Electronics versus plumbing?

[Biggles]

A while ago, a friend of mine asked me to try and teach him a little about electrical theory. He had no experience with electrical circuits, so I tried to associate electrical current flow with water flow, which as a plumber he understood very well. I started off with the basics like a heavy gauge cable will allow more current through, just as a large bore pipe would allow more water flow, and a resistance was like a narrow pipe. A capacitor behaved like a water storage tank, and switches were like stop valves. Then I began thinking deeply about how similar electrical and plumbing theory really is. Even a non return valve is like a diode. A pump is akin to a generator, a motor is like a hydraulic drive etc etc. Can anyone come up with more equivalents between the two subjects? Maybe I just have too much spare time on my hands!
Alan.

[Panrock]

What is a plumbing inductor?

Steve

[julie_m]

A turbine with a heavy flywheel. It slows the flow down until it gets up to full speed, and tries to keep pushing things along even after no more water is hitting the turbine.

[Scimitar]

Originally Posted by Panrock

What is a plumbing inductor?

Heat exchanger?

[turretslug]

Kirchoff's voltage and current laws certainly have relevance to a plumbing situation....

[Ed_Dinning]

A leak in plumbing gets you wet. An Electrical leak can get you dead!

Ed

[Panrock]

If you fall into a big enough water tank and panic, you can drown.

Steve

[julie_m]

Depends. When it was a water main the best part of a metre across that blew, sending bits of road surface flying into nearby houses and cars and turning a street into a river, it was lucky nobody got killed .....

[Panrock]

There's a technology analogous to electronics called 'fluidics', isn't there?

I guess the frequencies involved must be limited to the low audio region though, even using miniature parts.

Steve

[stevehertz]

Well, no matter, but the one thing I do know is, the day you invite a plumber into your house to do work is the day leaks begin. I've never noticed a similar, parallel pattern with electricians?!

[Steve_Bell]

A basic observation: there is no return circuit needed in plumbing (e.g. neutral wire)...

[Radio Wrangler]

Inductance is analogous to the momentum of moving water. Try to close a valve instantly and you get a pressure shock transient.

Try to block electrical current flow in an inductor and you get a voltage transient.

As a plumber, he'll know water hammer well enough.

Look up the 'hydraulic ram pump' it's the analogue of a switch mode boost converter! and it's self-oscillating. The ram pump was attributed to the Mongolfier brothers (their day-job, ballooning was their hobby) and multiple ones along the river operated the pulsing fountains at Versailles.

David

[Panrock]

Looking a little farther afield... I guess the main difference between plumbing and gas technology is the latter's compressibility. The speed of sound in a gas is less too. Does this mean a Gas Computer would be slower than a Water Computer?

Steve

[Biggles]

Going back to the water tank/capacitor, I dare say that a water tank with a diaphragm across it, isolating the two halves of the tank flow wise, but flexible enough to pass vibrations through would behave somewhat like a capacitor passing an AC signal. A very small tank would only pass high frequency pulses of water pressure from one side to the other, where as a large tank would pass lower pulses more easily. At rest, the two halves of the tank would not affect each other, just as a capacitor with DC applied would not pass current. A diaphragm with a small hole in it would equate to a leaky electrolytic, and an overflowing tank would be the same as having too much voltage applied to the capacitor, and it breaking down.
Alan.

[kevinaston1]

Electronics Today International ran a tutorial series "Water Logic" showing how the various gates could be manufactured using pipework; no idea of the date, late 70's early 80's probably.

I also have a hazy recollection of Douglas Self doing some work on this.


Kevin

[emeritus]

Victorian and Edwardian text books often introduced the subject using the hydraulic analogy. I seem to remember that Scott-Taggart used it in his 1933 book "Manual of Modern Radio".

[M0FYA Andy]

Originally Posted by Steve_Bell

A basic observation: there is no return circuit needed in plumbing (e.g. neutral wire)...

Yes there is, the sewage system!
With a nominally fixed amount of water available, it all goes round in a circle, although I guess our usage is small beer compared with the weather.

OK, I'm going off topic...……...

Andy

[Richard_FM]

I heard that capacitors being known as condensers was due to early ideas of electricity flowing like water.

[Herald1360]

Originally Posted by kevinaston1

Electronics Today International ran a tutorial series "Water Logic" showing how the various gates could be manufactured using pipework; no idea of the date, late 70's early 80's probably.

The plumbing in old French hotels sometimes behaved like this. Turning the tap on in one room meant no water in another

[Phil G4SPZ]

The 'hydraulic accumulator' - a closed cylinder where water flows in or out from the bottom, trapping and compressing air above it - behaves rather like an electrical accumulator or rechargeable battery. I guess the electrical device got its name from the hydraulic device. Virtually all combi boilers now incorporate an accumulator or 'pressure vessel' which has taken the place of the traditional 'header tank'.

At least one manufacturer makes a 'water fuse' designed to detect a higher than normal water flow rate (say as the result of a burst pipe) and isolate the supply.

The water analogy works quite well, but only up to a point. I can't think of an electrical equivalent of temperature, for instance, and there's no hydraulic equivalent of transformer action where a magnetic field is involved. Having said the latter, I've seen a water wheel driving a crank-driven piston pump, generating high pressure water at low flow rate from low pressure water at high flow rate, thus qualifying as a transformer with mechanical rather than magnetic coupling between primary and secondary.