRC. Of course then we didn't have bleeding heart liberals. If we did, there might be no electricity in this country.

Talk about conjuring up an image of a different history...lol

You are merely talking about the load it presents, not the physiological ef fects. I have some experience in this field as it intrigued me so I experim ented with a function generator. The body feels lower frequency AC more tha n high.

I know it does not seem to stand to reason but it is true. Take and find a sensitive spot for the electrodes. You might need an amplifier but I had a Wavetek 111 which put out about 50 volts/600 ohms.

Put the thing on say 2 KHz and crank up the voltage until it becomes slight ly uncomfortable. Now turn down the frequency with the amplitude constant. And that line of Waveteks IS constant. They do not use a Wein bridge and AL C, they generate a sawtooth first and then "distort" it into a proper sine wave. Actually I am impress by the circuit, not so much its topology (well some) but the fact that they got the thing down to 0.5 % THD. I can see wh y nobody else wanted to do it that way and just stuck with the Wein bridge. There are three adjustments, one for each "layer" of odd order distortion it imposes on the sawtooth wave. Another way to put it is I am not all that impressed that it woks, but I am impressed that they got it to work so wel l. Nice for some things but not for audio testing. My rig (HP339A) floors a t 0.0016 %. I hope that is good enough for now. You know how them audiophil es are.

But it is true that the human body acts resistively with a little capacitan ce as far as the load, but the perception I would have to almost say it is an inductor, except for one thing.

Instead of lowering the frequency, switch it to square wave. It feels not o nly about twice as strong, but distinctly different. Of course now you are putting in quite a component at the 20th harmonic which might be working a bit with that capacitance.

It is just more of that weirdness that has not yet been explained. The worl d is full of it.

** Such a simplistic model is nothing like accurate when it come to electric shocks. This article covers the facts fairly well.

.... Phil

From there :

own.3 This lowers the body's resistance to current flow greatly. The result is an increase in the amount of current that flows with any given voltage. Areas of skin breakdown are sometimes pinhead-sized wounds that can be eas ily overlooked. "

You should be able to remember old tellys. With tubes. Here, it is a damped half sine of 70 KHz at a rate of 15,734. On the cathode of a tube telly, t here was approximately 7 KV at the anode of the damper tube. This is not DC , this is that pulse I described approximately.

That sombitch burned through my finger all the way to the bone. It was a ho le with a little brown patch around it. There was no blood at all. Damnthin g was about precauterized.

I got a raise soon after that. Just for the hell of it.

The true list is: Faraday, Henry, Edison, E. Thomson, E. Houston and Tesla.

Marconi was 15 years old when Tesla finished his works: " Later Marconi set up long-distance demonstrations, using a Tesla oscillator to transmit the signals across the English Channel." "Tesla replied, "Marconi is a good fellow. Let him continue. He is using seventeen of my patents."

Maxwell was interesting in electromagnetic induction. His hipotheze that light is also EM was discedited by L. Lorenz (not H. Lorentz). Hertz did transformer with the coil in form of the ring.

The end of the story is: " It wasn't until 1943?a few months after Tesla's death? that the U.S. Supreme Court upheld Tesla's radio patent number

645,576.". From:

The names Edison, E. Thomson, E. Houston are mentioned here:

" Thomson and Houston conducted a series of careful experiments where they discovered that the sparks actually carried a charge".

When Tesla discovered the same he started reading the science papers and have found the names: Faraday, Henry, Edison, E. Thomson, E. Houston. S*

Wow! That chap in figure 5 appears to be in some considerable peril! ;->