Global Warming?

[Rob-D]

No. If you had information to convey, why try to leave the listener confused about what your are trying to say?

EE,
You're smarter than that, you're concerned you won't be able to get oven bulbs? Give me something to work with here.

Rob

 

[mostly_gas]

Yes and no, some of the old lathes used those but it depends on the lateral and axial stresses, the main problem is pistons going up and down in cast iron blocks, gears grinding along, rubber seals, etc.

Once again, a mechanical device will never out do and electronic one for simplicity and low maintenance.

Rob

That's why all the 7M Fanuc controls are gone from work, they(controls) were too expensive to repair compared to the productivity of the machine.

 

[Rob-D]

That's why all the 7M Fanuc controls are gone from work, they(controls) were too expensive to repair compared to the productivity of the machine.

That was more of about obsolete parts, and obsolete parts are expensive. Today those circuits could be redesigned for a fraction of the cost. Now the MBTF on stuff is ridiculously long. I can design circuits that will outlast all of us, and I have already.

A good example of mechanical vs. electronic is computerized switching systems. The old panel systems ATT ran took a tremendous amount of man hours to maintain. Panel and stepper systems gave way to computerized systems with one or two people sitting in front of a CRT, way more dependable and maintenance free.

What do you think will last longer, an MP3 with no moving parts or your old cassette deck? Even the famous Nakamichi Dragon couldn't last like the cheapest MP3 player. We were always changing heads on reel to reel decks too.

It's hard to beat the technology curve with old stuff, we may like our old cameras, I loved my Leica M3, but the new stuff is just better. Now you don't mix chemicals to develop film you download pics to your computer. No more stop bath down the drain. Ansel Adams got emphysema from all those chemicals.

The transistor has changed our world, not too many people realize that, without it we wouldn't be having this conversation, medical advances would come to a standstill, energy usage would multiply hundreds of times, and the pollution monitoring systems in your car wouldn't be nearly as effective.

Think about what the transistor has done to reduce mechanical parts. Now you get a brushless DC motor that goes in any direction with no wearing parts except the bearings. With NdFeB magnets it's about 1/3 the size of the old AC washing machine motors, hall sensors do all the control sensing and mosfets do all the DC switching.

How many of you have noticed that now there are no more large transformers in power supplies? That's because of devices like MOSFETS that switch very high currents at very high efficiencies.

At the turn of the last century there was a big battle going on with Tom Edison and George Westinghouse. Nikola Tesla came along and invented the AC motor and with AC being inducible Edison took a nose dive. That's why we have AC in our homes now and not DC. Today, if I had my way all my appliances would be 48 volt DC because of MOSFET's, IGBT's, etc. we don't need the induced current systems we used to have and we can save a bundle on power transformers with all that copper. There will be a time in the future when everyone will generate their own power, no more power line losses and a bullet proof grid.

You can't beat technology, it's just getting industry to use science for the betterment of man and not just for profits. What corporations don't realize is that eventually technology will push them aside if they don't keep up. That's what PV is about, you're not going to stop it, you might slow it down but I have everyday people now asking me about my system. If you think I'm wrong look at the original satellite dishes, only a few people had them now they're smaller and in every home that wants one at a fraction of the cost. Now you stream music free from any radio station in the country. Who would have thought anyone would do that 20 years ago?

Again, the guys here who think they can stick their heads in the sand and stock up on incandescent bulbs are an anachronism that history will leave in its wake.

Technology used right is better for all of us and the planet.

Rob

 

[mostly_gas]

That was more of about obsolete parts, and obsolete parts are expensive. Today those circuits could be redesigned for a fraction of the cost. Now the MBTF on stuff is ridiculously long. I can design circuits that will outlast all of us, and I have already.
Rob

Really, what parts failed?

 

[SPYDERLK]

At the turn of the last century there was a big battle going on with Tom Edison and George Westinghouse. Nikola Tesla came along and invented the AC motor and with AC being inducible Edison took a nose dive. That's why we have AC in our homes now and not DC. Today, if I had my way all my appliances would be 48 volt DC because of MOSFET's, IGBT's, etc. we don't need the induced current systems we used to have and we can save a bundle on power transformers with all that copper. There will be a time in the future when everyone will generate their own power, no more power line losses and a bullet proof grid.
Technology used right is better for all of us and the planet.

Rob

Absolutely, but you will never see everyone generating their own power so AC is here to stay. Step up/ step down is too efficient for DC to compete for transmission. Distance losses will always be a killer with DC.
larry

 

[Redneck in training]

Absolutely, but you will never see everyone generating their own power so AC is here to stay. Step up/ step down is too efficient for DC to compete for transmission. Distance losses will always be a killer with DC.
larry

HVDC (high Voltage DC) long distance transmissions are significantly more efficient and even cheaper than long distance AC transmission. AC long distance lines suffer skin effect when the current is located on the surface of the conductor, they require three conductors. They have inductive and capacitive leakage against adjacent conductors and ground.
DC transmission lines have only two conductors, the current flows trough the whole cross section of the conductor, they don't have capacitive and inductive leakage etc. The biggest problem is changing the voltage. There are several such lines in operation for more that 50 years. The early version had rotational transformers consisting from motor and generator on each end. New installation might have solid state equipment. DC lines could transfer power across the US taking advantage of the fact that in example sun shines in the East four hours earlier than in the west. In other words it would be much easier to share generating capacity across the whole country or continent. DC lines are economically very effective for long distance due to high cost of the equipment used for voltage changing. There are several HVDC project in study or planning state in the USA. Since the DC can transfer power using lower voltage they are often used for undersea transmission lines.

 

[Jim Thompson]

HVDC (high Voltage DC) long distance transmissions are significantly more efficient and even cheaper than long distance AC transmission. AC long distance lines suffer skin effect when the current is located on the surface of the conductor, they require three conductors. They have inductive and capacitive leakage against adjacent conductors and ground.
DC transmission lines have only two conductors, the current flows trough the whole cross section of the conductor, they don't have capacitive and inductive leakage etc. The biggest problem is changing the voltage. There are several such lines in operation for more that 50 years. The early version had rotational transformers consisting from motor and generator on each end. New installation might have solid state equipment. DC lines could transfer power across the US taking advantage of the fact that in example sun shines in the East four hours earlier than in the west. In other words it would be much easier to share generating capacity across the whole country or continent. DC lines are economically very effective for long distance due to high cost of the equipment used for voltage changing. There are several HVDC project in study or planning state in the USA. Since the DC can transfer power using lower voltage they are often used for undersea transmission lines.

I thought that Tesla and Edison resolved the issue over high voltage AC vs DC over 100 years ago. I know that new technologies and conductors could change the equation, I just haven't read anything about it lately. I could see where DC would have some advantages and technologically, changing the voltage shouldn't be insurmountable using inverters and transformers. However, It would be impractical to convert all household appliances and industrial applications to DC.

Jim

 

[Egon]

What do you think will last longer, an MP3 with no moving parts or your old cassette deck? Even the famous Nakamichi Dragon couldn't last like the cheapest MP3 player. We were always changing heads on reel to reel decks too.

Isn't there a difference on how the music may be recorded which may relate to quality of sound?

 

[Redneck in training]

I thought that Tesla and Edison resolved the issue over high voltage AC vs DC over 100 years ago. I know that new technologies and conductors could change the equation, I just haven't read anything about it lately. I could see where DC would have some advantages and technologically, changing the voltage shouldn't be insurmountable using inverters and transformers. However, It would be impractical to convert all household appliances and industrial applications to DC.

Jim

DC has several disadvantages making it impractical for short distances.
1.) the cost of the equipment "transforming" the voltage (inverters) is expensive relative to energy saving.
2.) It is unidirectional. It can be made bidirectional but it would become even more to expense.

For long distances like for across the country where lower losses are worth the expense DC is hard to beat. In fact that is only system (beside some exotic) making cross country possible and practical.

 

[crash325]

DC has several disadvantages making it impractical for short distances.
1.) the cost of the equipment "transforming" the voltage (inverters) is expensive relative to energy saving.
2.) It is unidirectional. It can be made bidirectional but it would become even more to expense.

For long distances like for across the country where lower losses are worth the expense DC is hard to beat. In fact that is only system (beside some exotic) making cross country possible and practical.

Hummm - Sort of sounds like AC, don't ya think.