EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: VK3DRB on December 12, 2024, 10:06:54 am
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Why do electronics people in Australia still call the AC mains 240V, when it is 230V +10%, -6%. In Australia, all states/territories have transitioned to 230 V standards. :-//
Why is it we still use the archaic imperial system in PCB design, when almost all the world moved to metric decades ago? I do PCB schematics and layout in metric always, but my schematic grid is 2.54mm (0.1") to avoid the dangerous off-grid errors. My Gerbers and drill lists are all in metric. :-//
Why do some component vendors (usually American) provide mechanical drawings only with imperial measurements? :-//
Why don't mechanical drawings in datasheets always reference everything to one origin datum point rather than having annoying time wasting measurements all over the shop? I suspect the authors had never made a component in Altium. :-//
Why don't some component manufacturers provide 3D step file models? If I have to choose a part, often those who have a 3D model is the deal maker, assuming other important parameters are equal. :-//
Why can't electronics engineers disco dance? :-//
Any other oddities we electronics people still have to live with, other than ourselves?
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Why don't mechanical drawings in datasheets always reference everything to one origin datum point rather than having annoying time wasting measurements all over the shop?
I agree, that is infuriating.
I've even seen connector footprint drawings where there is no route from one reference to another.
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My two biggest frustrations are:
1) People who claim metric for dimensions is more logical; and
2) People who thing metric is more accurate.
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Why do capacitors always have a line indicating negative except when it's a tantalum which have a line for positive.
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Why don't mechanical drawings in datasheets always reference everything to one origin datum point rather than having annoying time wasting measurements all over the shop?
I agree, that is infuriating.
I've even seen connector footprint drawings where there is no route from one reference to another.
It is infuriating, but speaking to a mechanical engineer, the idea is to avoid a possible conflict in the drawing by making everything dependent upon only one other datum. Otherwise it is possible to create conflicting dimensions.
In the world of CAD though, surely such conflicts could be validated out by the software. And perhaps a list of absolute coordinates relative to some other coordinate could be provided. Having to draw a microSD connector out using these dimensions was incredibly painful.
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My two biggest frustrations are:
1) People who claim metric for dimensions is more logical; and
Metric is more logical, for the simple reason that every scale is related by powers of ten, whereas we have 12 inches to a foot, 3 feet to a yard, 1760 yards to a mile, etc. However, there is no advantage in using metric for PCB design because that uses decimal inches (eg 1.27 inches). No feet and yards there.
2) People who thing metric is more accurate.
Really? I've never heard of that before. Does anyone really think that? I wonder if they mean more precise rather than more accurate, but of course that is nonsense, too. You can dial in any level of precision you want with either system.
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Why can't electronics engineers disco dance? :-//
Speak for yourself; I won first prize for it at the school end-of-term disco when I was eleven
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Why don't mechanical drawings in datasheets always reference everything to one origin datum point rather than having annoying time wasting measurements all over the shop?
I would hope and expect the mechanical measurements reflect the manufacturing techniques and hence the manufacturing tolerances.
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Why can't electronics engineers disco dance? :-//
Speak for yourself; I won first prize for it at the school end-of-term disco when I was eleven
That was then; this is now; can you still get down and boogie?
And what's with that precious non-standard text color you insist on using?
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Why don't mechanical drawings in datasheets always reference everything to one origin datum point rather than having annoying time wasting measurements all over the shop?
I agree, that is infuriating.
I've even seen connector footprint drawings where there is no route from one reference to another.
It is infuriating, but speaking to a mechanical engineer, the idea is to avoid a possible conflict in the drawing by making everything dependent upon only one other datum. Otherwise it is possible to create conflicting dimensions.
In the world of CAD though, surely such conflicts could be validated out by the software. And perhaps a list of absolute coordinates relative to some other coordinate could be provided. Having to draw a microSD connector out using these dimensions was incredibly painful.
You forgot the major factor. Good dimensioning includes tolerances, and the tolerances in various parts of a product are not all to a single reference point.
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Australians (and other members of the Commonwealth) may use imperial measurements, but in America we use "US conventional units".
There are some differences between the two systems, but both are defined in terms of SI metric units.
The Empire is long gone, but the United States are still here.
The 0.1 inch = 2.54 mm grid isn't hard to use.
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Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
[attachimg=1]
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The Empire is long gone, but the United States are is still here.
There; FIFY.
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I don't think "Electronics oddity we still have to live with" is a nice way to describe someone in this forum.
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Hmm; anyone in particular you have in mind? or is "someone" here used in the general sense?
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My two biggest frustrations are:
1) People who claim metric for dimensions is more logical; and
Metric is more logical, for the simple reason that every scale is related by powers of ten, whereas we have 12 inches to a foot, 3 feet to a yard, 1760 yards to a mile, etc. However, there is no advantage in using metric for PCB design because that uses decimal inches (eg 1.27 inches). No feet and yards there.
2) People who thing metric is more accurate.
Really? I've never heard of that before. Does anyone really think that? I wonder if they mean more precise rather than more accurate, but of course that is nonsense, too. You can dial in any level of precision you want with either system.
I won't delve deeply into #1. Seems to me dimensions that are easily divisible by 2,3,4, other numbers, and decimal units are more logical and useful. What divisions one uses is a choice in our system, but not in metric. The metric basic unit is no more logical than our basic unit. Both are arbitrary.
As for #2. Yes, I have heard people at work say metric was more accurate. Even if they really meant precise, it is no more precise either. In a practical sense, if you look at dials on manual machines, the smallest division in metric is usually 0.05mm. On our machines, it is 0.001", or about twice as precise, assuming the numbers mean anything.
I mentioned it as an odditie, not to argue about metric v. imperial/American. In my own life, I use what's conventional and convenient, e.g., in physical sciences, metric; and in the garage and kitchen psi, ft-lb, inches (both decimal and fractional), tablespoons, etc.
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The Empire is long gone, but the United States are is still here.
There; FIFY.
"States" is plural.
"The United States of America" is singular.
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I don't think "Electronics oddity we still have to live with" is a nice way to describe someone in this forum.
"Oddity" is a feature or a person. "Oddball" is an insult to a person.
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The Empire is long gone, but the United States are is still here.
There; FIFY.
"States" are plural.
But "the United States" is not; it's generally recognized by USAns (of which you are one) as a single entity, therefore singular.
The UKOGBANIs treat it as plural, not us.
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Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
I always use the "zigzag" for resistors, since is is suggestive of the function, just as the loops are suggestive of coils (inductors).
The blank rectangle is useful for arbitrary components or impedances.
Unfortunately, the rectangle is considered standard in Europe.
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I mentioned it as an odditie, not to argue about metric v. imperial/American. In my own life, I use what's conventional and convenient, e.g., in physical sciences, metric; and in the garage and kitchen psi, ft-lb, inches (both decimal and fractional), tablespoons, etc.
Yes. One area where I find our (non-metric) system much easier to deal with is carpentry and woodworking, at least for most work where the highest precision is 1/16". Much easier to deal with a sheet of plywood that's 4' x 8', rather than the entirely unwieldy 2440mm x 1220mm. And divisions in working with wood are not easier in units of 10; even dividing a space into equal subunits is easily done in non-metric units by well-known tricks.
Of course, I realize that part of my preference here is due to growing up using that system of measurement, but it still feels more suitable to me than the alternative.
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The Empire is long gone, but the United States are is still here.
There; FIFY.
"States" are plural.
But "the United States" is not; it's generally recognized by USAns (of which you are one) as a single entity, therefore singular.
The UKOGBANIs treat it as plural, not us.
There are other "United States", including Mexico (officially United Mexican States in translation).
The "United States of America", abbreviated USA, is the specific term for the country of which I am a citizen.
The US Constitution seems to have only one clause in which the plural or singular is relevant. Usually, "United States" is followed by "shall" which does not distinguish singular and plural. However,
"Treason against the United States, shall consist only in levying War against them, or in adhering to their Enemies" (Article III, section 3)
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There are other "United States", including Mexico (officially United Mexican States in translation).
The "United States of America", abbreviated USA, is the specific term for the country of which I am a citizen.
The US Constitution seems to have only one clause in which the plural or singular is relevant. Usually, "United States" is followed by "shall" which does not distinguish singular and plural. However,
"Treason against the United States, shall consist only in levying War against them, or in adhering to their Enemies" (Article III, section 3)
Yes, yes, but what you're arguing here is pure sophistry. Everyone, at least everyone west of Nova Scotia, recognizes "the United States" or "the US" as "the United States of America", so there's no need for the fine distinction you're proposing.
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Why can't electronics engineers disco dance?
Cause were either busy out the back trying to kick some piece of kit back into life or too knackered after being up half the previous evening rebuilding stuff that mr dj blew up at the last gig but only remembered last night.
One oddity that me and many others have pondered is why do ceeform ratings jump instead of flowing nicely, 16A, 32A yep fine,but then 63A and 125A,why not 64A and 128A.
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Like shutter speeds that go 1-2-4-8-15-30-60-125-250-500-1000? Although that's always made sense to me ...
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There are other "United States", including Mexico (officially United Mexican States in translation).
The "United States of America", abbreviated USA, is the specific term for the country of which I am a citizen.
The US Constitution seems to have only one clause in which the plural or singular is relevant. Usually, "United States" is followed by "shall" which does not distinguish singular and plural. However,
"Treason against the United States, shall consist only in levying War against them, or in adhering to their Enemies" (Article III, section 3)
Yes, yes, but what you're arguing here is pure sophistry. Everyone, at least everyone west of Nova Scotia, recognizes "the United States" or "the US" as "the United States of America", so there's no need for the fine distinction you're proposing.
And you are being pedantic. Since Article III, Section 3 calls "the United States" plural, then so may I.
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And you are being pedantic. Since Article III, Section 3 calls "the United States" plural, then so may I.
But Tim, that was written back in the 18th century.
Do you still refer to it as the "Conftitution of the United ftates"?
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And you are being pedantic. Since Article III, Section 3 calls "the United States" plural, then so may I.
But Tim, that was written back in the 18th century.
Do you still refer to it as the "Conftitution of the United ftates"?
The letter that you find amusing is not "f", it is a "long s" which differs from an "f".
Typically, the long s is used in the middle of a word, and the short s (which is the only one you use) is used at the end of a word.
https://blog.thepreservationlab.org/2024/01/what-say-you-a-brief-look-at-the-long-s-and-its-usage
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The letter that you find amusing is not "f", it is a "long s" which differs from an "f".
Typically, the long s is used in the middle of a word, and the short s (which is the only one you use) is used at the end of a word.
I know, I was just needling you.
I still to this day can't help mentally pronouncing it "the conftitution of the united ftates" whenever I see that writing (what, did the Founding Fathers all have speech defects?). I do find it amusing from my 21st C. vantage point.
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Why do capacitors always have a line indicating negative except when it's a tantalum which have a line for positive.
Very good question. I see no logic in it. But I learn the lesson many years ago when I reversed a tantalum thinking the strip was negative. Burnt a hole right through the PCB and set off the fire alarm.
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Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
Actually it is a good idea, because I can embed the resistor package inside the resistor symbol. Here is an example of 0402's. It saves real estate on the schematic.
[attachimg=1]
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Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
I always use the "zigzag" for resistors, since is is suggestive of the function, just as the loops are suggestive of coils (inductors).
The blank rectangle is useful for arbitrary components or impedances.
Unfortunately, the rectangle is considered standard in Europe.
And Australia. It is olde school to use the zig zag. As I mentioned above the rectangle does have benefits.
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There are other "United States", including Mexico (officially United Mexican States in translation).
The "United States of America", abbreviated USA, is the specific term for the country of which I am a citizen.
The US Constitution seems to have only one clause in which the plural or singular is relevant. Usually, "United States" is followed by "shall" which does not distinguish singular and plural. However,
"Treason against the United States, shall consist only in levying War against them, or in adhering to their Enemies" (Article III, section 3)
Yes, yes, but what you're arguing here is pure sophistry. Everyone, at least everyone west of Nova Scotia, recognizes "the United States" or "the US" as "the United States of America", so there's no need for the fine distinction you're proposing.
And you are being pedantic. Since Article III, Section 3 calls "the United States" plural, then so may I.
The United State of America is a Federation, although they state "united" in the name, so it seems that it has a degree of duality.
The Commonwealth of Australia on the other hand, although it is also a Federation, is referred to as "it", or sometimes as "She"-----go figure!
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Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
Back in the day, draughtsmen drew all schematics by hand.
It was much easier to produce a rectangle, instead of the zigzag.
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Australians (and other members of the Commonwealth) may use imperial measurements, but in America we use "US conventional units".
There are some differences between the two systems, but both are defined in terms of SI metric units.
The Empire is long gone, but the United States are still here.
The 0.1 inch = 2.54 mm grid isn't hard to use.
Imperial measures are long gone in Australia for most everyday commerce, the UK are still using some measures, & a lot of "nuts n' bolts" from India are still Imperial.
Of all the measures, the only real difference between Imperial & US conventional is volume, where the former has pints, quarts, gallons etc larger than the latter.
As a result, an Imperial "44 gallon drum" is a US "55 gallon drum.
On the other hand, such a drum would be labelled as a "200 litre" drum, which makes conversion easier between a country using Imperial & one using US measures.
As both countries also deal with Metric countries, they will each only need their existing conversion table.
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Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
Film vs wire wound.
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Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
Back in the day, draughtsmen drew all schematics by hand.
It was much easier to produce a rectangle, instead of the zigzag.
When I draw a circuit freehand, I can draw a zig-zag resistor in one continuous movement.
I'm a big fan of a symbol being representative of the function. To me, a box doesn't suggest anything in particular in itself - only what is defined for it. To me, that is a step of abstraction your brain has to bridge before you can start "seeing" the circuit in full.
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Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
Film vs wire wound.
Wire-wound are quite inductive and unsuitable for a lot of RF applications. Plus they are relatively huge. I used mainly 0402 size resistors in most of my work, which are the most common these days in general, occasionally 0603 and others, and even 0201 on occasions. They are all film. 0402's are the practical limit of my hand soldering skills, although I have hand soldered 0201s... very time consuming and difficult for me to do damned 0201s.
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Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
Film vs wire wound.
Wire-wound are quite inductive and unsuitable for a lot of RF applications. Plus they are relatively huge. I used mainly 0402 size resistors in most of my work, which are the most common these days in general, occasionally 0603 and others, and even 0201 on occasions. They are all film. 0402's are the practical limit of my hand soldering skills, although I have hand soldered 0201s... very time consuming and difficult for me to do damned 0201s.
I came over schematics(TV, IIRC) where the wire wound resistor was drawn as zigzags, and the film resistor as rectangle.
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On the other hand, it is possible to put in too many zigs and zags when drawing resistors, as in the old-tyme style:
[attachimg=1]
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Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
Actually it is a good idea, because I can embed the resistor package inside the resistor symbol. Here is an example of 0402's. It saves real estate on the schematic.
(Attachment Link)
Exactly this. Some also insert 1 or 3 zeros for 0 Ohm resistors at the middle of the rectangle. Pretty informative, especially in large schematic.
I however have a sympathy for zigzag resistor representation. A little easier when someone draw the circuit by hand. Also first resistors in physicist labs were wire-wound ones so resemblance is very clear. From functional aspect resistors should be represented as little flames ^-^
Wire-wound are quite inductive and unsuitable for a lot of RF applications. Plus they are relatively huge. I used mainly 0402 size resistors in most of my work, which are the most common these days in general, occasionally 0603 and others, and even 0201 on occasions. They are all film. 0402's are the practical limit of my hand soldering skills, although I have hand soldered 0201s... very time consuming and difficult for me to do damned 0201s.
0201s can be a pain. And not due to soldering skill (pretty easy doable when you have whatever microscope), but because they are veeeeery easy to lose. Exhale in wrong direction will send your components to whatever direction and I guarantee that you will not find them anymore. My work room have a dozen of these somewhere scattered around.
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There are other "United States", including Mexico (officially United Mexican States in translation).
The "United States of America", abbreviated USA, is the specific term for the country of which I am a citizen.
The US Constitution seems to have only one clause in which the plural or singular is relevant. Usually, "United States" is followed by "shall" which does not distinguish singular and plural. However,
"Treason against the United States, shall consist only in levying War against them, or in adhering to their Enemies" (Article III, section 3)
Yes, yes, but what you're arguing here is pure sophistry. Everyone, at least everyone west of Nova Scotia, recognizes "the United States" or "the US" as "the United States of America", so there's no need for the fine distinction you're proposing.
And you are being pedantic. Since Article III, Section 3 calls "the United States" plural, then so may I.
The United State of America is a Federation, although they state "united" in the name, so it seems that it has a degree of duality.
The Commonwealth of Australia on the other hand, although it is also a Federation, is referred to as "it", or sometimes as "She"-----go figure!
The USA is a "Federal Republic". The Constitution, ratified in 1788, replaced the original "Articles of Confederation" which had established a Federation.
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Why don't mechanical drawings in datasheets always reference everything to one origin datum point rather than having annoying time wasting measurements all over the shop?
I agree, that is infuriating.
I've even seen connector footprint drawings where there is no route from one reference to another.
Not to mention footprints showing distances between pad edges, not centres
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Any other oddities we electronics people still have to live with, other than ourselves?
Why are relay footprints drawn in bottom view (instead of top-view)?
Why isn't there a connector which is perfectly right for the project at hand?
And I second the frustration about footprint measurements not having an origin. This seems to be a problem with mechanical people in general. Every time I get a drawing for an odd-shaped PCB, I need to hunt for the origins, circle centers, etc in order to create the board outline.
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Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
Film vs wire wound.
this is nonsense, most film resistors are spirals.
It only makes sense for a composition resistor. Ceramic, carbon or possibly a small fraction of film resistors... exotic ones.
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Any other oddities we electronics people still have to live with, other than ourselves?
Why are relay footprints drawn in bottom view (instead of top-view)?
They often used valve bases, and there was no point of having a top view of valve pins.
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Speak for yourself; I won first prize for it at the school end-of-term disco when I was eleven
[...] And what's with that precious non-standard text color you insist on using?
Just another holdover from when he was eleven.
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Australians (and other members of the Commonwealth) may use imperial measurements, but in America we use "US conventional units".
There are some differences between the two systems, but both are defined in terms of SI metric units.
The Empire is long gone, but the United States are still here.
The 0.1 inch = 2.54 mm grid isn't hard to use.
Imperial measures are long gone in Australia for most everyday commerce, the UK are still using some measures, & a lot of "nuts n' bolts" from India are still Imperial.
Of all the measures, the only real difference between Imperial & US conventional is volume, where the former has pints, quarts, gallons etc larger than the latter.
As a result, an Imperial "44 gallon drum" is a US "55 gallon drum.
On the other hand, such a drum would be labelled as a "200 litre" drum, which makes conversion easier between a country using Imperial & one using US measures.
As both countries also deal with Metric countries, they will each only need their existing conversion table.
Until 1959, when the US went metric but forgot to tell anyone, the US conventional inch was very slightly different from the Imperial inch.
The older US definition was 1 meter = 39.37 inch, but the Imperial and newer US definition is 1 inch = 2.54 cm (both ratios defined as exact).
This was done to harmonize US and UK inches. The difference is approximately 2 ppm.
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My two biggest frustrations are:
1) People who claim metric for dimensions is more logical; and
2) People who thing metric is more accurate.
https://www.youtube.com/watch?v=EUpwa0je6_Y (https://www.youtube.com/watch?v=EUpwa0je6_Y)
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Any other oddities we electronics people still have to live with, other than ourselves?
Why are relay footprints drawn in bottom view (instead of top-view)?
They often used valve bases, and there was no point of having a top view of valve pins.
Vacuum-tube pins were always numbered clockwise seen from the bottom (where the components and wires went).
Clockwise from the bottom persists into DIP IC pinouts and most (not all) similar semiconductor-package pinouts.
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Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
I'm European and I like them rectangle >:D, not that sawtooth garbage.
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... but the Imperial and newer US definition is 1 inch = 2.54 cm (both ratios defined as exact).
Hey, some irritating nitpicking coming up! I'm pretty certain it is 25.4mm, not 2.54cm. Can I have the "Pedant of the Day" award?
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... but the Imperial and newer US definition is 1 inch = 2.54 cm (both ratios defined as exact).
Hey, some irritating nitpicking coming up! I'm pretty certain it is 25.4mm, not 2.54cm. Can I have the "Pedant of the Day" award?
That's reserved for someone asking whether X is "hard metric" or "soft metric".
Hard metric ceramic tiles are, say, 150mm, whereas soft metric tiles are 154mm. Convert the latter into Imperial units, and you'll see why.
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Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
Film vs wire wound.
this is nonsense, most film resistors are spirals.
It only makes sense for a composition resistor. Ceramic, carbon or possibly a small fraction of film resistors... exotic ones.
Of course, especially the vast majority of the currently sold ones: chip SMD
/sarcasm
On the more serious note, the film resistors precede the laser trimming, which gave the round-spiral form of the current THD/MELF resistors. Long time ago(80's), I worked with flat, untrimmed THD thick film resistors.
And to answer the question in your other tread: look for non-inductive thick-film resistors.
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look at what non inductive means, it is often just cut a little differently
I meant uncut. No trim.
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... but the Imperial and newer US definition is 1 inch = 2.54 cm (both ratios defined as exact).
Hey, some irritating nitpicking coming up! I'm pretty certain it is 25.4mm, not 2.54cm. Can I have the "Pedant of the Day" award?
Utter nonsense. 25.4 mm = 2.54 cm = 0.0254 m EXACTLY.
The actual formal document https://www.nist.gov/system/files/documents/2017/05/09/frn-59-5442-1959.pdf (https://www.nist.gov/system/files/documents/2017/05/09/frn-59-5442-1959.pdf) defined the new US conventional length in terms of the yard, which is subdivided in the same manner as 1 yard = 36 inch.
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Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
Film vs wire wound.
this is nonsense, most film resistors are spirals.
It only makes sense for a composition resistor. Ceramic, carbon or possibly a small fraction of film resistors... exotic ones.
No TH film resistors are spirals. Many are helices. There is a difference between a spiral and a helix.
There are interesting TH film resistors, such as Caddock MS non-inductive units https://www.caddock.com/online_catalog/mrktg_lit/TypeMS.pdf (https://www.caddock.com/online_catalog/mrktg_lit/TypeMS.pdf) that use a "serpentine" pattern to minimize inductance.
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look at what non inductive means, it is often just cut a little differently
I meant uncut. No trim.
Exactly: SOME(not all) of the non-inductive thick-film resistors are non-trimmed; IIRC, there is a company which offers non-trimmed thick film SMD resistors, but don't remember the name.
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Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
Film vs wire wound.
this is nonsense, most film resistors are spirals.
It only makes sense for a composition resistor. Ceramic, carbon or possibly a small fraction of film resistors... exotic ones.
No TH film resistors are spirals. Many are helices. There is a difference between a spiral and a helix.
There are interesting TH film resistors, such as Caddock MS non-inductive units https://www.caddock.com/online_catalog/mrktg_lit/TypeMS.pdf (https://www.caddock.com/online_catalog/mrktg_lit/TypeMS.pdf) that use a "serpentine" pattern to minimize inductance.
i consider serpentine a spiral its just planar. If you follow the path, it ends up being a wave form of some kind. the box is pretty clear that its uniform. The zig zag drawing is accurate to most resistors unless their composition or speciality uncut ones. A single notch anywhere turns it from _ into a U of some kind. A composition resistor is pretty accurate to a box shape, while any cut resistor is a zig zag of some kind.
maybe we should just draw what the resistor actually looks like in the diagram. :-//
The problem is that wire wound ones look identical to air core inductors. Perhaps color can indicate material, if its copper or lossy.
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I consider the zig-zag pattern an indication of function, not geometry.
The rectangle merely indicates an object with two wires, not very specific.
In mathematics, a spiral is normally a planar figure: e.g., a regular spiral has a local radius proportional to angle and a logarithmic spiral has a local radius that increases exponentially with angle (the angle is proportional to the logarithm of the radius).
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There's absolutely no need to differentiate resistor types (i.e., wirewound, composition, power, etc.) by use of different schematic symbols. So far as the schematic is concerned, a resistor is a resistor. Any differences are pointed out on the schematic (or on the parts list) as text descriptions: "5W ww", "2W 1%", etc. No need to add more confusion to what's already a plethora of symbols to be read.
And the zigzag catches the eye--"ah yes, that's a resistor"--more readily than an anonymous rectangle does.
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And the zigzag catches the eye--"ah yes, that's a resistor"--more readily than an anonymous rectangle does.
Because that's what you are used to. It's like the ANSI/DIN/IEC logic gate symbols, if you have exclusively used one for a long time then reading a schematic that uses a different standard may not immediately intuitive.
Mechanical drawings don't reference everything to one origin because it would make tolerancing very difficult. In the vast majority of designs the distance between specific features is of significant importance and may be require much tighter tolerances than the positioning of those features in relation to other, unrelated features.
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Those who draw resistors as rectangles should at least insert the proper color bands for us old timers. >:D
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And the zigzag catches the eye--"ah yes, that's a resistor"--more readily than an anonymous rectangle does.
Because that's what you are used to. It's like the ANSI/DIN/IEC logic gate symbols, if you have exclusively used one for a long time then reading a schematic that uses a different standard may not immediately intuitive.
Mechanical drawings don't reference everything to one origin because it would make tolerancing very difficult. In the vast majority of designs the distance between specific features is of significant importance and may be require much tighter tolerances than the positioning of those features in relation to other, unrelated features.
Having dealt with systems from the US, Europe, and Asia during my career, I certainly recognize the rectangle as a symbol for a resistor.
However, the zigzag for resistors, loopy-loops for inductors, and parallel bars for capacitors are better specific codes for their functions.
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Having dealt with systems from the US, Europe, and Asia during my career, I certainly recognize the rectangle as a symbol for a resistor.
However, the zigzag for resistors, loopy-loops for inductors, and parallel bars for capacitors are better specific codes for their functions.
As a European who was working when the change from zig-zags to boxes happened, I can say our reaction was WTF!
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As a European who was working when the change from zig-zags to boxes happened, I can say our reaction was WTF!
Was that around the same time "they" changed mhos to Siemens?
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As a European who was working when the change from zig-zags to boxes happened, I can say our reaction was WTF!
Was that around the same time "they" changed mhos to Siemens?
And kilocycles to kiloHertz.
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As a European who was working when the change from zig-zags to boxes happened, I can say our reaction was WTF!
Was that around the same time "they" changed mhos to Siemens?
And kilocycles to kiloHertz.
And Jars to Farads.
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Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
Back in the day, draughtsmen drew all schematics by hand.
It was much easier to produce a rectangle, instead of the zigzag.
When I draw a circuit freehand, I can draw a zig-zag resistor in one continuous movement.
I'm a big fan of a symbol being representative of the function. To me, a box doesn't suggest anything in particular in itself - only what is defined for it. To me, that is a step of abstraction your brain has to bridge before you can start "seeing" the circuit in full.
I was brought up on "zigzags" & like you, they are my default when I draw schematics
Draughtsmen are "a different kettle of fish", as they don't draw "freehand".
Their drawings are formal, they drew hundreds of them, so they used drawing aids & so on.
I once had a "drawing aid" with various shapes, including "zigzag" resistors-----the result of using such aids is a worse zigzag than you can do by hand.
Another complication in Europe is the older German predilection for drawing transformer windings as "zigzags", or sometimes "square wave" shapes.
The rectangles were standardised in many countries worldwide, but the reasons for them are no longer fully valid, as computers can draw as many perfect "zigzags" as your heart could desire.
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Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
I'm European and I like them rectangle >:D, not that sawtooth garbage.
Ditto, but you won't stop them from using these zigzags, ".1uF" for "100nF" and inches everywhere. Oh well. :popcorn:
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Ditto, but you won't stop them from using these zigzags, ".1uF" for "100nF" and inches everywhere. Oh well. :popcorn:
So tell us, why is 100nF superior to .1μF?
I actually kinda hate nF. Have to take out paper and pencil every damn time I see that to figure out what the value is. (Old skool here.)
Hey, at least we're no longer using "mmF" ... or calling them "condensers" ...
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look at what non inductive means, it is often just cut a little differently
I meant uncut. No trim.
"Non-Inductive" resistors is an old term for wirewound resistors which were specially wound so as the inductance was largely self cancelled. That works up to around 100kHz---above that they are still inductive enough to cause problems.
Carbon composition resistors were much closer to Non-inductive, although they had other problems.
Early "carbon film" resistors were trimmed using a lathe-like device, & were inductive.
Many years ago, the Instructor at Tech School demonstrated the difference between a daggy old composite & a nice new Philips carbon film resistor, using a "Q" meter.
To our surprise, the carbon composite came out on top, with the carbon film looking more inductive than resistive at HF frequencies.
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Ditto, but you won't stop them from using these zigzags, ".1uF" for "100nF" and inches everywhere. Oh well. :popcorn:
So tell us, why is 100nF superior to .1μF?
It's just easier and less error-prone to stick to integer values. It is an ISO convention to use intervals of 10^3, which is great because it is totally consistent:
milli (10^-3), micro (10^-6), nano, pico, femto, ato (10^-18)
kilo (10^3), mega, giga, tera, peta, exa (10^18)
I realise you know all that, but an integer comprising one to three digits followed by the relevant suffix seems like a really clean and elegant system, which is why I wrote it out. After all, you are happy with picoFarads, so why not nanoFarads?
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It's just easier and less error-prone to stick to integer values.
Now that actually makes sense.
But I still think that a lot of electronics conventions like these are on account of undue paranoia, like the fear of Xeroxes:
I've seen that as the justification for that silly "xRy" convention (e.g., 6R8K instead of 6.8K), because people are afraid of that little dot disappearing when the schematic gets copied a few times. I suppose that might have happened back in the Stone Age.
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I'm surprised nobody mentioned how the arrow in the symbol for a diode or bipolar transistor points opposite the way the electrons actually flow. It got corrected for the symbol for a MOSFET, then "uncorrected" for the symbol for an IGBT...
I've seen that as the justification for that silly "xRy" convention (e.g., 6R8K instead of 6.8K), because people are afraid of that little dot disappearing when the schematic gets copied a few times. I suppose that might have happened back in the Stone Age.
I still follow that convention when drawing schematics by hand. The dot is prone to getting smudged away on paper. Such a practice is obsolete when drawing it on a tablet, hopefully whatever software that comes to convert those hand drawn schematic images to proper schematic files will understand that...
I have also seen that convention used on higher power resistors.
I realise you know all that, but an integer comprising one to three digits followed by the relevant suffix seems like a really clean and elegant system, which is why I wrote it out. After all, you are happy with picoFarads, so why not nanoFarads?
The whole "nanophobia" in capacitor values is something I don't understand. 2.2nF is much more readable than 0.0022uF.
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I'm surprised nobody mentioned how the arrow in the symbol for a diode or bipolar transistor points opposite the way the electrons actually flow. It got corrected for the symbol for a MOSFET, then "uncorrected" for the symbol for an IGBT...
Wellll ... the consensus seems to be among the electronics "community" that we visualize current flow in the "conventional" sense (i.e., from positive to negative), not in the strict physics sense of electron flow.
Which, BTW, apparently doesn't work at all as most people think of it: I've read (can't put my finger on the exact reference at the moment) that in reality, electrons can take a very long time to actually travel through conductors; years, in some cases if I remember correctly.
Have to dig up some stuff from the intertubes on that now.
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... but the Imperial and newer US definition is 1 inch = 2.54 cm (both ratios defined as exact).
Hey, some irritating nitpicking coming up! I'm pretty certain it is 25.4mm, not 2.54cm. Can I have the "Pedant of the Day" award?
The Metrication Board in OZ was very hot on always using mm, instead of the "deprecated" cm.
They didn't even like metres much---so if I want to buy a 2.5 metre piece of wood, I have to order a 2500mm piece.
The idea seems to be tied up with people maybe confusing 2.5m with 25m due to the decimal point.
Of course, we pay for things with decimal currency, & nobody makes mistakes.
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... but the Imperial and newer US definition is 1 inch = 2.54 cm (both ratios defined as exact).
Hey, some irritating nitpicking coming up! I'm pretty certain it is 25.4mm, not 2.54cm. Can I have the "Pedant of the Day" award?
That's reserved for someone asking whether X is "hard metric" or "soft metric".
Hard metric ceramic tiles are, say, 150mm, whereas soft metric tiles are 154mm. Convert the latter into Imperial units, and you'll see why.
A lot of tiles in Australia are 180mm x 180mm.
Hold them up against an old 6"x 6" tile & you are battling to see the difference.
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During my graduate studies in physics, most dimensions (in that ballpark of sizes) were calculated in cm, but the machine shop worked in mm.
Both of us could handle it.
Separately, a useful way to abbreviate 6800\$\Omega\$ is 6K8, not to be confused with the vacuum tube of the same name.
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The idea seems to be tied up with people maybe confusing 2.5m with 25m due to the decimal point.
I'm going to coin a new term here: punctophobia.
(Not to be confused with Punktophobia, which is irrational fear of German radio equipment.)
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https://www.youtube.com/watch?v=JYqfVE-fykk (https://www.youtube.com/watch?v=JYqfVE-fykk)
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Regardless of the merits or lack of merit for various systems of units, the situation of having more than one system in widespread use is a problem:
- Gimli Glider (https://en.wikipedia.org/wiki/Gimli_Glider)
- Mars Climate Orbiter (https://en.wikipedia.org/wiki/Mars_Climate_Orbiter)
On a less epic scale, when I'm getting measurements for furniture items that my wife wants some descriptions provide the measurements in US customary units and some in metric. Therefore I end up with notes that I need to put far too much work into to sort out. I don't think this ever made it through to getting a non-fitting piece of furniture, but it's possible that I've suppressed the memory. I can't recall a specific instance, but I'm pretty sure I have made cuts (wood, paper, whatever) using the wrong units. Nothing of much consequence to life, limb, or finances - irritating nonetheless.
On a tangent, @wraper's SNL clip reminds me of this observation made years ago by Abe Simpson:
The metric system is a tool of the devil! My car gets 40 rods to the hogshead and that's the way I likes it.
(Abe is spending WAAAAY too much on fuel)
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I'm surprised nobody mentioned how the arrow in the symbol for a diode or bipolar transistor points opposite the way the electrons actually flow. It got corrected for the symbol for a MOSFET, then "uncorrected" for the symbol for an IGBT...
That arrow isn't indicating what you think it is. The way oversimplified (and probably technically inaccurate if you're a pedant) is that the center "terminal" with the arrow on it is actually the base (or substrate) of the MOSFET. In three terminal mosfets, the base is tied to the source, and the PN junction between the substrate and the source and drain forms a diode - which is what that arrow and the connection typically shown in the schematic symbol is indicating, not the direction of current flow through the device when it is "on". Or stated differently: it's indicating the body diode.
If you find a schematic symbol that doesn't have the three "internal terminals" shown on the schematic and have it drawn more like a transistor, you'll find the arrow matches the direction you'd expect on a bipolar transistor.
You can, on occasion, find a 4 terminal mosfet, in which case the substrate is on another pin and needs to be tied to source for it to work as expected. The schematic for that just brings out the base/substrate to another pin.
One other note that people miss is that the diode commonly drawn across the diode (connecting to source and drain) indicates that the body diode is rated for repeated avalanche operation. Or, if you just want to think about it more "schematically", it's just like a zener was placed across the FET. But-one shouldn't trust that the correct symbol was chosen that matches the device.
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The metric system is a tool of the devil! My car gets 40 rods to the hogshead and that's the way I likes it.
https://www.google.com/search?q=40+rods+per+us+hogshead+in+metres+per+litre (https://www.google.com/search?q=40+rods+per+us+hogshead+in+metres+per+litre)
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On the subject of cursed units ...
https://www.youtube.com/watch?v=kkfIXUjkYqE (https://www.youtube.com/watch?v=kkfIXUjkYqE)
https://www.youtube.com/watch?v=Zg7xe8MkJHs (https://www.youtube.com/watch?v=Zg7xe8MkJHs)
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... but the Imperial and newer US definition is 1 inch = 2.54 cm (both ratios defined as exact).
Hey, some irritating nitpicking coming up! I'm pretty certain it is 25.4mm, not 2.54cm. Can I have the "Pedant of the Day" award?
That's reserved for someone asking whether X is "hard metric" or "soft metric".
Hard metric ceramic tiles are, say, 150mm, whereas soft metric tiles are 154mm. Convert the latter into Imperial units, and you'll see why.
A lot of tiles in Australia are 180mm x 180mm.
Hold them up against an old 6"x 6" tile & you are battling to see the difference.
I know things are bigger in Australia, but over here 6" is ~153mm.
That doesn't matter on its own, but can be noticeable when aligning a run of tiles with something that is hard metric. A really bad case is creating pattern by intermixing hard and soft metric!
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... but the Imperial and newer US definition is 1 inch = 2.54 cm (both ratios defined as exact).
Hey, some irritating nitpicking coming up! I'm pretty certain it is 25.4mm, not 2.54cm. Can I have the "Pedant of the Day" award?
That's reserved for someone asking whether X is "hard metric" or "soft metric".
Hard metric ceramic tiles are, say, 150mm, whereas soft metric tiles are 154mm. Convert the latter into Imperial units, and you'll see why.
A lot of tiles in Australia are 180mm x 180mm.
Hold them up against an old 6"x 6" tile & you are battling to see the difference.
I know things are bigger in Australia, but over here 6" is ~153mm.
That doesn't matter on its own, but can be noticeable when aligning a run of tiles with something that is hard metric. A really bad case is creating pattern by intermixing hard and soft metric!
Doh!! :-[
Of course you are right!
Somewhere down the line, I had to work with some trim materials (perhaps rectangular tiles) with a standard length of 180mm, & that size was "stuck in my head".
Still no excuse, though, as I have a set of calipers to hand, as well as my ancient HP22s which does inch to cm conversions.
My problem at home is that everything was built using Imperial measures.
Even so, with tiles, the 6" to 150mm tile sizing thing is not a major problem, but the fact that imported tiles from the PRC etc., don't come in the many colour shades which were common in the 1960s & '70s is.
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But I still think that a lot of electronics conventions like these are on account of undue paranoia, like the fear of Xeroxes:
I've seen that as the justification for that silly "xRy" convention (e.g., 6R8K instead of 6.8K), because people are afraid of that little dot disappearing when the schematic gets copied a few times. I suppose that might have happened back in the Stone Age.
Well, it was a well justified fear. unfortunately using 6R8 instead of 6.8 wouldn't have helped.
https://www.dkriesel.com/en/blog/2013/0802_xerox-workcentres_are_switching_written_numbers_when_scanning (https://www.dkriesel.com/en/blog/2013/0802_xerox-workcentres_are_switching_written_numbers_when_scanning)
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But I still think that a lot of electronics conventions like these are on account of undue paranoia, like the fear of Xeroxes:
I've seen that as the justification for that silly "xRy" convention (e.g., 6R8K instead of 6.8K), because people are afraid of that little dot disappearing when the schematic gets copied a few times. I suppose that might have happened back in the Stone Age.
Well, it was a well justified fear. unfortunately using 6R8 instead of 6.8 wouldn't have helped.
https://www.dkriesel.com/en/blog/2013/0802_xerox-workcentres_are_switching_written_numbers_when_scanning (https://www.dkriesel.com/en/blog/2013/0802_xerox-workcentres_are_switching_written_numbers_when_scanning)
Wow... just wow... can't believe that happened. :wtf:
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That was then; this is now; can you still get down and boogie?
Yes Sir, I can Boogie.
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Very good question. I see no logic in it. But I learn the lesson many years ago when I reversed a tantalum thinking the strip was negative. Burnt a hole right through the PCB and set off the fire alarm.
You can think of the stripe as the cathode marking on a diode. Tantalum caps are basically diodes with pathological amounts of Cd, which is why you can jerry-rig a non-polarized electrolytic simply by connecting two tantalums back to back.
The stripe serves as a reminder that it will explode like a diode if you run enough current through it backward.
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But I still think that a lot of electronics conventions like these are on account of undue paranoia, like the fear of Xeroxes:
I've seen that as the justification for that silly "xRy" convention (e.g., 6R8K instead of 6.8K), because people are afraid of that little dot disappearing when the schematic gets copied a few times. I suppose that might have happened back in the Stone Age.
Well, it was a well justified fear. unfortunately using 6R8 instead of 6.8 wouldn't have helped.
https://www.dkriesel.com/en/blog/2013/0802_xerox-workcentres_are_switching_written_numbers_when_scanning (https://www.dkriesel.com/en/blog/2013/0802_xerox-workcentres_are_switching_written_numbers_when_scanning)
Wow. I'd better check if we have any Xerox copiers in the office...
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2) People who thing metric is more accurate.
Seems like a claim made by people who don't know any better?
Accuracy depends on number of decimal places. Units of measurement can be as accurate or inaccurate as you like.
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2) People who thing metric is more accurate.
Accuracy depends on number of decimal places. Units of measurement can be as accurate or inaccurate as you like.
Actually, when discussing the number of decimal places, I think you are talking about precision, rather than accuracy.
I am 21 years, three months, one week, 4 days, 15 hours, 45 minutes and 38.7 seconds old.
That statement is very precise but not very accurate. ;D
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2) People who thing metric is more accurate.
Accuracy depends on number of decimal places. Units of measurement can be as accurate or inaccurate as you like.
Actually, when discussing the number of decimal places, I think you are talking about precision, rather than accuracy.
I am 21 years, three months, one week, 4 days, 15 hours, 45 minutes and 38.7 seconds old.
That statement is very precise but not very accurate. ;D
Yeah yeah, rub it in, you young whipper snapper. :D
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2) People who thing metric is more accurate.
Accuracy depends on number of decimal places. Units of measurement can be as accurate or inaccurate as you like.
Actually, when discussing the number of decimal places, I think you are talking about precision, rather than accuracy.
I am 21 years, three months, one week, 4 days, 15 hours, 45 minutes and 38.7 seconds old.
That statement is very precise but not very accurate. ;D
Yeah yeah, rub it in, you young whipper snapper. :D
His statement could be correct as well as being older than you :)
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Very good question. I see no logic in it. But I learn the lesson many years ago when I reversed a tantalum thinking the strip was negative. Burnt a hole right through the PCB and set off the fire alarm.
You can think of the stripe as the cathode marking on a diode. Tantalum caps are basically diodes with pathological amounts of Cd, which is why you can jerry-rig a non-polarized electrolytic simply by connecting two tantalums back to back.
The stripe serves as a reminder that it will explode like a diode if you run enough current through it backward.
I don't think I have even seen a diode explode / burn like a tantalum capacitor can. If I didn't wear glasses, I would probably be blind due to a tantalum exploding in my face. Because the stubborn designer of the board didn't put the capacitors with the polarity in a uniform direction (against my strong suggestion), the reversed tantalum wasn't noticed during inspection.
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You can think of the stripe as the cathode marking on a diode. Tantalum caps are basically diodes with pathological amounts of Cd, which is why you can jerry-rig a non-polarized electrolytic simply by connecting two tantalums back to back.
The stripe serves as a reminder that it will explode like a diode if you run enough current through it backward.
Now that is some pretty serious mental acrobatics, reminds me of the one who claimed that diodes do not exist but we only have resistors. And of course, we can as well say that diodes are basically tantalum caps with pathologically low amounts of Cd.
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First thing comes to mind, is the classic 'Chivken Head Knobs', but that's not exactly a good answer.
I do think that many portions of the classic residential POWER POLE are becoming obsolete, maybe meaning more telephone service innovation. (Current residential areas there is an upper set of wires, for power delivery, and with phone stuff lower down on each pole.)
I have been noticing heavy squirrel activity, up and down our local pole, and stymied as to what's attracting the small mammal presence ?
Best guess is that they (squirrel) seek to peel soft bark, but they sure are on that pole pretty heavily.
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An interesting argument but I think the issue with considering a tantalum to be the same as a diode, is a diode's capacitance is a function of voltage bias (there is some constant capacitance due to construction, but the majority occurs under bias) whereas a tantalum capacitor would ideally have a very flat capacitance-voltage bias behaviour. There are clearly different processes at play here.
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Neither system is more logical. They are just different. Metric is easier to use.
More accurate? That may have a practical explanation. Designs and drawings using inches commonly use three decimal places or, in other words, thousandths of an inch. Designs and drawings using mm commonly use two decimal places or hundredths of a mm.
A hundredth of a mm translates to 0.000393... inches which is about 2/5ths of a thousandth of an inch.
So using the most common precision that is in common use for each of the two systems of measure, the metric design/drawing will be expressing the dimensions with about 2.5 times the accuracy of the one using inches.
Or at least apparently so at first examination. Yes, the tolerances are always a part of a mechanical design/drawing. And they should ALWAYS be expressed in any drawing. But metric does encourage/suggest the use of greater accuracy in the design process. Drawings of electronic parts where the tolerance is not expressed, 1.23mm is a more precise dimension than 0.048" because in each case a +/- one count in the last digit is assumed. And 0.01mm is less than 0.001" = 0.0254mm.
While this is not the way drawings using each system should be looked at, it is the way that some, dare I say many will look at them.
My two biggest frustrations are:
1) People who claim metric for dimensions is more logical; and
Metric is more logical, for the simple reason that every scale is related by powers of ten, whereas we have 12 inches to a foot, 3 feet to a yard, 1760 yards to a mile, etc. However, there is no advantage in using metric for PCB design because that uses decimal inches (eg 1.27 inches). No feet and yards there.
2) People who thing metric is more accurate.
Really? I've never heard of that before. Does anyone really think that? I wonder if they mean more precise rather than more accurate, but of course that is nonsense, too. You can dial in any level of precision you want with either system.
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I agree. It is an ease f use thing, not accuracy or precision. Most people who use imperial do use fractions and not decimals. I personally am not facile with converting fractions to decimals like a real machinist although I can convert imperial fractions to metric fairly easily in my head.
But why bother, that is what digital measurement tools are for (thank you EEs)
FWIW, US watch factories were using metric at least for 100 years. Interestingly, the panel mounting screws on WWII aircraft clocks were spec'd in imperial. One advantage of metric is that for small parts fewer digits are required on the drawings making them easier to interpret.
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My two biggest frustrations are:
1) People who claim metric for dimensions is more logical; and
Metric is more logical, for the simple reason that every scale is related by powers of ten, whereas we have 12 inches to a foot, 3 feet to a yard, 1760 yards to a mile, etc. However, there is no advantage in using metric for PCB design because that uses decimal inches (eg 1.27 inches). No feet and yards there.
I'm comfortable with both metric and imperial. It doesn't bother me and I can remember the most common conversions.
Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
I prefer the rectangles. I'm terrible at drawing, so my resistors and inductors tend to look similar. It's much easier to just draw a box. I believe the square form comes from carbon composion resistors and the zig-zag from wire wound, but I could be wrong.
The same is true for logic gates. I can understand why some find a diferent shape for each gate is helpful, but a box with a symbol is much easier to draw.
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My two biggest frustrations are:
1) People who claim metric for dimensions is more logical; and
Metric is more logical, for the simple reason that every scale is related by powers of ten, whereas we have 12 inches to a foot, 3 feet to a yard, 1760 yards to a mile, etc. However, there is no advantage in using metric for PCB design because that uses decimal inches (eg 1.27 inches). No feet and yards there.
I'm comfortable with both metric and imperial. It doesn't bother me and I can remember the most common conversions.
Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
I prefer the rectangles. I'm terrible at drawing, so my resistors and inductors tend to look similar. It's much easier to just draw a box. I believe the square form comes from carbon composion resistors and the zig-zag from wire wound, but I could be wrong.
The same is true for logic gates. I can understand why some find a diferent shape for each gate is helpful, but a box with a symbol is much easier to draw.
Before schematic capture software, I had a set of inexpensive plastic drawing templates with good patterns for resistors, capacitors with straight and/or curved plates, inductors, transformers with cores, normal active devices, the usual logic gates, etc. My usual one was small enough to fit in a shirt pocket.
For mechanical drawing, I had other ones with hexagons, circles, ellipses, and some mechanical fasteners.
I keep the templates in a desk drawer, next to my drafting triangles, for emergencies.
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Before schematic capture software, I had a set of inexpensive plastic drawing templates with good patterns for ... the usual logic gates, etc.
I still have mine :)
I also have some Rotring drafting pens, required for a university course and never used thereafter. I wonder if I can flog them on fleabay :)
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Before schematic capture software, I had a set of inexpensive plastic drawing templates with good patterns for ... the usual logic gates, etc.
I still have mine :)
I also have some Rotring drafting pens, required for a university course and never used thereafter. I wonder if I can flog them on fleabay :)
With the US-made templates, I drew on Clearprint drafting vellum with 0.1 inch grid (still available).
In grad school, I took lecture notes with a "00" Koh-I-Noor Rapidograph drafting pen, especially in General Relativity with all the sub- and super-scripts.
Templates are still readily available: https://www.draftingsuppliesdew.com/supplies/drafting-templates-and-drawing-templates?srsltid=AfmBOooIWZ6AR7hTMFgwKGGdx0D4lv7_NUy5Hzup5MDFdS9LY-y7_adL (https://www.draftingsuppliesdew.com/supplies/drafting-templates-and-drawing-templates?srsltid=AfmBOooIWZ6AR7hTMFgwKGGdx0D4lv7_NUy5Hzup5MDFdS9LY-y7_adL)
To quote that vendor: "Drafting templates, also known as drawing stencils, are the secret weapon for precision in technical drawing."
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To quote that vendor: "Drafting templates, also known as drawing stencils, are the secret weapon for precision in technical drawing."
A famous Mandy Rice-Davis response is appropriate: "well, they would say that, wouldn't they"
https://en.wikipedia.org/wiki/Well_he_would%2C_wouldn't_he%3F
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Hey, I still have my IBM flowcharting template:
[attachimg=1]
Does anyone still draw flowcharts? I do occasionally. Very useful for certain situations where it's hard to otherwise visualize a process flow (hence the name).
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Here's another template I have that I've never used. Looks pretty useful if you're dealing with network stuff:
[attachimg=1]
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Hey, I still have my IBM flowcharting template:
(Attachment Link)
Does anyone still draw flowcharts? I do occasionally. Very useful for certain situations where it's hard to otherwise visualize a process flow (hence the name).
I think I still have one of those, and a selection of DoD logic gate stencils. Ah, the bad old days before schematic capture.
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My two biggest frustrations are:
1) People who claim metric for dimensions is more logical; and
Metric is more logical, for the simple reason that every scale is related by powers of ten, whereas we have 12 inches to a foot, 3 feet to a yard, 1760 yards to a mile, etc. However, there is no advantage in using metric for PCB design because that uses decimal inches (eg 1.27 inches). No feet and yards there.
I'm comfortable with both metric and imperial. It doesn't bother me and I can remember the most common conversions.
Here's another one, regarding schematics:
What Euro-genius decided it was a good idea to use blank rectangles for resistors, instead of a proper (zigzag) resistor symbol?
(Attachment Link)
I prefer the rectangles. I'm terrible at drawing, so my resistors and inductors tend to look similar. It's much easier to just draw a box. I believe the square form comes from carbon composion resistors and the zig-zag from wire wound, but I could be wrong.
The same is true for logic gates. I can understand why some find a diferent shape for each gate is helpful, but a box with a symbol is much easier to draw.
Before schematic capture software, I had a set of inexpensive plastic drawing templates with good patterns for resistors, capacitors with straight and/or curved plates, inductors, transformers with cores, normal active devices, the usual logic gates, etc. My usual one was small enough to fit in a shirt pocket.
For mechanical drawing, I had other ones with hexagons, circles, ellipses, and some mechanical fasteners.
I keep the templates in a desk drawer, next to my drafting triangles, for emergencies.
Yes, I've seen those stencils, but haven't used them. Although CAD existed, when I was at college, it still wasn't routinely used on the course and I still often draw schematics by hand.
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Yes, I've seen those stencils, but haven't used them. Although CAD existed, when I was at college, it still wasn't routinely used on the course and I still often draw schematics by hand.
There were 2.5 CAD programs available to me at university.
ICAP and ITAP were local equivalents of Spice small signal and transient analysis.
The 0.5 was the, ahem, word processor some people used to write their final year project report. Too many people wanted to do that so you had to make bookings to use the PDP11 text editor at 3am.
I couldn't be bothered, so I wrote it out longhand, literally cut and pasted paragraphs together, and paid a secretary to type it.
Ah, the bad old days.
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A shoutout here for OrCAD, which got schematic capture onto thousands of desks, and really started to kill off the plastic component template, and mylar sheets. :)
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A shoutout here for OrCAD, which got schematic capture onto thousands of desks, and really started to kill off the plastic component template, and mylar sheets. :)
I really liked the MSDOS version. People who were using Mental Mentor Graphics couldn't believe that you didn't need a mouse.
Never tried the PCB layout side, though; I handed the netlist to a local PCB house, and gave hints about layout.
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Hey, I still have my IBM flowcharting template:
(Attachment Link)
Does anyone still draw flowcharts? I do occasionally. Very useful for certain situations where it's hard to otherwise visualize a process flow (hence the name).
We do at work for documentation of all the important core logic in the firmware (medical industry).
draw.io is a good free tool if you just want to throw a flowchart together yourself.
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Does anyone still draw flowcharts? I do occasionally. Very useful for certain situations where it's hard to otherwise visualize a process flow (hence the name).
I think that depends on what you call a flow chart. The traditional IBM stencil type are pretty rare today, but there are plenty of ways people express the same thing in a different manner. Even by the early 70s huge numbers of people had abandoned flowcharts and moved to something looking more like code, using names like Program Description Language (PDL). Flow charts just take too much space, and as soon as the problem gets a little complex you don't see enough on a single page to properly follow the flow.
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A shoutout here for OrCAD, which got schematic capture onto thousands of desks, and really started to kill off the plastic component template, and mylar sheets. :)
UGH, I started with Orcad. Yes, it was pretty good at simple stuff, but the method of creating a new schematic symbol was REAL dark ages. You entered a string of ASCII * characters and spaces to fill out a rectangle. Shudder!
But, the schematic entry was easy and the PCB layout wasn't bad. I later went to Protel ADV. Schematic and PCB, then Accel and then Protel 99 SE, which I still use.
Jon