TS Circuit -- Part 2

Yup, I don't remember when it changed but it was 115/230V at some point between those two standards.

It's often called that but it is 480V.

It's the opposite. 277V is a single phase of a 480V phase-to-phase system. This is entirely different than a 120V system (a transformer is required to get there).

Yes, I'd forgotten 117V.

Probably talking past each other. It happens when threads get convoluted.

Actually no different. There is consideration of switching some high voltage lines to DC partially because for the same peak voltage the wires can carry significantly more power.

A big reason for the switch from DC to AC is the ability to efficiently reduce the voltage at point of use, allowing the distribution lines to run at higher voltage with the exponentially lower power losses.

-BR

No, that's not the reason. High voltage DC transmission doesn't have inductive, skn effect or (the same) corona losses. AC has the advantage of cheap transformation from one voltage to another.

The issue at hand is distribution. AC is much easier to transform, so higher distribution voltages are possible.

LOL 480 it is!

Believe it's more when and what voltages were standardized by what was to eventually become NERC...the first standards meeting was held in about 1896(!) and then there were updates to nominal voltages a couple times thereafter -- but, the public consciousness can't be changed; we all grow up with whatever it is we hear and then pass it along with only a few modifying influences gradually adding to the diversity.

That may be now but back then the DC simply did not have the range that AC did.

Cars used to have 6 volt systems but switched to 12 volt so that the cables could be smaller.

Leon wrote in news:Q9idnQchSrQoje3FnZ2dnUU7- snipped-for-privacy@giganews.com:

AC doesn't have the same losses as DC because it can be transferred at a higher voltage. If you sent AC from the generating station to your house at 120V you'd have the same losses as with DC. The wires on the utility pole outside your house are 4600V (or something in that range, different utilities use various distribution voltages).

Today "safe" is considered to be around 12V. I can't think of any situation where you'd consider 110V to be "safe", unless you're comparing it to something like 1200V.

John

Leon wrote in news:YPydndGe9p2PjuzFnZ2dnUU7- snipped-for-privacy@giganews.com:

Sort of. The real reason it was done was because tetra-ethyl lead was invented.

(Tetra-ethyl lead allows higher octane gasoline. Higher octane gasoline allows higher compression engines. Higher compression engines require more power from the starter motor to get them started, which requires more current from the battery. During the 1950's compression ratios went from ~6:1 to ~9:1, which became a problem for both the battery and the cables. Hence the switch to 12 volt electrical systems.)

John

snipped-for-privacy@notreal.com wrote in news: snipped-for-privacy@4ax.com:

Now let's really confuse everyone by talking about the difference between RMS voltages and P-P voltages :-)

John

"Safe" is considered to be anything less than 52V. There was once talk about the automotive industry moving to a 48V battery. The reason for 48V was that it was just below the "safe" limit. Of course it never happened because it would have caused more problems than it solved.

FWIW I was speaking about the time when electricity was just starting to be used in homes. DC was not practical as there had to be way too many generation stations. Only the affluent were served in the early days, they could afford to have/pay for a DC generation station near by.

The wires out side my home on utility poles are maybe 480 volt NOT forty six thousand. Now the voltage on the hi power transmission lines are much much higher but they are not near by and they go to transformer stations where the voltage is dropped and sent to consumers and still more power pole transformers.. The closest transformer station to me is

Not sure I follow.

Both lead and higher octane fuels reduce precognition knock. Lead did not allow higher octane, it boosted the octane. Lead's main feature was that it lubricated the valves, boosting octane was a perk. Hence in the early 70's when unleaded fuel was introduced only vehicles with modern engines could run unleaded fuel with out damage to the valve train.

Knock is caused by a number of reasons, compression being only one of them. Hotter running engines also create more compression and running more advance on the spark timing will cause an engine to run hotter.

In the early 80's American built vehicles had relatively low compression ratio engines, in the 6's, and engine knock was a constant problem. Enter the computers and knock sensors to retard the ignition timing.

When was that talk? No doubt, there is always something in the air but I never read or heard of that back when I was in the automotive business.

I'm sure it was intended to help make vehicles lighter in weight.

Coming soon, evidently

Not every electrical component will switch to 48-volt. Lights, radios, electric windows and door locks, for example, would stay 12-volt. And Delphi?s vision is that vehicles with 48-volt systems would also have a strong regenerative braking system to capture much of the energy lost when a vehicle slows down.

Read more:

Just multiply peak by .707.

Whether AC or DC is safer was Edison's point when he electrocuted an elephant with AC. But DC was a dead by then.

Not necessarily, my Unisaw is 3hp single phase, 60HZ, 230V as are these and countless others:

SawStop

Jet