5 ms·

It's a pity that our history of low voltage DC connectors has been so poor. The 12V cigarette lighter connector is awful, and yet it became, slowly, the standar

by leoedin 13y ago

It's a pity that our history of low voltage DC connectors has been so poor. The 12V cigarette lighter connector is awful, and yet it became, slowly, the standard for 12V connections. The USB cable is not exactly brilliant either. The article touches on it, but the fact you basically don't know which way it goes in until you attempt to plug it in is awful. Hopefully the manufacturers will have the sense to move towards a slightly more sane connector to use in everything. I think the fear that it has to be backwards compatible is less prevalent now than it used to be (micro USB has completely replaced mini USB in most situations). I'm looking forward to sane relatively high power DC connections everywhere.

voltagex_ 13y ago
>Mr Bhatt, who invented it 20 years ago, is delighted. His next plan is to make the USB cable “flippable”—so that the plug fits the socket whichever way it is inserted (for now it works only one way round). That tiresome flaw is because an original design priority was to make manufacture as cheap as possible: few believed his idea would really catch on.
computerbob 13y ago
What I have never figured out is why they don't color coordinate which side is up or down. Green is up, red is down. It would give a instant visual idea of which way to plug it in. Can't image it would cause the cost to go up.
- lttlrck 13y ago
  Left and right puts a spanner in the works.
- masklinn 13y ago
  > Green is up, red is down. You do realize USB ports can be vertical, and usually are on (USB-enabled) wall outlets, displays and desktop computers right? And that's the simple case of vertical (flipped 90 on the long axis compared to most laptops) with USB-enabled extension cords lying on the floor, you plug straight down.
  - Groxx 13y ago
    So rotate in one direction for vertical for consistency, and color-code the plug for everything that could benefit from it. Matching red/green is far easier than "which side has that mostly-invisible black piece of plastic".
    - masklinn 13y ago
      > So rotate in one direction for vertical for consistency There is no consistency, your USB port may be on the left, right or back of your screen, what's the useful thing to standardize then? And it can jut out from a wall. And on a desktop tower, the USB port can be on the front or the back, and the user may install the machine so it is accessed from the left, the right or either.
      - Groxx 13y ago
        Left/right/back of screen is still the same direction. If it's counter-clockwise from green-up, it's green-left everywhere, including walls. On anything parallel with the floor you're right - so color-code the plug.
- leoedin 13y ago
  In addition to the other issues with this, a standard orientation would require either the PCB the connector's mounted on to be orientated a certain way (potentially having a knockon effect for other design decisions in the device) or require a whole load of different PCB mounted USB connectors. Both would add cost which the manufacturers would much rather do without. In the cheapest devices, the orientation of the USB port would probably be the first thing to go out the window, making the whole exercise redundant. What's needed is a robust connector with an easily visually determined orientation and the sort of power transmission capabilities that the new USB PD standard has.
- lwf 13y ago
  Google managed to colour-coöordinate their Glass charger, so that the wall plug is black-white the same way the cable is, but didn't have a good answer for how to do the device side of the plug. See https://phandroid.s3.amazonaws.com/wp-content/uploads/2013/05/20130509_023847.jpg https://phandroid.s3.amazonaws.com/wp-content/uploads/2013/0...
- VLM 13y ago
  Quite a few years ago when USB was new, a trip to the local hobby store with about $3 cash resulted in a green model builders "paint pen" which is pretty much what it sounds like, a felt tip pen that releases paint. The paint dries out inside the pen after a couple years. I would imagine depending on your local graffiti problem these might be banned even more severely than spray cans, although in a civilized area they should be available? Anyway the next discovery is I charge my phone face down to protect the glass, so I have to plug in upside down. Rightside up and Upside down connectors are commercially available for PCBs because the manufacturers have no idea which side might be up in a finished product. So you've converted the problem from figuring out which side of a cable is up, to memorizing which devices you own that have to be flipped upside down. Of course a dot of the same color paint fixes that although it might look ugly on a phone if done sloppily enough. A greater annoyance is should the USB charger input be on the top, bottom, right or left side of all phones? I think I've seen it all.
- drivers99 13y ago
  Red and green? http://en.wikipedia.org/wiki/Color_blindness http://en.wikipedia.org/wiki/Color_blindness
  - ubernostrum 13y ago
    As a deuteranomalous trichromat (aka, what is popularly called "red-green colorblind"), yes, red and green are fine. I've explained this in more detail before: http://www.reddit.com/r/askscience/comments/1oomt1/how_are_red_green_colorblind_people_able_to/ccu9maj http://www.reddit.com/r/askscience/comments/1oomt1/how_are_r...
    - drivers99 13y ago
      If I understand correctly, based on what you said and comparing it to the rainbows on wikipedia, a trichromat would be fine with red vs green, since they are distinguishable, but nearby colors to those (red -> orange, green -> blue) look more similar (different shades of the same color). And looking into it some more, a dichromat would be fine as well because the two colors would be distinguishable because green would be essentially dark and red would be light (i.e. "the dark side goes up" in the USB example).
quarterto 13y ago
Ninety-nine times out of a hundred, the side with the USB logo faces up. Less useful when you can't see where you're plugging it, or the socket is at an angle, but it helps.
- UnoriginalGuy 13y ago
  Or if some manufacturers (Apple) print a USB logo on one side and an Apple logo in the same colour and size on the other. http://media.idownloadblog.com/wp-content/uploads/2012/01/usb-cable.jpg http://media.idownloadblog.com/wp-content/uploads/2012/01/us...
  - quarterto 13y ago
    It's still usually the USB logo in that case. The one exception I've noticed is the Cyborg R.A.T. 7 mouse, which goes in with the Cyborg logo up.
    - UnoriginalGuy 13y ago
      I'm not sure I follow. It has the USB logo on one side, and the Apple logo on the other side in the same colour and size. Which means if you aren't paying attention you'll over try to put it in upside down (because the logos look so similar).
      - quarterto 13y ago
        ...then pay attention? The Apple and USB logos look nothing like each other, even at a glance.
      - Dylan16807 13y ago
        If you're not paying attention you won't notice the logo at all.
  - arrrg 13y ago
    Apple hasn’t done that for a long, long time.
VLM 13y ago
Be sure to talk to the ham radio guys and RC car guys first, who have a couple decades experience with almost uncountable number of DC power "standards", or you'll just poorly reimplement something they already figured out back in 1970 or whatever. The Anderson Powerpole seems a rather effective and cheap way to shove a couple hundred watts of DC around. Of course there must be millions of existing connectors all operating at 12 volts so applying it to a 5V standard will be problematic at best. I have them all over my house given my electronic interests. Do NOT listen to people who complain about them, much like the legendary PL-259 connector or soldering SMD device by hand, 99.99% of the population just does it no problem without drama but the 0.01% who can't be bothered to learn how, make sure to very loudly tell everyone about how it never works, etc. Its tiresome but traditional. The molex family seems most effective at demonstrating the flammability of overheated nylon, at least at power levels over a hundred or so watts. The ancient Cinch plugs worked sorta well, although they're a bit large and fiddly. Coaxial DC connectors are something of a standard although few can handle a hundred watts, at least at low DC voltage. A miniaturized version of the standard used for intelligent electric vehicle charging would be interesting. There's probably a patent preventing innovation, but maybe in a few decades when existing patents run out thus permitting innovation to start again...
- adestefan 13y ago
  The Powerpole "standard" has also been completely disregarded. The housing color is suppose to represent the voltage, but now it's been co-opted to the point where you see red and black as + and - 13.8v.
  - VLM 13y ago
    That's the nice thing about standards, there are so many conflicting ones to choose from. And you are correct before hams started using powerpoles in wholesale lots, the mfgr had a semi-elaborate scheme for full scale railroad wiring where the color had a meaning WRT voltage which the hams disregarded and decided to use red/black. That's in itself is a lesson optimistic power connector designers need to learn about the past, if you "borrow" something currently used for marine power, or solar panel wiring, or forklift battery chargers, and try to do something totally different, expect some conflicts even if the new app dwarfs the old one by a couple orders of magnitude. Yes, on a railroad locomotive engine I wouldn't randomly plug red/black ham radio powerpoles into the first railroad engine red/black that you see, its not going to be what you expected. Almost everywhere else, it will work.

by leoedin 13y ago

voltagex_ 13y ago

>Mr Bhatt, who invented it 20 years ago, is delighted. His next plan is to make the USB cable “flippable”—so that the plug fits the socket whichever way it is inserted (for now it works only one way round). That tiresome flaw is because an original design priority was to make manufacture as cheap as possible: few believed his idea would really catch on.

computerbob 13y ago

What I have never figured out is why they don't color coordinate which side is up or down. Green is up, red is down. It would give a instant visual idea of which way to plug it in. Can't image it would cause the cost to go up.

lttlrck 13y ago
Left and right puts a spanner in the works.
masklinn 13y ago
> Green is up, red is down. You do realize USB ports can be vertical, and usually are on (USB-enabled) wall outlets, displays and desktop computers right? And that's the simple case of vertical (flipped 90 on the long axis compared to most laptops) with USB-enabled extension cords lying on the floor, you plug straight down.
- Groxx 13y ago
  So rotate in one direction for vertical for consistency, and color-code the plug for everything that could benefit from it. Matching red/green is far easier than "which side has that mostly-invisible black piece of plastic".
  - masklinn 13y ago
    > So rotate in one direction for vertical for consistency There is no consistency, your USB port may be on the left, right or back of your screen, what's the useful thing to standardize then? And it can jut out from a wall. And on a desktop tower, the USB port can be on the front or the back, and the user may install the machine so it is accessed from the left, the right or either.
    - Groxx 13y ago
      Left/right/back of screen is still the same direction. If it's counter-clockwise from green-up, it's green-left everywhere, including walls. On anything parallel with the floor you're right - so color-code the plug.
leoedin 13y ago
In addition to the other issues with this, a standard orientation would require either the PCB the connector's mounted on to be orientated a certain way (potentially having a knockon effect for other design decisions in the device) or require a whole load of different PCB mounted USB connectors. Both would add cost which the manufacturers would much rather do without. In the cheapest devices, the orientation of the USB port would probably be the first thing to go out the window, making the whole exercise redundant. What's needed is a robust connector with an easily visually determined orientation and the sort of power transmission capabilities that the new USB PD standard has.
lwf 13y ago
Google managed to colour-coöordinate their Glass charger, so that the wall plug is black-white the same way the cable is, but didn't have a good answer for how to do the device side of the plug. See https://phandroid.s3.amazonaws.com/wp-content/uploads/2013/05/20130509_023847.jpg https://phandroid.s3.amazonaws.com/wp-content/uploads/2013/0...
VLM 13y ago
Quite a few years ago when USB was new, a trip to the local hobby store with about $3 cash resulted in a green model builders "paint pen" which is pretty much what it sounds like, a felt tip pen that releases paint. The paint dries out inside the pen after a couple years. I would imagine depending on your local graffiti problem these might be banned even more severely than spray cans, although in a civilized area they should be available? Anyway the next discovery is I charge my phone face down to protect the glass, so I have to plug in upside down. Rightside up and Upside down connectors are commercially available for PCBs because the manufacturers have no idea which side might be up in a finished product. So you've converted the problem from figuring out which side of a cable is up, to memorizing which devices you own that have to be flipped upside down. Of course a dot of the same color paint fixes that although it might look ugly on a phone if done sloppily enough. A greater annoyance is should the USB charger input be on the top, bottom, right or left side of all phones? I think I've seen it all.
drivers99 13y ago
Red and green? http://en.wikipedia.org/wiki/Color_blindness http://en.wikipedia.org/wiki/Color_blindness
- ubernostrum 13y ago
  As a deuteranomalous trichromat (aka, what is popularly called "red-green colorblind"), yes, red and green are fine. I've explained this in more detail before: http://www.reddit.com/r/askscience/comments/1oomt1/how_are_red_green_colorblind_people_able_to/ccu9maj http://www.reddit.com/r/askscience/comments/1oomt1/how_are_r...
  - drivers99 13y ago
    If I understand correctly, based on what you said and comparing it to the rainbows on wikipedia, a trichromat would be fine with red vs green, since they are distinguishable, but nearby colors to those (red -> orange, green -> blue) look more similar (different shades of the same color). And looking into it some more, a dichromat would be fine as well because the two colors would be distinguishable because green would be essentially dark and red would be light (i.e. "the dark side goes up" in the USB example).

quarterto 13y ago

Ninety-nine times out of a hundred, the side with the USB logo faces up. Less useful when you can't see where you're plugging it, or the socket is at an angle, but it helps.

UnoriginalGuy 13y ago
Or if some manufacturers (Apple) print a USB logo on one side and an Apple logo in the same colour and size on the other. http://media.idownloadblog.com/wp-content/uploads/2012/01/usb-cable.jpg http://media.idownloadblog.com/wp-content/uploads/2012/01/us...
- quarterto 13y ago
  It's still usually the USB logo in that case. The one exception I've noticed is the Cyborg R.A.T. 7 mouse, which goes in with the Cyborg logo up.
  - UnoriginalGuy 13y ago
    I'm not sure I follow. It has the USB logo on one side, and the Apple logo on the other side in the same colour and size. Which means if you aren't paying attention you'll over try to put it in upside down (because the logos look so similar).
    - quarterto 13y ago
      ...then pay attention? The Apple and USB logos look nothing like each other, even at a glance.
    - Dylan16807 13y ago
      If you're not paying attention you won't notice the logo at all.
- arrrg 13y ago
  Apple hasn’t done that for a long, long time.

VLM 13y ago

Be sure to talk to the ham radio guys and RC car guys first, who have a couple decades experience with almost uncountable number of DC power "standards", or you'll just poorly reimplement something they already figured out back in 1970 or whatever. The Anderson Powerpole seems a rather effective and cheap way to shove a couple hundred watts of DC around. Of course there must be millions of existing connectors all operating at 12 volts so applying it to a 5V standard will be problematic at best. I have them all over my house given my electronic interests. Do NOT listen to people who complain about them, much like the legendary PL-259 connector or soldering SMD device by hand, 99.99% of the population just does it no problem without drama but the 0.01% who can't be bothered to learn how, make sure to very loudly tell everyone about how it never works, etc. Its tiresome but traditional. The molex family seems most effective at demonstrating the flammability of overheated nylon, at least at power levels over a hundred or so watts. The ancient Cinch plugs worked sorta well, although they're a bit large and fiddly. Coaxial DC connectors are something of a standard although few can handle a hundred watts, at least at low DC voltage. A miniaturized version of the standard used for intelligent electric vehicle charging would be interesting. There's probably a patent preventing innovation, but maybe in a few decades when existing patents run out thus permitting innovation to start again...

adestefan 13y ago
The Powerpole "standard" has also been completely disregarded. The housing color is suppose to represent the voltage, but now it's been co-opted to the point where you see red and black as + and - 13.8v.
- VLM 13y ago
  That's the nice thing about standards, there are so many conflicting ones to choose from. And you are correct before hams started using powerpoles in wholesale lots, the mfgr had a semi-elaborate scheme for full scale railroad wiring where the color had a meaning WRT voltage which the hams disregarded and decided to use red/black. That's in itself is a lesson optimistic power connector designers need to learn about the past, if you "borrow" something currently used for marine power, or solar panel wiring, or forklift battery chargers, and try to do something totally different, expect some conflicts even if the new app dwarfs the old one by a couple orders of magnitude. Yes, on a railroad locomotive engine I wouldn't randomly plug red/black ham radio powerpoles into the first railroad engine red/black that you see, its not going to be what you expected. Almost everywhere else, it will work.