why not change conventional current to electron current?

[miguelvp]

True and x/32 or x/64 will have an exact binary representation using 5 or 6 bits  of the mantisa respectively.

That's exactly why I meant it was convenient, also it's convenient geometrically for carpenters without the use of rulers and such.

[Brumby]

The metric system also uses water to define mass: 1 litre of water weighs has a mass of 1kg.

Unfortunately, this has not been true for over a century. When the kg was defined as the mass of the International Prototype Kilogram, it stopped being possible for anyone to reproduce the kg in their backyard.

Well, it started out that way - and it's still close (1.000028 litres)

[IanB]

SI doesn't facilitate anything versus Imperial units. It's just an arbitrary re-scaling of quantities.

Actually, it does. It puts similarly dimensioned quantities on a common footing and allows calculations to be done without awkward conversion factors appearing everywhere. The most troubling for new students is the appearance of g_c in many formulas to convert between mass and force (and woe betide you if you accidentally multiply by g_c when you need to divide).

Beyond that, consider calculating the compressor horsepower to compress 100 cfm of air from 15 psi to 100 psi. Suddenly you have got hp, ft, lb_f and minutes all mixed up in one formula. There is going to be a "magic number" in that formula that converts all the incompatible units. You'd better have a good memory for conversion factors. Every formula will have a different magic number in it.

[miguelvp]

The metric system also uses water to define mass: 1 litre of water weighs has a mass of 1kg.

Unfortunately, this has not been true for over a century. When the kg was defined as the mass of the International Prototype Kilogram, it stopped being possible for anyone to reproduce the kg in their backyard.

Well, it started out that way - and it's still close (1.000028 litres)

The international prototype was achieved by equating the mass of 1 liter of distilled water at a bit lower than 4 degrees C  when water is at its highest density at one Atmosphere of pressure, probably at sea level.

That's still true. However there are efforts to change that using Planck's constant as well as the Avogadro initiative.

Edit: but if you make a container that holds 1dm^3 of distilled water and chill it to 3.984 C you'll get a kilo if you are by the beach

[CatalinaWOW]

SI doesn't facilitate anything versus Imperial units. It's just an arbitrary re-scaling of quantities.

Actually, it does. It puts similarly dimensioned quantities on a common footing and allows calculations to be done without awkward conversion factors appearing everywhere. The most troubling for new students is the appearance of g_c in many formulas to convert between mass and force (and woe betide you if you accidentally multiply by g_c when you need to divide).

Beyond that, consider calculating the compressor horsepower to compress 100 cfm of air from 15 psi to 100 psi. Suddenly you have got hp, ft, lb_f and minutes all mixed up in one formula. There is going to be a "magic number" in that formula that converts all the incompatible units. You'd better have a good memory for conversion factors. Every formula will have a different magic number in it.

Exactly.  While the sizes of the units are arbitrary in both systems, the relationships are maintained in the SI system.  A bit of confusion is added when convenience/honor units are added (things like Pascals) but it is still easy to get back to the base units.  And thence my gripe about measuring torque in the units of gm-cm.  You can't multiply gm-cm by rotation rate and get units of power.  You have to remember one of those "magic numbers", and remember that it is necessary.  A step back towards the morass of doing physics in (you pick the name) English/American/traditional units.

[TimFox]

The metric system also uses water to define mass: 1 litre of water weighs has a mass of 1kg.

Unfortunately, this has not been true for over a century. When the kg was defined as the mass of the International Prototype Kilogram, it stopped being possible for anyone to reproduce the kg in their backyard.

The international prototype was achieved by equating the mass of 1 liter of distilled water at a bit lower than 4 degrees C  when water is at its highest density at one Atmosphere of pressure, probably at sea level.

That's still true. However there are efforts to change that using Planck's constant as well as the Avogadro initiative.

Edit: but if you make a container that holds 1dm^3 of distilled water and chill it to 3.984 C you'll get a kilo if you are by the beach

I was taught that the original definition of the gram was in terms of a cubic centimeter of water (at maximum density), and that a liter was defined 1000 cubic centimeters.  When the prototype kilogram became the new definition, the liter was still defined in terms of 1 kg of water, since the chemists needed to use it, and therefore the liter (non-SI unit) is slightly different from 1000 cubic centimeters.  The SI unit of volume is merely the cubic meter, which does not have a name.
There was a non-serious suggestion to name the liter/minute the "Falstaff", in opposition to re-naming the "cycle per second" as the "Hertz".
Well, it started out that way - and it's still close (1.000028 litres)

[hamster_nz]

I'm afraid you are going to lose that one. It is widely accepted in the English speaking world that "America" is short for "United States of America" when the context is a country (and by the way, I am not American).

You wouldn't happen to be from the USA?    "Mexicans are not Americans"    "Brazil is Un-american!"  

(Yes, this is light-hearted trolling, for anybody who misses it...)

Down here we use "The States" to refer to nearly anywhere you have to go through US customs and America is a more generic term for North America... "I'm flying to America for a week skiing at Whistler" would raise no eyebrows.

Hawaii is an odd special case. You should really give it independence and save all the confusion

[rs20]

And thence my gripe about measuring torque in the units of gm-cm.  You can't multiply gm-cm by rotation rate and get units of power.  You have to remember one of those "magic numbers", and remember that it is necessary.

A. That "magic number" is g, which we all know.
B. It's far more common to want to know how much weight a motor can hoist than how much mechanical power it's putting out. If you have a torque in N-cm, you need that same "magic number" (g) to convert the force back into grams!!

My point is, it's context specific; completely rejecting gm-cm is ridiculously inflexible. Please don't pretend that you're objectively right by cherry-picking operations which are easier starting from N rather than grams; I could sit here cherry-picking operations starting from grams and we'd never get anywhere.

[KL27x]

Robertson screws are far superior to Philips.
https://en.wikipedia.org/wiki/List_of_screw_drives#Robertson
No slippage and the screw stays firmly on the screwdriver at almost any angle.
Unfortunately, they are virtually unknown outside Canada. 

The Robertson screw has a different set of compromises, is all. Screwhead must be fairly deep. The bit gets seized/stuck in screw with significant torque (say you are removing a lot of high torque screws.. you may have to tap/wiggle each screw to get them off the bit, similar to a hex head). The angle between the driver and screw must be straight. And the screwhead impression must be in a particular set of sizes.

One of the greatest advantages of Phillips is that you can drive a Phillips head screw with the wrong Phillips head bit. They overlap to a large degree. With one or two Phillips head bits, you can do nearly anything. If you have the wrong size Robertson head, you are SOL. I don't see Roberson as doing anything that hex or torx doesn't accomplish better. (A Robertson "allen key", for instance, would need a room to make at least a 90 degree arc to be useful, compared to a hex head). Also with a phillips, you can also drive a screw at a slight angle between the screw and driver.

And it's known in the USA, just fine. I'm curious if it is actually the most common type of screw in Canada.

[Dinsdale]

    You don't have to change anything. Conventional flow is hole flow from pos to neg. Electron flow is from neg to pos.
They occur simultaneously.

    I always think in terms of electron flow. Current flow is in the opposite direction of all those schematic symbols.
Every tech. I know thinks in those terms. Every engineer I know thinks in conventional mode. It helps the engineers get
their math polarity correct. But I know the polarities because I know which way the current is flowing. Confusing? It
just seems natural to me.

    Just go to the freeway. Look at all the parking spaces traveling South in the North-bound lane. South is the real direction
of travel.

[pmbrunelle]

Robertson screws are far superior to Philips.
https://en.wikipedia.org/wiki/List_of_screw_drives#Robertson
No slippage and the screw stays firmly on the screwdriver at almost any angle.
Unfortunately, they are virtually unknown outside Canada. 

The Robertson screw has a different set of compromises, is all. Screwhead must be fairly deep. The bit gets seized/stuck in screw with significant torque (say you are removing a lot of high torque screws.. you may have to tap/wiggle each screw to get them off the bit, similar to a hex head). The angle between the driver and screw must be straight. And the screwhead impression must be in a particular set of sizes.

One of the greatest advantages of Phillips is that you can drive a Phillips head screw with the wrong Phillips head bit. They overlap to a large degree. With one or two Phillips head bits, you can do nearly anything. If you have the wrong size Robertson head, you are SOL. I don't see Roberson as doing anything that hex or torx doesn't accomplish better. (A Robertson "allen key", for instance, would need a room to make at least a 90 degree arc to be useful, compared to a hex head). Also with a phillips, you can also drive a screw at a slight angle between the screw and driver.

And it's known in the USA, just fine. I'm curious if it is actually the most common type of screw in Canada.

I think the self-holding to the screwdriver is a good feature of Robertson. Makes things less clumsy. If you want to take off a screw that's stuck, I just tap the screwdriver on something.

Robertson is great because of the taper. This means that regardless of tolerances, every screw has a tight fit with the screwdriver. The screwdriver must be straight with the screw; but why would you want to drive it crooked?

There are No. 1, 2, 3 Robertson sizes... same as Philips.

Torx or Allen are not tapered. Obviously, to accommodate manufacturing tolerances, there must be some slack between the screw and the driver. So these are not self-holding like Robertson. In part due to the slack, Allen heads are prone to stripping. Torx does not strip, but it still suffers the non-self-holding malaise.

Robertson doesn't strip like Allen, but it strips more easily than Torx.

Philips is tapered too, like Robertson. However, the taper of Philips is more pronounced, so Philips will cam-out with too much torque. Robertson won't easily cam out, so you don't need to push hard on the end of the screwdriver to get a reasonable amount of torque.

Cam-out for mass production is obsolete. Torque-limited screwdrivers exist now; the cam-out doesn't need to be built into the screw head.

With Philips, it's easy to end-up with busted up screw heads because you cammed out, then you need to go over them with a file to be aesthetically pleasing...

Robertson is common in home construction type stuff. Electrical terminals/connections are going to be slotted or Philips. Automotive is Torx, Allen, or external hex (same as USA).

Robertson is my favorite of all. I think it has the right set of compromises. Looks easy to manufacture.

[IanB]

Robertson is common in home construction type stuff.

But Robertson is more or less found only in Canada. It is not common anywhere else.

[timb]

At least it's better than slotted. Anytime I encounter one, I find myself with a strong desire to travel back in time and curb stomp Johannes P. Slotte when he was just an infant.

At least a Phillips screw can be easily held against the bit with a single finger (or no fingers at all with a magnetic bit), but not a slot! The heads get chewed up easily if the bit is too narrow. Then, I find a bit that's exactly the right width, only to find out it's too thick for the slot in the screw! So I go down a size and chew up the head anyway...

Dumb, dirty, ignorant slots.

[TimFox]

For my woodworking, I have switched to Robertson (square-drive) screws.  The self-holding feature is great.
I use them also for larger machine screws, but there is a much better availability of machine screws in Phillips head.  Recently, I have concentrated on truss-head stainless Phillips screws for electronic assembly.  McMaster Carr is an excellent source for machine screws in all shapes, sizes, and material.
In another thread, I mentioned "Reed and Prince" screws, which were used in classic -hp- gear.  They look like Phillips drivers, but there is only one size driver for several head sizes, and the blades are subtly different.  The only place I could find the drivers was the Sears Craftsman website (but not Sears stores), where they were available for about the same price as "normal" Craftsman screwdrivers.  I haven't found them in hex-drive bits.  If you are working on -hp- gear from 1960 to 1980, I recommend this driver.

[KL27x]

But Robertson is more or less found only in Canada. It is not common anywhere else.

I used Robertson screws to build a fence. I just happened to see them at the local hardware store. And I already had two sets of Robertsons bits without even trying. They just commonly come in bit sets, here, it seems to me. (USA). Yeah, it sure is nice for setting/driving the screws. But I haven't gone out of my way to buy any more. (It was slightly annoying having to liberate the drill when the bit got stuck in the head, but the main reason is the standardization thing).

There are No. 1, 2, 3 Robertson sizes... same as Philips.

There are also many more Phillips heads smaller than that for tiny screws where Robertson doesn't work. But my point was that for the range of screws where Robertson's are used, you need 3 bits. For the same range in Phillips head screws, you can use a #2 screwdriver for practically anything. It might not be ideal, but it will probably work.

To touch back on the OP...
I thought the same thing when I first learned about current. Then I experienced how many arbitrary decisions have to be made in making any circuit and doing any microcontroller programming. I still have a hard time. The direction electrons are flowing is no longer a concern. As with any of the other dozens of arbitrary decisions I have to make every day, if it doesn't work like I thought it would the first time, I would switch the direction/logic/#define and try it again.

[CatalinaWOW]

For my woodworking, I have switched to Robertson (square-drive) screws.  The self-holding feature is great.
I use them also for larger machine screws, but there is a much better availability of machine screws in Phillips head.  Recently, I have concentrated on truss-head stainless Phillips screws for electronic assembly.  McMaster Carr is an excellent source for machine screws in all shapes, sizes, and material.
In another thread, I mentioned "Reed and Prince" screws, which were used in classic -hp- gear.  They look like Phillips drivers, but there is only one size driver for several head sizes, and the blades are subtly different.  The only place I could find the drivers was the Sears Craftsman website (but not Sears stores), where they were available for about the same price as "normal" Craftsman screwdrivers.  I haven't found them in hex-drive bits.  If you are working on -hp- gear from 1960 to 1980, I recommend this driver.

When you bought a screwdriver set at Sears in the 1970s-1980s a Reed Prince screwdriver was included.  I bought a few of these sets because between "friends" and family I was always missing screwdrivers.  This is the first mention I have ever seen of where to use one, so I have two or three that always migrated to the bottom of the toolbox where they couldn't get "lost".  Obviously haven't worked with too much HP gear.

[free_electron]

You want to print all the labels to install in all battery powered equipment to swap the + and - ? And then convince the battery makers to do the same ?

Good luck

[Paul Moir]

And it's known in the USA, just fine. I'm curious if it is actually the most common type of screw in Canada.

In construction, it certainly is, with the exception of drywall screws (Phillips) and plumbing (Slot or maybe Phillips).  The rest get thrown into the garbage.  Electrical is still Roberson, though we now get combo slot-phillips-roberston super-easy to strip cheese grade stuff from the 'States sometimes.  Leviton for example.

It used to be common in manufacturing.  If you look at pre-NAFTA appliances manufactured in Canada, you'll find them used almost exclusively.  You also find them in older tube equipment manufactured in Canada for the Canadian market.

The taper in the Robertson generates an interference for a tight fit, making the fastener an extension of the driver.  This is not available in Allen head or (laughably) Torx.
 
You can drive blacks with reds, reds with greens and greens with yellows.  But it defeats the purpose of the interference fit.

[vk6zgo]

You want to print all the labels to install in all battery powered equipment to swap the + and - ? And then convince the battery makers to do the same ?

Good luck

Sorry,"electron which may be readily dislodged from its associated atom",that is a "straw man" argument.
Nobody has suggested that be done.

I,& many others who learnt Electron Flow are quite content with positive being an "attractive" force for electrons.
Even when my old Employer used "Left Hand Rules" in training material to accommodate Electron Flow,it was never suggested + & - markings should be swapped over.

[Brumby]

In this discussion, I hope nobody is considering changing any reference to connections of, say, batteries.  The terminal with the abundance of electrons ready to jump out should always retain the '-' sign.  If not, then there's a fundamental contradiction right there.

... and I still feel the diode symbol is problematic in any thoughts of change.


Some of the lines of what would change and what wouldn't seem to be unclear.  This also indicates a fundamental problem that has the potential for chaos in an unknown number of situations with an unknown severity - and that is the subject matter that has been built on the current convention, which will be further compounded by subject matter that has been built on that foundation.

At times, we've all seen the difficulty people can have learning about electronics - and the explanations and analogies used to try and make it clearer are built on this same foundation.  While I'm not saying every explanation or analogy - or even the majority of them - will be compromised by a change, the fact that there might be is enough (in my book) to worry about where they might occur.  As an example, I will ask this question: "What impact would such a change have on publications like 'The Art of Electronics'?"

[IanB]

This problem is already fixed with nothing more to do.

If I connect a 10 ohm resistor across a 1.5 V battery then a current of -0.15 A flows from the negative terminal to the positive terminal.

Why is it a negative current? Because it's a flow of electrons and electrons are negative. So the calculations work out fine and there is not even any confusion about the electron charge. It's all done and dusted.

[Brumby]

If I connect a 10 ohm resistor across a 1.5 V battery then a current of -0.15 A

The maths might be OK - but I'm also considering the language. For example:

flows from the negative terminal to the positive terminal.

The 'FROMs' and 'TOs' will need to be reversed, or the sentence structure will not match the concept.


Knowing how it all works out makes it easy to comprehend when looking back, but it's going to confuse the newcomers even more than they are now.

[IanB]

If I connect a 10 ohm resistor across a 1.5 V battery then a current of -0.15 A

The maths might be OK - but I'm also considering the language. For example:

flows from the negative terminal to the positive terminal.

The 'FROMs' and 'TOs' will need to be reversed, or the sentence structure will not match the concept.


Knowing how it all works out makes it easy to comprehend when looking back, but it's going to confuse the newcomers even more than they are now.

You realize I had my tongue in my cheek, right?

But even so, I believe there is nothing wrong with the language. Currents and voltages in circuit analysis must be stated with a direction and an appropriate sign applied. In applying KCL, if I say that the sum of all the currents into a node equals zero, then some of the currents must have a negative sign. It's nothing that newcomers don't already have to figure out.

[Brumby]

You realize I had my tongue in my cheek, right?

Not sure.  Probably too many things happening at this end for me to pick up on such subtleties.


I should probably step .. away .... slowly .........

[vk6zgo]

Electron Flow has been around as a concept for a century or so .

In that time,hundreds of thousands of people learnt Electron Flow & the historical reason for the extensive use of Conventional Current Flow & could move easily between  them as required.
Is the current generation of Engineering students easier to confuse than all of those people?

Electron Flow makes it easier to explain the workings of semiconductor junctions & capacitors,Thermionic Emission & Photo-Emission,& their use in vacuum tubes.
A description of capacitor operation based upon Electron Flow is a lot easier to comprehend than silly analogies using fluid & diaphragms.

An enormous quantity of texts on Electrical Engineering use Conventional Current Flow,& are not going to change anytime soon.
An EE should be at home with both concepts.

There are many things which are Conventions,such as North at the top of maps,"clockwise" rotation,etc.

We still use Newtonian Physics,although Einsteinian Physics exist,we use the movement of the Sun across the sky for Navigation,although we know it is us moving,not our Star,we use a "flat earth" model for some antenna measurements.