power inverters

Well SnoMan, in looking at the thread, I guess that I am also outdated. I retired after 40 years in aerospace electronics (Calif) and never heard of using 'V' instead of 'E'. Oh well, as long as everybody can communicate I guess that it is OK. I'm sure glad that I retired before the kids screwed things up.

: >Yes it should be E, not V, but every other site switches. : >NASA uses V. All of my grandfather's (who was a master : >electrician for the Newton Falls Paper Mill for over 35 years) : >books, some copyrighted in 1935, that I have use E, as did he : >when he taught me. And if you really dig you canl find some sites : >and books that use U. : >

: : : "E" is the correct term to use not "V". E= I over R, not V = I over : R. E kinda stands for "electromotive force" which is aso known as : "voltage " or "potenail". : ----------------- : The SnoMan :

: >>> I grew up in Europe and learned about 30 years ago that U=I*R and : >>> P=U*I as the basic ohms laws : >>>

: >>> as in Volts=Amps*Ohms and Watts=Volts*Amps : >>>

: >>> Or maybe im just getting old :-) : >>>

: >>>

: >>>

: >>

: >> Naw, they just keep changing the conventions to confuse everybody. : >> Heck, when I was in school, current still flowed from negative to : >> positive. Not anymore. : > It all depends upon how you want to look at it. Negative to positive : > is called "Electron Flow" and positve to negative is called : > "Hole Flow". The net effect is exactly the same regardless of : > how you do it. : >

: >

: : True. But my electronics courses consisted of vacuum tube theory. Hole Flow : didn't come along until transistors and PNP and NPN junctions. The : scientists had to come up with another theory because electron flow being : neg to pos didn't work out when dealing with solid state devices. Cracks me : up. : : RCE

For sure. I had a hell of a time trying to figure out 'Holes' versus Electrons.

: :

There is a good example on the following page. Just click "Start" to run the Java applet.

So that's why it's so hard to get sensible answers out of engineers.

I work for a electric utility. The NACA/IBEW/CWA accredited apprenticeship programs for linemen, construction electricians, meter electricians,and relay electricians *all* are taught E=I*R.

Communications electricians usually don't get an apprenticeship. Most of us are military/community college trained and/or self taught (me all three). Every one of those teach the E.

Think of the "Wheel"

E ______ (I'm not going to spend the time to make to make an ASCII wheel)

I * R

Cover the one you don't know and the wheel shows the other side of the equation to answer that.

You beat me to that one. My work truck has a permanent mount 400W inverter for running test equipment and small stuff like battery chargers for tools and radios. There's not enough of the 2400W/4000W peak load inverters to go around, so we have those made up with short cables and do the "lift the hood - hook up the leads" trick when we need to use musclewatts. It's a small pain in the ass but it beats trying to stuff one of the big ones in an already stuffed Dodge or GM minivan.

Thanks for catching the efficiency issue. I'd already posted when I caught my mistake.

On Sun, 09 Apr 2006 17:20:31 -0400, RCE rearranged some electrons to form:

I think it was Ben Franklin that came up with what is now known as "conventional" current, which flows from positive to negative. It's just a mathematical concept that makes it convenient to do circuit analysis. At that time, the concept of two different states of electrostatic charge was known.

In solid-state physics, a "hole" is a missing electron from the crystalline stucture of a semiconductor. Because there is an electron missing, there is a net positive charge at that point, so the concept is accurate.

An electric field knocks electrons from their places, thus creating a flow of electrons (otherwise known as a current). This is true of a semiconductor, or a conductor (metallic wire).

On Sun, 09 Apr 2006 20:50:13 +0000, SnoMan rearranged some electrons to form:

Who knows, I might have designed the radio you soldered together.

hehehehehe

BTW, I visited your site. Nice job on that Torino.

RCE

On Sun, 09 Apr 2006 20:10:35 -0400, RCE rearranged some electrons to form:

Thanks!

On Sun, 09 Apr 2006 20:50:13 +0000, SnoMan rearranged some electrons to form:

No, John, what I REALLY like is to take bloviating pontificators like you down a notch when they show their ignorance and blame it on typographical errors. Typo, huh? Twice? Yeah sure. Maybe you should stick to snowplowing.

Oh and by the way, "be little" is one word, not two.

what is an electron? hehe