Direct Question for Boscoe and Fairdeal RE: WIF Probe

[boscoe99]

So its actually an "amp meter" - displaying a result in ohms?

Here's a question I have had for some time:

my tank level gauge (or my trim gauge) -

reacting to the varying resistance of the "sending unit" -

putting aside that the gauge face is labeled "E - F" ( or "Down - Up")

what is the gauge actually displaying: amps? volts? ohms?

Is a voltmeter really a voltmeter or is it really an ammeter?

[fairdeal]

Is a voltmeter really a voltmeter or is it really an ammeter?

that's my question!

(and then I have some faint memory of the word "galvanometer" !?)

[cpostis]

that's my question!

(and then I have some faint memory of the word "galvanometer" !?)

Here's a good explanation of a "galvanometer":

[IMG]GalvanometerPNG by Charles Postis, on Flickr[/IMG]

Be cognizant that this is used in analog meters, not digital.

And don't forget this:

[IMG]ohms-law-illustrated by Charles Postis, on Flickr[/IMG]

Remember "Ohm's Law":

[IMG]OHMSLAW_5 by Charles Postis, on Flickr[/IMG]

Can you calculate current with out both resistance and voltage, no.
Can you calculate voltage without both current and resistance, no.
Can you calculate resistance without both voltage and current, no.

So, in my opinion, an analog meter is simply a calculator. Probably a DMM as well!

Thanks Zeno!

[ausnoelm]

What you say is partially correct, you forgot the fourth bit, wattage or power consumed, voltage can be "figured" out if only wattage and amps are known, ohms law as you depicted is the most commonly used equation in electronics and it takes into account the three most commonly used and known values.

[zenoahphobic]

And of course current is also just calculated!
We cannot measure (nor see etc) current; most people don,t even know which direction it travels in.
We can only detect electrical potential ( in its various names such as emf, volts etc. ) Current of course is derived by drop in electrical potential over a conductor.
So from a mathematical perspective the rule of knowing at least 2 values to calculate a third is somewhat not applicable to electric circuits as you would think; current and resistance and power, are just derived from one known value :electrical potential.

Of course the key to the way we "measure" is that we use the magnetic field produced when a current flows. Mathematically electrical potential and magnetism are really the two variables required to calculate the third.

[cpostis]

What you say is partially correct, you forgot the fourth bit, wattage or power consumed, voltage can be "figured" out if only wattage and amps are known, ohms law as you depicted is the most commonly used equation in electronics and it takes into account the three most commonly used and known values.

Yes ausnoelm you are correct. However, and not to be argumentative, I was quoting Ohm's Law as a reference. The term watt is not part of Ohm's law. In fact it is a different law, Watt's Law.

[IMG]Ohm.Watt by Charles Postis, on Flickr[/IMG]

[zenoahphobic]

In which order did Voltair, Watt, Ohm and Ampere make their discoveries?

[cpostis]

In which order did Voltair, Watt, Ohm and Ampere make their discoveries?

Well, can't say exactly, but here is some "unconfirmed" information on Watt's and Ohm's laws:

01001111 01101000 01101101 00100000 01100100 01101001 01100100 00100000 01101000 01101001 01110011 00100000 01110111 01101111 01110010 01101011 00100000 01101111 01101110 00100000 01110010 01100101 01110011 01101001 01110011 01110100 01100001 01101110 01100011 01100101 00100000 01101001 01101110 00100000 01110100 01101000 01100101 00100000 01111001 01100101 01100001 01110010 01110011 00100000 00110001 00111000 00110010 00110101 00100000 01100001 01101110 01100100 00100000 00110001 00111000 00110010 00110110 00101100 00100000 01100001 01101110 01100100 00100000 01110000 01110101 01100010 01101100 01101001 01110011 01101000 01100101 01100100 00100000 01101000 01101001 01110011 00100000 01110010 01100101 01110011 01110101 01101100 01110100 01110011 00100000 01101001 01101110 00100000 00110001 00111000 00110010 00110111 00101110 00001010 00001010 01010100 01101000 01100101 00100000 01010111 01100001 01110100 01110100 00100000 01110101 01101110 01101001 01110100 00100000 01110111 01100001 01110011 00100000 01110010 01100101 01100011 01101111 01100111 01101110 01101001 01111010 01100101 01100100 00100000 01100010 01111001 00100000 01110100 01101000 01100101 00100000 01010011 01100101 01100011 01101111 01101110 01100100 00100000 01000011 01101111 01101110 01100111 01110010 01100101 01110011 01110011 00100000 01101111 01100110 00100000 01110100 01101000 01100101 00100000 01000010 01110010 01101001 01110100 01101001 01110011 01101000 00100000 01000001 01110011 01110011 01101111 01100011 01101001 01100001 01110100 01101001 01101111 01101110 00100000 01100110 01101111 01110010 00100000 01110100 01101000 01100101 00100000 01000001 01100100 01110110 01100001 01101110 01100011 01100101 01101101 01100101 01101110 01110100 00100000 01101111 01100110 00100000 01010011 01100011 01101001 01100101 01101110 01100011 01100101 00100000 01101001 01101110 00100000 00110001 00111000 00111000 00110010 00101110 00001010

Sorry, had my binary code conversion program running when I pasted it.

Here ya go!!

Ohm did his work on resistance in the years 1825 and 1826, and published his results in 1827.

The Watt unit was recognized by the Second Congress of the British Association for the Advancement of Science in 1882.

[rodbolt17]

and no mention of Kirchoff.

[rodbolt17]

in binary 1+1=0.
what does 8+8 = in octal?
0r 2+2 in hex?
yes I did the training as well.
years ago I was decent at it.
now I simply fix outboards and sterndrives.

[99yam40]

yea, I decided to make a living as a mechanic back in the 70s ,it was simple and I could understand things back then.

life and everything else has become more difficult to understand how things work as the years go by

[zenoahphobic]

yea, I decided to make a living as a mechanic back in the 70s ,it was simple and I could understand things back then.

life and everything else has become more difficult to understand how things work as the years go by

That era, which started in the sixties, was driven by youth revolt wanting to change the world.
For history prior the masses were just told to accept things; much was just magic etc. Education standards increased and more and more explanations were demanded; the inquisitive mind was encouraged and so was technology encouraged to compete. Back then simple had to become complicated, fuel efficiency and pollution control, were two things that arose out of this free thinking time.
Now we are at an era where it is virtually impossible to breakdown technology to its basic components or its roots. We are now becoming more ignorant about things but we are results driven; we want everything possible.
It was easy to describe every detail of an automobile in 1970, but now not.
We admire how a two year old might easily use e.g. an iPad and we think the younger generation know more than we did, but just ask then to explain how an iPad is made and works you will be surprised by the number of blank stares within the younger generation. Write an "app" maybe, actually program a computer: no, because more often than not they are no longer taught this fundamental "how things work", like our generation might have.