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Comment: Re:clean drinking water (Score 1) 89

by Technician (#47467237) Attached to: Harvesting Energy From Humidity

With electrolisis and a fuel cell, only the gas carried contaminates could possibly contaminate the drinking water. For quanity and qualityproduced, I'll take the solar solution. The distances traveled and the amount produced are both quite small. In the solar solution, the volume would be much greater and due to the recombining of gasses, much less likely to transport pathagens.

Comment: Re:Is this news? (Score 1) 78

Charged particles are not magnetic. The electric current caused by the electric current creates a magnetic field. Basic electrical magnetic property. There is a magnetic field because there is an electric current traveling through the atmosphere which does impose an electric charge on suspended insulated objects in addition to the induced electric current in conductors on and in the ground.

The amount of induced current is directly related to the rate of flux change producing an AC current provided one end of the conductor is grounded. At the low currents and large area of very long lines, this AC component is relatively low in relation to the DC current brought in at the poles seperated by our earth's magnetic field. A static magnetic field does not induce a current. A steady DC current does build high currents in long suspended conductors.

Even high voltage transmission lines are now protected by adding a resistor to the center tap of a 3 phase transformer to ground to limit induced current. The transformers already MUST have a ground refrence already due to the DC charging of the lines that would happen if there were no ground. This is why transmission lines never use Delta transformer to Delta transformer. One or both ends of a transmission line have a substation with a Y connection with the center tap grounded.

I know of one BPA line that is Delta to Delta, but in addition to this there is a 3 phase Y transformer to nowhere that only porvides the required ground for the line.

Grounding both ends with a low impedance ground is good for lightning strike protection, but bad in a geomagnetic storm. Ungrounded is bad for line charging and lightning protection. UTP network cable is ungrounded at both ends and are subject to high voltage charging in short lengths.

Comment: Re:Is this news? (Score 2) 78

The elevated lines between buildings are rarely protected from a build up of a static charge as routers and bridges were not built with this in mind. On the physical layer, both ends of the wire are terminated into an isolation transformer with no discharge path to ground. This is an installation design fault against the guy that designed the installation. Lightning protection is often a gas discharge tube for a lower breakdown voltage. A high current discharge through a protection device can produce a relatively high ESD pulse through the transformer into the tranciever chip resulting in corrupt data to failures. A link between buildings must include a bleed discharge path to prevent the build up of voltage on the wire, or a shielded wire with grounded shield should be used.

Engineers design systems. A good technician can make them work.

Comment: Time to apply science (Score 4, Informative) 78

Time to apply science to the problem. What is known, what values are involved, and what breaks down.

Long distance transmission lines have two problems when there is a relatively high atmospheric current. They are long conductors feeding transformers that are not designed to shunt large components of DC resulting in core saturation and high current. This is measurable. The first effect noticed was by the railroad when telegraph relays activated and sometimes burned out.

The voltage induced current has two components. 1 Some current was due to the current directly into the long wire. 2 Some current was due to ground potential changing due to high current in the ground.

How to protect? For ground potential issues, simple pairs of wires provide high common mode rejection. This is common with telephone circuits as protection from induced hum and noise from a noisy electrical environment. Overvoltage protection in the form of lightning arresters is the second protection. Most phone loops are relatively short reducing the ground voltage gradient problem to non existant levels. Long distance hops are by Microwave Relay or Fiber Optic, both providing protection from ground gradients and long pick up paths.

Shrink the scale to inside a home by comparison. All internal house wireing is orders of magnatude shorter than transmission lines, CATV, and phone lines. Small DC capible antennas result in very low current if exposed. The home is generally protected by gutters on the eves, mildly conductive building materials such as wood, brick, etc that are not insulated to very low leakage at high voltages such as the insulatin on transmission lines. Net result is the very small currents are shunted by the building itself. Go up on the roof during a geo storm and see if you have any static electricity issues. Probably not.

For homeowners, this is a non issue due to the lack of an effective gathering surface properly insulated to collect enough current to cause any damage. The collector is too small and the leakage path to ground is too high.

Comment: Re:verizon, comcast? (Score 4, Interesting) 81

I was stuck on Comcast when I upgraded from Dialup. Due to the games with non working services, I jumped ship as soon as Qwest offered DSL. Skype, VOIP via SIP, Google Voice/Talk, etc all working fine. I feel for those without the option. Comcast has been trying to win me back, but I'll take the slower DSL speed for everything working properly anyday.

Comment: Re:No. (Score 3, Interesting) 502

Many of the earlier SB cards were known for a fixed clock, regardless of what the software was set for. This limited clock rate was the issue of many complaints of those looking for full 20-20K without artifacts. Once this reputation was cast, the line was considered as consumer grade and not better. Same applied to bit depth. The driver would accept many settings beyond the 16 bit DAC. Other cards had higher clocks and bits, and testing for the card performance showed the true limits.

Link below shows some of the real testing on this card beyond just golden ears. Look at the frequency output of noise and note what is NOT reproduced. Then scroll down a look at the extended frequency response of the cards in the test. SB hit a wall way before the competition.

Comment: D/A is good enoug, but.. (Score 1) 502

Onboard D/A for WAV, MP3, Movies, etc are generally good enough if the noise level is low enough. The biggest difference is in the on board synth. Playing games uses MIDI and the sound card produces the sounds. There are 2 versions. Hardware and software.

Hardware had an on board synth. It can be as simple as an 8 bit video game or as complex as full wavetable sampled sounds. An onboard hardware synth will sound the same on Linux or Windows. If the wavetable synth is XG compatible or similar, the sound is great. If a cheap synth is used it will sound like a casio entry level keyboard or 8 bit videogame.

Some cards use soft synth's with soundfonts. These can be very good sounding with inexpensive hardware as the synth runs in the OS and just sends the bitstream to the card for repoduction. This uses some system resources and requires installing the proper driver to include the synth and soundfont. This can mean great game sound in WIndows, but no sound or missing sound in Linux for games, unless you load a soft synth on Linux, install a soundfont, and enable it through Jack. While the combo does sound great, it is a resource drain.

Now, which is better? Mixed bag here. Some on board sound come in either variety. Same with add on boards.

Comment: Re: Land of the fee (Score 1) 702

by Technician (#47399815) Attached to: TSA Prohibits Taking Discharged Electronic Devices Onto Planes

I second that on the courts. I had to drop off a document for a child case. I stopped at the metal detector and told security I was here to drop of a document, not visit offices, so I had not emptied my pockets. Please call the office of ... to come pick up the document. They objected. I said they can scan the manilla envelope. They complied. I made it clear I had no intention of wasting time for a drop off. It would be much faster for them to step out of the office and accept the delivery.

Comment: Re:$15 LED 3 years ago, haven't bought any since (Score 1) 196

by Technician (#47372857) Attached to: The lightbulb I've most recently acquired ...

I've had mixed results with LED bulbs. They fall into 3 catagories.

1 Poor lumen maintenance.
They dim over time by a large amount. Most often seen in Christmas Lights. My daughter took a string of blue LED's and used them as a nightlight in her room. about 1/2 were totally dead in 6 months. The remainer were all over the map in brighness, but all were much dimmer compaired to a string stored for Christmas used for comparison. Failure rate of decreased brightness by 1/2 percieved brightness in 6 months is 100%. A couple of other low wattage night light bulbs in bathrooms did the same.

2 Infant Mortality
I have had an infant mortality rate on LED bulbs slightly higher than with CFL's. Both are higher failures than traditional name brand incandesceant.

3 Perform well.
Recently I have had more bulbs in this catagory from the name brands. Cheap import bulbs still suffer from the above two. To save energy where the energy cost is the highest, I have them in my Motorhome. To save bulbs where short cycling kill the other types, I have them in bathrooms and utility rooms. With some name brand bulbs, they are slowly creeping into the living areas that have lights on for long periods of time where failures were common. I always write the date installed on the bulbs I use to keep track of their life.

"We learn from history that we learn nothing from history." -- George Bernard Shaw