From Newsgroup: sci.electronics.repair

I probably don't need a universal auto power supply, but otoh, if I'd
bought one for the last laptop, I wouldn't to spend 30 or so dollars for another one now.

Some of them have 3 wires connecting the tips, one to tell the power
supply what voltage to provide, I assume, but others have only 2. How
can that be satisfactory.

This one, for example. https://www.amazon.com/HKY-Universal-Notebook-Computer-Smartphone/dp/B0BZGSMLMP/ref=sr_1_1_sspa
See the first picture. But it's $44, one of the most expensive. How
could it not work right?



https://www.amazon.com/Belker-Universal-Adapter-Charger-Toshiba/dp/B08LKXDBX3/ref=sr_1_1_sspa
Smaller than most. Are they just trying to trade off the name Belkin?

At first I thought it had to be good because it was Belker, but when
writing this post, I remembered that it's Belkin that has a reputation,
not Belker. !!

2) Some have 50W, 65W or even 100W. What could need 100W? I
currently have a Dell Latituded 5510 (not the other Dell 5510). Surely
65 w is enough or even 50. ????
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From Newsgroup: sci.electronics.repair

On Sun, 3/30/2025 11:55 AM, micky wrote:

I probably don't need a universal auto power supply, but otoh, if I'd
bought one for the last laptop, I wouldn't to spend 30 or so dollars for another one now.

Some of them have 3 wires connecting the tips, one to tell the power
supply what voltage to provide, I assume, but others have only 2. How
can that be satisfactory.

This one, for example. https://www.amazon.com/HKY-Universal-Notebook-Computer-Smartphone/dp/B0BZGSMLMP/ref=sr_1_1_sspa
See the first picture. But it's $44, one of the most expensive. How
could it not work right?

https://www.amazon.com/Belker-Universal-Adapter-Charger-Toshiba/dp/B08LKXDBX3/ref=sr_1_1_sspa
Smaller than most. Are they just trying to trade off the name Belkin?

At first I thought it had to be good because it was Belker, but when
writing this post, I remembered that it's Belkin that has a reputation,
not Belker. !!

2) Some have 50W, 65W or even 100W. What could need 100W? I
currently have a Dell Latituded 5510 (not the other Dell 5510). Surely
65 w is enough or even 50. ????

Car 12VDC ----------- DC-DC converter ----- USBPD ---+---- USBC output (uses USBPD protocol)
Lighter Socket? | (for USB port charge)
|
+--- dumb charging, fixed voltage,
barrel adapter

I don't know if the adapter works in those rental cars
with the plastic cover.

The USB PD output option is likely safe.
The charging speed will be a function of whether
the laptop even has USB PD protocol. If the adapter were to output
5V @ 1A for example, the laptop will use a boost converter
inside, to charge a 14.4V battery pack. If a higher USB PD
voltage can be negotiated, it might take only
a buck (down) converter inside the laptop, to charge the battery.

For legacy laptops, this kit proposes to charge
via a barrel jack. Does it actually output the correct
voltage ? I would be concerned about that. There was
evidence previously, that the voltage uncertainty on barrel
charging was fairly small (even though from an engineering
perspective, it's not necessary for that voltage to be
all that tight). I would still be a bit nervous about
barrel charging, unless the product had a way of selecting
18.5V, 19V, 20V, or whatever the listed spec for the
laptop is. I do not want to recommend solutions to people,
that only burn out the charge management in a laptop a month
later. That's what happened in at least one case here.
That was the anecdotal evidence, that a mismatch on
barrel voltage, put something under stress. Someone visiting
had a shit eating grin on their face, over the "universal"
product they bought. A month later they wrote back to say
the laptop would no longer charge, with anything.

If you have a USB PD laptop, go for it. Otherwise, do not.

H11: 16V 4A 6.5*4.5mm 19.5v 3.3a 4.7a 6.5*4.4mm
So the barrel adapter H11 works with both a 16V laptop
and a 19.5V laptop ??? Most of the other barrel tips are playing
the close enough game, when they might not be close enough.
It could just be using a fixed 19V output when the USB PD
protocol is not detected. The advert is pleasantly unclear
on the matter.

Paul
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From Newsgroup: sci.electronics.repair

In sci.electronics.repair, on Sun, 30 Mar 2025 13:01:25 -0400, Paul <nospam@needed.invalid> wrote:

On Sun, 3/30/2025 11:55 AM, micky wrote:

I probably don't need a universal auto power supply, but otoh, if I'd
bought one for the last laptop, I wouldn't to spend 30 or so dollars for
another one now.

Some of them have 3 wires connecting the tips, one to tell the power
supply what voltage to provide, I assume, but others have only 2. How
can that be satisfactory.

This one, for example.
https://www.amazon.com/HKY-Universal-Notebook-Computer-Smartphone/dp/B0BZGSMLMP/ref=sr_1_1_sspa
See the first picture. But it's $44, one of the most expensive. How
could it not work right?



https://www.amazon.com/Belker-Universal-Adapter-Charger-Toshiba/dp/B08LKXDBX3/ref=sr_1_1_sspa
Smaller than most. Are they just trying to trade off the name Belkin?

At first I thought it had to be good because it was Belker, but when
writing this post, I remembered that it's Belkin that has a reputation,
not Belker. !!

2) Some have 50W, 65W or even 100W. What could need 100W? I
currently have a Dell Latituded 5510 (not the other Dell 5510). Surely
65 w is enough or even 50. ????

Car 12VDC ----------- DC-DC converter ----- USBPD ---+---- USBC output (uses USBPD protocol)
Lighter Socket? | (for USB port charge)
|
+--- dumb charging, fixed voltage,
barrel adapter

I don't know if the adapter works in those rental cars
with the plastic cover.

I only wanted that to charge my phone. Had a hotel and used the
computer there.

But when I do foreign travel, even if I have rented a room, it can be
too far to drive back at night just to return the next morning, so i
often sleep in the car, and use the laptop before sleeping and in the
morning. (ne time I used while driving it to find a particular stream
in a "park" and I got interested in having GPS for the laptop, but none
of them had iirc very good reviews and now I can't remmeber why the
phone wasn't good enough anyhow.)

But I will make sure any rental car in the future has a cigarette
lighter. or power port and young'ns call them.

The USB PD output option is likely safe.
The charging speed will be a function of whether
the laptop even has USB PD protocol. If the adapter were to output
5V @ 1A for example, the laptop will use a boost converter
inside, to charge a 14.4V battery pack. If a higher USB PD
voltage can be negotiated, it might take only
a buck (down) converter inside the laptop, to charge the battery.

For legacy laptops, this kit proposes to charge
via a barrel jack. Does it actually output the correct
voltage ? I would be concerned about that. There was
evidence previously, that the voltage uncertainty on barrel
charging was fairly small (even though from an engineering
perspective, it's not necessary for that voltage to be
all that tight). I would still be a bit nervous about
barrel charging, unless the product had a way of selecting
18.5V, 19V, 20V, or whatever the listed spec for the

The first one I listed above had none.

laptop is. I do not want to recommend solutions to people,
that only burn out the charge management in a laptop a month
later. That's what happened in at least one case here.
That was the anecdotal evidence, that a mismatch on
barrel voltage, put something under stress. Someone visiting
had a shit eating grin on their face, over the "universal"
product they bought. A month later they wrote back to say
the laptop would no longer charge, with anything.

If you have a USB PD laptop, go for it. Otherwise, do not.

Okay.

H11: 16V 4A 6.5*4.5mm 19.5v 3.3a 4.7a 6.5*4.4mm
So the barrel adapter H11 works with both a 16V laptop
and a 19.5V laptop ??? Most of the other barrel tips are playing
the close enough game, when they might not be close enough.
It could just be using a fixed 19V output when the USB PD
protocol is not detected. The advert is pleasantly unclear
on the matter.

Paul

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From Newsgroup: sci.electronics.repair

On Tue, 4/1/2025 10:40 AM, micky wrote:

I only wanted that to charge my phone. Had a hotel and used the
computer there.

But when I do foreign travel, even if I have rented a room, it can be
too far to drive back at night just to return the next morning, so i
often sleep in the car, and use the laptop before sleeping and in the morning. (ne time I used while driving it to find a particular stream
in a "park" and I got interested in having GPS for the laptop, but none
of them had iirc very good reviews and now I can't remmeber why the
phone wasn't good enough anyhow.)

But I will make sure any rental car in the future has a cigarette
lighter. or power port and young'ns call them.

I have a GPS here from Adafruit that seems to work OK.
It can pick up a few birds while sitting in the house and
sitting on a window ledge inside. (It can see seven satellites,
but only two have "green" signals and full signal strength
inside the house.)

It can scan some number of channels, and once it has acquired
a set, keep those working channels operational, and get a result.
It might deliver four messages per second, serially. You can
program the baud rate.

The trouble with hobby designs, is they're not packaged for
trips (too many wires). A commercial one will be a blob and a single cable.
But we don't know how technically sophisticated those are.

And as the standards for these slowly change, eventually
you might need a new one, for some whizzy quality improvement.
For navigation, you don't need bomb-site accuracy.

The Adafruit one has a PPS signal (Pulse Per Second) and
the edge of that signal is fairly precisely aligned to the
official time. It's hard to get that edge into the computer
without degrading the precision. That should be able to do a
better time alignment, than the Windows w32time over-the-network
update.

Paul
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From Newsgroup: sci.electronics.repair

On Tue, 1 Apr 2025 11:54:38 -0400, Paul wrote:

I have a GPS here from Adafruit that seems to work OK.
It can pick up a few birds while sitting in the house and
sitting on a window ledge inside.

You cannot always count on windows being a good portal to
the outside, wireless word. Most new'ish windows these days
use "Low E" glass. Low E glass is essentially standard clear
glass with a microscopic, transparent, metallic coating on its
surface that is better at reflecting heat than the glass itself.
The coating used in low E glass tends to be that of a
low-emissivity metal, such as silver.

Add to that the Faraday effect that a stucco siding presents,
and you'll understand why it can be frustrating to use a
cell phone inside my home.

And then there are the metal roofs adding to the mix with
GPS devices....

Jonesy
--
Marvin L Jones | Marvin | W3DHJ.net | linux
38.238N 104.547W | @ jonz.net | Jonesy | FreeBSD
* Killfiling google & XXXXbanter.com: jonz.net/ng.htm
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From Newsgroup: sci.electronics.repair

In sci.electronics.repair, on Tue, 1 Apr 2025 11:54:38 -0400, Paul <nospam@needed.invalid> wrote:

On Tue, 4/1/2025 10:40 AM, micky wrote:

I only wanted that to charge my phone. Had a hotel and used the
computer there.

But when I do foreign travel, even if I have rented a room, it can be
too far to drive back at night just to return the next morning, so i
often sleep in the car, and use the laptop before sleeping and in the
morning. (ne time I used while driving it to find a particular stream
in a "park" and I got interested in having GPS for the laptop, but none
of them had iirc very good reviews and now I can't remmeber why the
phone wasn't good enough anyhow.)

But I will make sure any rental car in the future has a cigarette
lighter. or power port and young'ns call them.

I have a GPS here from Adafruit that seems to work OK.
It can pick up a few birds while sitting in the house and
sitting on a window ledge inside. (It can see seven satellites,
but only two have "green" signals and full signal strength
inside the house.)

It can scan some number of channels, and once it has acquired
a set, keep those working channels operational, and get a result.
It might deliver four messages per second, serially. You can
program the baud rate.

The trouble with hobby designs, is they're not packaged for
trips (too many wires).

I see what you mean: https://www.adafruit.com/product/5440

A commercial one will be a blob and a single cable.
But we don't know how technically sophisticated those are.

And as the standards for these slowly change, eventually
you might need a new one, for some whizzy quality improvement.
For navigation, you don't need bomb-site accuracy.

The Adafruit one has a PPS signal (Pulse Per Second) and
the edge of that signal is fairly precisely aligned to the
official time. It's hard to get that edge into the computer
without degrading the precision. That should be able to do a
better time alignment, than the Windows w32time over-the-network
update.

I really can't remember why the phone was not good enough. Surely it
wasn't just because the screen is so small. And I did find what I was
looking for. I'll probably remmeber next time in the same situation,
but until then, I will just ponder it.

Allon, I only do stuff like this in good weather so I'd probably have
the car windows open. But not the windshield, rear window, or roof. :-(

Paul

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