water analogy- a simple calculator

Yes, a free drop is viscosity effects, if you want to put it that way. pulling on it, to increase velocity will also increase drag, hence eddy current clutches, brakes, dashpots etc., that generate more drag as velocity increases.

Breaking threshold in comparison, would be a PM suck to something requiring minimum tension to move across a magnetic surface, or a solenoid, minimum surface breaking tension.

Maybe we're talking about something else here.

Jamie

Use this stop watch to see how long it takes the flies to make it around the race track, and do so with great alacrity! ;-)

Cheers! Rich

John Larkin:

A very nice definition of culture is "everything you know after you forgot everything".

I've been at grammar school, studying Greek and Latin for five years, French only for two (plus the three already done in middle school) and, guess what, I learned English by listening to the Beatles. Despite of that, after few months in the US, I scored better, in verbal ability, that 75% of the other GRE candidates. And I can still survive in France.

Clearly. But they would be in much worse shape if they did not understand the "hose thing" before starting to make otherwise meaningless calculations.

As I mentioned before, the water analogy should be taught in secondary schools, not university. But, on the first lesson of EE 101, I'd make sure everybody is familiar with it.

Analogies are fundamental to get you there. After, you can forget them.

John Fields:

Because he does not want to. ;-)

How about a big coiled garden hose? Not only looks like an inductor, but the mass of the water in it will give it inductor properties: Hard to get current to start flowing, and once it's flowing, hard to stop or change directions.

Best regards,

Bob Masta DAQARTA v6.00 Data AcQuisition And Real-Time Analysis

They need analogies so they know what equations to borrow from the EEs!

Best regards,

Bob Masta DAQARTA v6.00 Data AcQuisition And Real-Time Analysis

Bob Masta:

HA! [cit.]

The All-Encompassing Garden Hose Analogy!

BTW, what about shorter hoses? Short conductors don't have any inductance, nor capacity (as the hose's elasticity)?

This reminds me that a pipe can also oscillate and transform hydraulic energy into acoustic waves (as in badly done house piping), pretty much like an antenna transfers energy in another domain.

Working with MEs can be fun. Once we had a requirement to furnish a mechanical propeller shaft-rotation counter for a big ship. It was to be a non-resettable veeder-root type indicator, in a sealed box with a window for readout of the counts. It had to count turns in either direction, since the ship runs in reverse now and then. The MEs were stumped, so I invented the mechanical full-wave rectifier. It was simple, a couple of gears and belts and two of those one-way clutch things, essentially an inverter and two diodes. I was surprised they hadn't thought of that.

I've run into similar situations with various scientists and such. Electronic design teaches us all sorts of topological and algorithmic and signal processing tricks that do have useful analogies in other domains.

John

Hydraulic accumulator? That's a pretty lossy inductor equivalent.

John

Grossly different behavior, explained elsewhere. Resistance is more like low-Reynolds number viscoscity.

The only things that resistance and friction have in common is that both are dissipative.

John

I don't want to because the behaviors are very different. You'd have to actually understand friction behavior to see why. Neither static friction nor sliding friction behave like electrical resistance.

John

John Larkin:

What about the air drag of "your" mass hung to a spring?

You know, there are several kinds of friction, most of them due to... electromagnetic forces.

low

Oh the piston thing works nicely for me as a transformer. Thanks.

Did you ever see the variable Vee Belt drive on a snowmobile? George H.

Friction is different than a resistor. (Did you look at the plots I posted?) With friction you get a decay in amplitude that is linear in time. As long as the oscillator is moving it's losing amplitude at a constant rate. For a damping term that depends on velocity you get an exponential decay. Like an RCL circuit.

With electricity the electrons start moving even with the smallest electric field.

I've been racking my brains for a friction analogy in electronics and can think of nothing. Now I'm wondering if you could make some circit that would look "friction like". (An oscillator that decays linearly.)

George H.

Did you look at the plots I posted John? Friction causes a linear decrease in amplitude, not exponential.

George H.

No 'Mutual Inductance' though.

And then just stops.

John

Now you're parsing definitions. I don't consider viscous force to be "friction." Maybe you do. If you do, then some forms of friction behave like electrical resistance and some don't. Enjoy.

John