Universal power supply for PCs, setting voltage

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

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

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

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 first one I listed above had none.

Okay.

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

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

I see what you mean:

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. :-(