patrick.net

It can decay that way via beta decay. In the process a neutron becomes a proton and beta particle.

Headset, I am tired and typed that in error. diodes are wonderful electrical check valves that can make the DC. I do think however the rectifiers do use capacitors to do it. Don't make my head hurt by asking me to turn a sine wave into a DC signal and then back to a semisine signal :) It made my head hurt years ago.

If you reduce the voltage, the amps go up and that ball will kill you quite quickly.

Same way powerlines don't melt. The voltage is high and then stepped down. AMPs and Voltage are related to each other. You can lower one by raising the other.

This is proof that nuclear engineering is easier than EE. All I had to do was count neutrons and learn some crazy math that required me to get a minor in math. Some differtial equations, diffusion theory, and transport theory were easy to solve.

EE have to do an evil phaser dance to figure out what is going on in a circuit. I hear they even eat their young :o

It can decay that way via beta decay. In the process a neutron becomes a proton and beta particle.

I see, thus is stays a 233 isotope. I suppose that right after the U-233 is formed, it immediately experiences fission from collisions with any remaining neutrons?

I realize the "capacitor" verses "diode" was more a typo. That's why I wrote "you mean diodes" rather than "your mistaken."

http://en.wikipedia.org/wiki/U-233

Read this for a good run through on the black magics of nuclear physics. This show the trick of turning stuff into other stuff. The true art of alchemy.

U233 has a longer half live than the daughter isotopes and will last a while. It will last long enough to ge given a chance to fission on its own when a neutron gets inside it nucleous.

Same way powerlines don’t melt. The voltage is high and then stepped down. AMPs and Voltage are related to each other. You can lower one by raising the other.

The reason power lines do not melt because resisitance is low. Heat generated by current flow is related to resistance. It is true that the step down transformer decreases the volts and increases the amps, but that is a side issue. If the power company feed 220 volts (what is delivered to the house "fusebox") into the line at the source, they would have a very short transmission distance. Think of the hose analogy. Open the nozzle and get high flow at low pressure. Can't squirt very far. Tighten the nozzle and you have less water flow (amps), but with enough pressure (volts) to squirt across the street.

Nut,

Good article. Thanks.

I agree with this as well. Not sure why you disagree though with the melting, I will have to check. I completely agree that the 220 volts wouldn't go far that's why it is transmitted at high voltage to step down at the source. My understanding is that was the objection to AC until they discovered that transformers could be used. It is just like how cable in the house has to be a certain thickness or it will melt. I will try to find a source but we are now literally at my borderline of knowledge in this area.

I've heard the hose analogy before about volts being the pressure inside but you just conceptulized something for me about the spray so I thank you.

Headset, I believe it is Joule heating which is reduced by increasing voltage.

http://en.wikipedia.org/wiki/Electric_power_transmission

Again, we are moving into uncharted territory for me so I don't feel comfortable pushing any further than sharing this link.

Malcom,

If I have a wire of a given resistence, increasing the voltage will cause the wire to heat up. That is counter to using high voltage to stop wires from melting.

If I have a wire with high enough resistance, high amps with low volts will not flow through it. If I increase the voltage to make amps flow (even though the amps are decreased), the wire will heat up.

Thicker cables have lower resistance than thin cables of the same material. AC does have that "skin effect," and benefits from stranded wire, but my point still applies.

Actually, my main point was that I want off-the-grid houses to evolve to max use of DC appliances, since I thought that converting from battery DC to house wire AC and back to internal appliance DC was wasteful.

Malcolm,

I posted the above before you last post. I was unaware of the joule heating factor. Good link.

That makes sense. Also, the low volts not flowing makes sense as that goes back to the battery example. Sort of like being constipated I guess, not enough pressure to push through.

I knew thicker cables have less resistance hence minimum guages for power requirements, I didn't know about stranded wire. I always thought that was to get the same effect from less materal, now you have enlightened me on another thing since I didn't know it was the surface area that mattered. Interesting.

I partially agree on the last point. I hope I helped you there. I don't see any reason to go from DC to AC to DC. I say DC to DC step it up or down with a voltage regulator (pretty sure that is the right component, but you know what I mean, the little gadget that you can plug into the lighter adapter and click whether you want 6, 9, 12, 14..etc. volts.) and if needed use an inverter on a seperate circuit for AC power. A pure sine wave inverter gets expensive, but the modified sine wave inverters are reasonable. Their only limitation is that they create noise on stereo equipment. I think you will find the power loss to be very negligible.

Here is another thing that you might find interesting. One of my business partners had an idea I thought was pretty creative. He proposed designing an EV charging jack as part of a typical home solar inverter. He believes you can rapid charge an EV with the DC current directly from the panels. Again, the concept is simply adding a seperate circuit to the same string, therefore you wouldn't have the waste you are talking about using AC to charge a DC EV. The excess of course (when there is no car there) would go the normal route back out to the utility as AC. The flaw of course being most EVs will be charged at night, but I thought it was a creative idea. Maybe commercial business could offer EV charging from their solar systems to their employees or customers. I like to try to find a potential for an idea instead of just shooting it down.

LOL, I was typing and didn't see your last post either.

Nutty, is it the volts or the amps that will melt an underrated wire?

technically, I believe it is the current density

Power = (I^2)*R (resistance heating)
dV = I*R

I=current
R=Resistance

If you can raise the voltage, you can reduce the line losses. This is why high lines are stepped up to the thosands of volts that they run at. The reason for this is the decreased ampes on the line. The power is carried away on the wave action of the electron going back and forth.

http://www.theoildrum.com/node/4636

We have the solution to this problem.

Looks like my man Krugman has won the nobe prize for economics.
Always a good read when he is not wonking politics.

Can we start a new thread?
Just so I don't have to wade through this garbage?

Guys, I have not been reading this thread yesterday, but take it from an EE with quite a few years of additional education on top of the basic degree (if you catch my drift):

There has been a few misleading and/or errant statements made about certain electrical topics in this thread yesterday. I'm not quite in the mood to dissect all of it, but let me just clarify one or two points.

First, I should caution that there are many different ways of saying the same thing here, but let me just try to say it one way and see if that makes sense to everyone.

The reason that high voltage in a transmission system does not translate into hot and melting wires is that the VOLTAGE DROP along the wire is quite small. Note that there is a difference between the voltage drop along the wire and the voltage drop across the load that is connected between the two (or more) wires. The voltage drop across the load does (mostly) productive work. The voltage drop along the wire is plain loss.

More detail:

The reason that high voltage transmission is more efficient is that lower current is required to transmit tghe same power (P=V*I, V goes up, I goes down, for constant P). The loss in the wire is P(loss)=I^2*R, with a lower I than before.

Of course, there is more to the story than this, because there also are losses in the insulating medium (or "dielectric") between the wires (air, rubber, oil in transformers, etc etc). At some point, diminishing returns are going to set in when you increase the voltage, because the insulation gets prohibitive, the wires have to be spaced too far apart, etc etc etc.

Now, as I had mentioned a few months ago, one of the reason that DC transmission systems can be more efficient than AC , is that dielectric losses tend to be lower when there is a constant electric field rather than an alternating electric field. The latter is jerking the bound electrons in the insulator around quite a bit, and energy is lost. This is all a bit folksy a way of saying it, but you get the idea.

I agree with Fuzzy about current density. It is just an alternative way of saying the same thing as I just did. And I will defer to Neutron on most things nuclear :-).

Oh, I did not see Neutron's 1:35 am post. Also correct.

Duke,

I can agree that discussion of energy and energy conversion systems is a bit OT, but it sure has a profound effect on the economy in general and housing matters as well.

I think those exchanges are very worthwhile.

Duke,

Yeah, congratulations to Krugman, one of many decent economists that have advocated buying preferred equity rather than buying bad assets.

Duke Says:
Can we start a new thread?

It's up.