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+--- Thread: Why two power ports on a budget laptop?? (/showthread.php?tid=10930)
RE: Why two power ports on a budget laptop?? - jiyong - 08-10-2020
(08-10-2020, 01:47 AM)KC9UDX Wrote: "in the worst case scenario this USB or that USB"
In the worst case scenario, I cut the plug off and stick the wires into the barrel jack. Do that with a USB socket
When you are not quoting people, don't use quotes.
Now you are just being childish.
Discuss like an adult, not like a little child that didn't get a cookie.
And good luck with shorting the wires.
RE: Why two power ports on a budget laptop?? - KC9UDX - 08-10-2020
(08-10-2020, 03:32 AM)jiyong Wrote: When you are not quoting people, don't use quotes.
Now you are just being childish.
Discuss like an adult, not like a little child that didn't get a cookie.
And good luck with shorting the wires.
But who is being childish? I was quoting, or rather paraphrasing. It should have been obvious.
I have done this with barrel jacks, when it was necessary. This was in the days before USB. It can be done. It can't be done with USB. Well, it would be much more difficult.
Because you don't believe me, or you disagree with me does not make me childish.
RE: Why two power ports on a budget laptop?? - dsimic - 08-10-2020
(08-10-2020, 03:59 AM)KC9UDX Wrote: I have done this with barrel jacks, when it was necessary. This was in the days before USB. It can be done. It can't be done with USB. Well, it would be much more difficult.
I do not intend to take sides in this argument, but you could rather easily wedge two bare wires into the outer pin positions of a female USB Type-A connector, which provide power. However, it's a whole different matter why would you want to do something like that.
RE: Why two power ports on a budget laptop?? - KC9UDX - 08-10-2020
(08-10-2020, 04:08 AM)dsimic Wrote:Possibly. But what charges with a female USB-A?(08-10-2020, 03:59 AM)KC9UDX Wrote: I have done this with barrel jacks, when it was necessary. This was in the days before USB. It can be done. It can't be done with USB. Well, it would be much more difficult.
I do not intend to take sides in this argument, but you could rather easily wedge two bare wires into the outer pin positions of a female USB Type-A connector, which provide power. However, it's a whole different matter why would you want to do something like that.
The whole point is that with a barrel jack, you can charge it with any power supply that supplies correct voltage, in a pinch. At one time, annoying manufacturers would use an odd-sized barrel plug so that you'd have to buy their wall wart. When you can't get one, and you must power the device, you do what you have to do. It's the worst case scenario. At least, it's the least possible workable situation. Obviously it could get much worse such as having no source of electricity, but you just don't have a chance then.
It was said earlier that a USB-C is more useful in the worst case scenario, and I disagree, with reason.
RE: Why two power ports on a budget laptop?? - dsimic - 08-10-2020
(08-10-2020, 05:31 AM)KC9UDX Wrote: Possibly. But what charges with a female USB-A?
The whole point is that with a barrel jack, you can charge it with any power supply that supplies correct voltage, in a pinch. At one time, annoying manufacturers would use an odd-sized barrel plug so that you'd have to buy their wall wart. When you can't get one, and you must power the device, you do what you have to do. It's the worst case scenario. At least, it's the least possible workable situation. Obviously it could get much worse such as having no source of electricity, but you just don't have a chance then.
It was said earlier that a USB-C is more useful in the worst case scenario, and I disagree, with reason.
There are various chargers with female USB Type-A ports, for example. Furthermore, any USB Type-A host port on a computer belongs to that category.
Sure, barrel jacks are "dumb", which is good in this case, and can accept pretty much anything with correct voltage and enough current. In that case, the worst-case scenario is that one has no original "barrel-style" charger, but has soldering skills and good access to the required tools and parts.
On the other hand, Type-C chargers are quite smart and a whole lot of negotiation is required between the charger and the charged device. As we know, there are different "languages" spoken by the chargers and the devices, which many times ends up in no understanding. In that case, the worst-case scenario is that one has no original Type-C charger, but has a number of other Type-C chargers lying around.
I guess it's all up to one's perception of the worse-case scenario.
RE: Why two power ports on a budget laptop?? - Arwen - 08-10-2020
I think more obvious answers could be;
* They thought 5v @3amp would be enough
* Pinebook Pro is their first USB-C charging device, so they wanted a backup plan for power in case it did not work well, (or at all), see above.
RE: Why two power ports on a budget laptop?? - dsimic - 08-10-2020
(08-10-2020, 10:39 AM)Arwen Wrote: I think more obvious answers could be;
* They thought 5v @3amp would be enough
* Pinebook Pro is their first USB-C charging device, so they wanted a backup plan for power in case it did not work well, (or at all), see above.
Unfortunately, the PBP's Type-C charging option doesn't seem to have been directed toward a backup plan. According to the PBP circuitry, the maximum current allowed to be taken from the Type-C port is even lower than the maximum current allowed to be taken from the barrel connector. More precisely, it's 2.52 A vs. 2.98 A, both at 5 V of course.
RE: Why two power ports on a budget laptop?? - moonwalkers - 08-10-2020
IMHO from purely technical perspective the best scenario would be:
1. run laptop off the AC adapter when it is connected, using excess power to charge the battery (or supplementing lacking power using battery, if AC adapter is not powerful enough) similar to other laptops, instead of running off battery only and using AC only to charge the battery, resulting in the 3A limit on the battery charging lead also imposing how much the machine can draw from AC adapter.
2. Support USB PD specification beyond 5V/3A - this would make USB-C charging useful enough to hold its own against barrel plug (unless said support is already there but is limited by the point #1).
3. Keep both ports - this adds versatility, making PBP into more of an "ultimate road warrior" machine - but allow people not to purchase the barrel plug AC adapter, especially if it's only 3A instead of at least 4.5A.
I imagine though this may make it more expensive, especially the USB PD support. I would be willing to pay the extra - I'm probably paying more in shipping costs anyway - but I'm not going to speak for everyone else.
P.S.: KC9UDX's quip about sticking wires into power jack reminded me when one time my 170W power brick for ThinkPad W510 failed and all I had to replace it was a 90W PSU intended for ThinkPad T6x series, with which my W510 throttled to a crawl. I ended up putting a piece of sticky tape over the contacts on the power connector on its motherboard, then over that tape inserting a staple to short-out two signal wires that are used to communicate the PSU power output and putting another piece of sticky type as a makeshift insulator. That fooled the machine into thinking it got a much more powerful PSU connected to it and allowed me to get the work done much faster. The 90W PSU did get hot, but since the work I was doing didn't need GPU the power draw was still within its limits. The reaction on the customer's faces was priceless when they saw me pulling out my multitool, popping the keyboard open and doing the whole hack in about 5 minutes.
RE: Why two power ports on a budget laptop?? - dsimic - 08-10-2020
(08-10-2020, 11:19 AM)moonwalkers Wrote: IMHO from purely technical perspective the best scenario would be:
1. run laptop off the AC adapter when it is connected, using excess power to charge the battery (or supplementing lacking power using battery, if AC adapter is not powerful enough) similar to other laptops, instead of running off battery only and using AC only to charge the battery, resulting in the 3A limit on the battery charging lead also imposing how much the machine can draw from AC adapter.
2. Support USB PD specification beyond 5V/3A - this would make USB-C charging useful enough to hold its own against barrel plug (unless said support is already there but is limited by the point #1).
3. Keep both ports - this adds versatility, making PBP into more of an "ultimate road warrior" machine - but allow people not to purchase the barrel plug AC adapter, especially if it's only 3A instead of at least 4.5A.
I imagine though this may make it more expensive, especially the USB PD support. I would be willing to pay the extra - I'm probably paying more in shipping costs anyway - but I'm not going to speak for everyone else.
Totally agreed. However, the only trouble with the first requirement would be that the simple barrel connector pretty much couldn't be used any more.
See, a "barrel-style" power adapter couldn't be "dumb" any more, it would instead have to be able to communicate its wattage with the laptop. By the way, the battery inside the PBP actually isn't limited to 3 A during charging, it can take 5 A easily.
RE: Why two power ports on a budget laptop?? - dieselnutjob - 08-10-2020
I have a couple of early Sony ZX phones in our house which have been charged every day for the last four years.
One of them has just about become unusable as even a new cable is too loose in the socket.
The other isn't far behind.
So I think that I am entitled to believe that the usb-C ports on these phones are not as tough as the barrel sockets that still work on some of my truly ancient laptops (Compaq NC610 with a real parallel port anyone?, or IBM Thinkpad T23? or how about a Toshiba Tecra 800 that still works as a Bosch KTS diagnostic computer, last update in 2007).