Power supply standards.

[farkas]

Charger and power supply standards.

I have a whole boxful of little black bricks in my garage that were used for single device. The only thing in common is the plug that connects to the wall socket. Sizes and shapes vary, most are for 12V DC at various amperage.
The ends that plug into the device are dependent on the manufacturer. Some with the required specs won't fit into another device with the same specs. Then there is the fine print in the warranty if you use something other than the manufacturer provided power source the warranty is void. As an example, 12V DC @ 3A is the same thing wherever you are in the universe. Why can't there be a standard for power supplies that will meet the demands of most laptops and peripherals. If a piece of equipment requires more power than a standard PS can provide than the manufacturer should make provisions for it either by software, on screen, warning and shutdown or a non standard connection.
There are many standards in the electronic industry, USB, HDMI, etc.
It would be nice if there was a universal plug in phone charger standard. No matter what brand. The same with wireless chargers.

[antikythera]

There is now, USB-C. It can be used to charge laptops, tablets and smartphones which is why it's becoming the standard connection type slowly for all new devices and some Manufacturers are just including a USB-C cable in the box instead of a wired charger.

[GS3]

I have whole crates full of wall warts of all sorts with the hope that one day I will find a use for them and occasionally I do but mostly they are useless. The older type of unregulated transformer-rectifier-capacitor have very wide voltage swings depending on load and you have to match them to the load. On the other hand they are bulletproof when compared to the newer switching PSU. I still manage to find use for one of the older ones every now and then but it is mostly a waste of time when new ones are so inexpensive.

The old ones are good to make simple battery chargers. A battery holder, a resistor and a wall-wart and you have a battery charger. When I had cameras and other devices that used rechargeable cells I used to have these. Now it seems I have no need to recharge batteries any more, just the phone.

[Lady Fitzgerald]

I also have a boat load of wall warts and a few bricks (PSUs that have a cable on both ends) that survived the devices they were originally designed for. Occasionally, I'm able to use one as a direct replacement for one that has gone belly up. Other times, I've cut the output plug off a wall wart that has croaked and splice it onto the output lead of one of the salvaged wall warts that has the same voltage and current rating as the recently deceased one. I also save the output leads/plugs of dead wall warts for possible use with another one.

I repurposed one 19v brick (I don't even remember what it was originally for) for testing computer PSU cables I've made for possible arcing a DVOM can't detect at lower voltages. This insures voltages up to 12v won't arc over from one lead to another due an insulation failure due to the heat needed to make and sleeve some cables.

I agree that wall warts and bricks should be designed to put out a few regulated, standard voltages, such as 12v and 5v, and have standardized connectors on them. With the possible (albeit unlikely) exception of ones that use USB C connectors, I doubt we will ever see it happen.

[Portreve]

I, too, have had a lot of bricks and wall warts — I love that term! — over the years. I've gotten rid of almost all of them, with the exception of those for the stuff I'm still using, and a couple general purpose ones.

USB-C is, I think, in time going to be a real godsend because the OP and others here are right: we don't need to make perfectly good, basic electrical hardware redundant needlessly.

[GS3]

It would be nice if there was a universal plug in phone charger standard.

There pretty much is and it is USB. China was the first country to require phones to use 5V and USB connector around 2006~2007 and then the EU and others followed suit.

It is not so difficult to require phones to adopt a single 5V standard because the power requirements are relatively low but once you get past 20 or 25W then it is not so easy. You would need to establish different standards for different power needs because you can't just mandate power supplies that are much larger than the device needs just so they can later be used with other devices. You do not want to oversize power supplies so they can be used with other devices because you are wasting money and resources.

Some laptops could use different powered bricks and they had a third communication wire where the laptop and the power supply would negotiate the power requirements. This might have some advantage but the third wire and the connector pin were easy to break and then it was worse than nothing.

Complex problems do not have simple, easy solutions.

[Lady Fitzgerald]

...we don't need to make perfectly good, basic electrical hardware redundant needlessly.

We don't but many manufacturers think they need to have their own standards, especially proprietary ones, to either force us to buy new hardware or to buy only their hardware (mutter, mutter, mumble, mumble). They won't want to make regulated PSUs because it would cost them more.

[Portreve]

Personally, I think there needs to be an industry consensus, most likely driven by major governmental action, and then backed up by corresponding regulation. I know this sort of thing, in terms of public approval, will break largely — though not exclusively — along political party lines here in the U.S., but something needs to give. And continuing to shove more crap into landfills which doesn't need to be there is simply not the answer, going forward.

I know there's not even a snowball's chance in Hell of this happening (or at least being initiated) here in the U.S., but this is absolutely something the EU could do, getting various Asian partner nations to go along. If the U.S. won't lead, it's about time the EU steps up and acts like the adult in the room.

[RollyShed]

There is now, USB-C. It can be used to charge laptops, tablets and smartphones which is why it's becoming the standard connection type slowly for all new devices and some Manufacturers are just including a USB-C cable in the box instead of a wired charger.

How? most? all? laptops want 18 - 19.5 volts to charge their 6 - 12 volt batteries.
As for power plugs into laptops there are at least half a dozen different sizes and shapes.

Even something "standard" such as video output there are half a dozen different connectors, VGA, DVI-I, DVI-D, HDMI, Displayport, etc. etc. plus miniature versions of these.

[lsemmens]

You are not alone, I do tend to re-purpose those old PSUs as I have a need. At least, they have a label on them that tells you what the Voltage and Current output is on the device. A pair of side cutters, and a soldering iron, and I can easily solder an appropriate connector to the output lead.

[GS3]

You are not alone, I do tend to re-purpose those old PSUs as I have a need. At least, they have a label on them that tells you what the Voltage and Current output is on the device. A pair of side cutters, and a soldering iron, and I can easily solder an appropriate connector to the output lead.

You need to be careful with the old unregulated power supplies because the nominal voltage has little to do with actual voltage output and they have to have enough load to bring the voltage down. A nominal 12 V unit can easily reach 20 V with no load and can damage some electronics. A nominally 12V - 1A unit can easily be found to be putting out 16 V at a lesser amperage.

I often have a little note taped to an unregulated PSU with a table showing output voltage and ripple at different output currents.

And one thing I do is measure the current consumption of devices. Pretty much every router, switch, etc. I use will have a note taped to the underside showing voltage and current needed so I can more easily replace the PSU.

[lsemmens]

You are not alone, I do tend to re-purpose those old PSUs as I have a need. At least, they have a label on them that tells you what the Voltage and Current output is on the device. A pair of side cutters, and a soldering iron, and I can easily solder an appropriate connector to the output lead.

You need to be careful with the old unregulated power supplies because the nominal voltage has little to do with actual voltage output and they have to have enough load to bring the voltage down. A nominal 12 V unit can easily reach 20 V with no load and can damage some electronics. A nominally 12V - 1A unit can easily be found to be putting out 16 V at a lesser amperage.

I often have a little note taped to an unregulated PSU with a table showing output voltage and ripple at different output currents.

And one thing I do is measure the current consumption of devices. Pretty much every router, switch, etc. I use will have a note taped to the underside showing voltage and current needed so I can more easily replace the PSU.

Well said. I usually test a PSU with a meter before re-purposing it. But your comment about regulation should be taken to heart.

[RollyShed]

If it is heavy it will have a transformer, rectifier and smoothing capacitor, plus a nominal output voltage.

If it is light it should have a switch-mode supply which means regulated and fairly close to the nominated output voltage.

I put masking tape labels on them so the output is readable from a distance - distance from shelf to eye.

[antikythera]

How? most? all? laptops want 18 - 19.5 volts to charge their 6 - 12 volt batteries.
As for power plugs into laptops there are at least half a dozen different sizes and shapes.

Even something "standard" such as video output there are half a dozen different connectors, VGA, DVI-I, DVI-D, HDMI, Displayport, etc. etc. plus miniature versions of these.

That is the whole point of standardising it with USB-C whichis happening slowly.

USB-C can handle that variation in voltage and power demand, I have a 45W qualcomm fast charger for my smartphone and tablet which automatically switches to the right requirement of power the connected device can handle safely and has overcharge and thermal limiting safety measures. It would certainly charge or even power a laptop which draws only 45W. There are some USB-C chargers rated for 60W too.

Also, while the topic is about power supply, not video outputs I too have a drawer full of different video cables

[GS3]

That is the whole point of standardising it with USB-C whichis happening slowly.

USB-C can handle that variation in voltage and power demand, I have a 45W qualcomm fast charger for my smartphone and tablet which automatically switches to the right requirement of power the connected device can handle safely and has overcharge and thermal limiting safety measures. It would certainly charge or even power a laptop which draws only 45W. There are some USB-C chargers rated for 60W too.

Yes, but all this convenience comes at a cost. A simple, basic PSU fills the need at the lowest cost. Now you start adding circuitry, connector pins, etc. and that adds cost, complexity, failure possibilities, etc. All these things have to be weighed very carefully.

Many devices are going to require several voltages and will need a special PSU anyway or internal voltage conversion.

Another issue is whether devices have internal or external PSU. Switching PSU are one of the most prone to failure parts of devices, especially the capacitors. External PSU means you can easily detect and replace the faulty PSU but I find it a pain to have power bricks in the way. Internal PSU means a brick is no longer in the way but repair becomes more complicated and the device is probably going to be discarded when it fails.

I recently found a nice monitor out on the sidewalk. I took it home and the problem was a bad (internal) PSU. Bad diodes due to a bad design. I replaced the diodes with sturdier diodes and all is well.

At least I could repair the PSU. I hate it when I find devices with external PSU and the PSU is missing. I have a couple HP Photosmart printer-scanner-cardreader combos which require two voltages, something like 36 and 16 volts, and they are missing the PSU. People dump them when the printer stops working but the scanner and memory card reader still work fine. Why keep a PSU they cannot use?

One reason manufacturers like to use external PSUs is that they only need to certify the PSU as compliant with insulation and safety regulations.