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Bruce, I consider this to be very well written - Thank You!!!

Electrically Challenged

More great information! Professor Bruce is keeping me in class this issue!

pressure drop is not directly proportional to water flow rate

Dear Bruce - the analogies between water pressure drop and voltage, water flow rate and current, are not quite as simple as your article suggests. Water flow rate is the product of the density, the flow area and the speed.  The speed is proportional to the square root of the pressure drop, as shown by Daniel Bernoulli some hundreds or years ago.

Thus, water flow rate doubles if the pressure drop is quadrupled, not if it is doubled as your article indicates.

Paul E. Sojka

You are right, Paul

Water Analogy...

I've personally never cared for the water analogy anyway, so if Bruce fudged the water thing, it is what it is, and whatever.

Nice to see some basic information for the electronically challenged Bruce.  I hope this is a trend you will continue, eventually delving into more advanced subjects and projects.

Two thumbs way up!

Analogy

The analogy does have its flaws but plumbing is a great way to explain electronics to someone. Valves = transistors, diodes = ball checks, pipe diameter = wire size, pressure tank = capacitor, and on and on.

Bruce, you are showing your mechanic age - carburetor!!! Love it! Real men don't tune a motor with a PC, huh? Step the jets, adjust the float, and rap the throttle a few times. Ah, the good ole days.

Still baffling!

Bruce, I have studied electronics and circuits and protons, neutrons, voltage, current, OHM's law, you name it. In my line of work as a marine technician, we deal with that kind of stuff everyday deciphering problems in todays most sophisticated marine outboards, so I understand, to a degree, what you are talking about. The water analogy, while not entirely correct, is in my opinion the best way to put it to the average person who wishes to understand the basics of anything we do to our models, layout wiring and all related. Was a good refresher course for myself as well.  Just think of sitting in class and studying "what is the valence shell of an atom" and having to come up with the correct answer! Correct me if I am wrong but that is the outer most ring or shell that gives of free electrons. Phew! Anyways Bruce, this is a good primer for basic electronics in our hobby so please delve into it a little farther into the next article or 2.  Definitely want to read some more.

Explaining Concepts

While the water analogy may not be perfect, it does allow the average person to grasp the basic concepts of electronic components. Anyone can understand that if you put water into a bucket with a hole in it, the water will still leak out of the bucket after the water is turned off. Functionally, that is what a capacitor does with electron flow.

The same is true with a small pipe feeding into a larger pipe. Water pressure (voltage) drops in the larger pipe, but the amount of water flow (amperage) stays the same, just as voltage drops across a resistor while the amperage remains constant.

Is the analogy perfect? Of course not, water is not electricity, but for understanding model railroad electronics, it works fine.

Nelson . . .

Had to laugh!

Yes Bruce you are right!  Had to laugh at your response!  All in fun.

Black and white or gray?

The way I like to look at it (another analogy) is that some people think in black and white terms and others think in shades of gray. The way I came to this analogy is I found my wife and I disagreed a lot when describing a situation and what mattered.

We came to realize she is black and white, and I'm gray. To her, either it's great or it sucks - there's not much in between. To me, everything is in degrees - it can be great, good, fair, poor, or lousy. I also see analogies as very useful, she sees analogies as loaded with imperfections and bad conclusions.

Bruce is obviously a gray person, like me. Others of you who are quick to point out the fallacies of the water analogy are black and white.

Reality is, the world needs both. We need the black and whiters to keep us from getting too sloppy and we need the gray people to remind us to lighten up because not everything is perfect.

DCC ex-panation in article

Bruce,

I am finding the article fairly easy to understand and helpful. I wish my physics teacher in school had used analogies - all I can remember him giving us was a whole lot of formulae and getting me lost with it!

I have to adapt some of the American language for English equivalents as I live in Norfolk, England but I am finding the articles interesting, untestable and informative, once again thank you for your articles and look forward to the next one.

Bruce's articles are always

Bruce's articles are always the first I read.  Awesome? No question.  As a returning model railroader I am marching through every article from day one. 

Joe, keep this guy warm!

Regards

Dick Sipp

Good article Bruce!

I'm just waiting for their reaction when you explain a sneak circuit. That ought to be good!

Den

"I'm just waiting for their

Mr.DCC - Basic Electronics

Nice Article.!!

Have you seen the Ohm's Law & Power Triangles?   They make calculating values easier.

Cover the value you want and the formula is shown.

Steve

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My good friend Steve (aka Smokey) was...................

...............the Radio and later IT tech here at Amtrak in Albany where we worked together for over 30 years.  I used to sit in his radio shop watching him fix and build things and when I asked him "how does that work?", he'd get a grin on his face and tell me "It's magic.................."

Hmmm. 

Peter

DCC

I have a few Harbor Freight DVM's that read about 13.6 VAC with NCE DCC systems. Fairly close to what my digital Oscope measures. 

The meter on the 20MA scale works very well for a DCC am p meter using a couple three terminal chips, ZXCT1009 a high side current sense monitor, with a few passive components. Cheap enough and indicates 4.95 amps when the 5 amp booster trips.

A separate DC only LED meter with 5/8 inch digits at the club and can be seen for quite a distance.

Rich