I have the power

On my recent trip to South Africa, I wanted to be able to power my laptop from the plane's power jacks during my flights if possible. I'd heard that there was such a type of power supply, but I didn't know what it was, and I didn't end up trying to get the right supply until right before I left.

The most common power jack on aircraft is called an "Empower Plug". It's a special jack that supplies up to 75W of 15V DC electricity to your portable device. Here's a photo of one of mine:



A common accessory for laptops is to have a power supply that runs on a cigarette lighter plug, so that you car run it from a car power jack. However, the Asus Eee doesn't seem to have one, so the only way to power it from a DC vehicle source is to have an inverter that takes DC power and produces AC wall power, and then you power the Eee from the normal wall power supply. Although this adds a step, I guess this is the only way to power my laptop on an airplane. So I went shopping, at the stores that I had available to me.

Wal-mart did have an inverter:


I tested it out on my battery pack; it ceased to work immediately without ever successfully powering my laptop.

I also ran across one at the local auto-parts store:


This one worked fine, but it had a really noisy fan in it. I took out the fan (another blog post), and it still worked Ok from my battery pack. I took it along on my trip. It did NOT work on the flight from Philadelphia to Heathrow. I'm not sure why; maybe the connector was the wrong shape (it seemed like it never did fit right).

After leaving South Africa again, I bought another inverter in Heathrow:


which worked on the flight back to the US. Yay! Having bought it in Heathrow, of course, it puts out 240V AC and has a UK/EU power jack, rather than a US power jack:


(I think that this is the US power jack equivalent).

Fortunately, I also have a Yung-Li power adapter from the old South Africa plug standard to a US outlet


which then converts the inverter to one that effectively has a US outlet:



By the way, before heading to South Africa, I did manage to get the right plug adapters to power my laptop and such:




These are of the very excellent Taiwaneese "Yung Li" adapter series. The South Africa adapter is the YL-8015. It's tough to find a place that sells them; I finally bought mine at Signal and Power Delivery Systems. (It's tough to find in their catalog, but they have them, and they will sell in small quantities.)

damn stores these days

I had a major grumpy old man moment yesterday. Since electrical stuff is something I'm interested in, I feel that it's incumbent upon me to install after-market devices in my beetle as a way of customizing it. I'd like to have a mount for a GPS that's powered from the car, and since it currently doesn't have a working radio at all, before I take it on any major trips, I'd like to install a Sirius radio in it.

By the way, reason I went with Sirius over XM is that Sirius carries NFL football games, so that means that I can't listen to Indy Car racing...oh well. The radio display that they have for games is neat:


Instead of title and artist, the lower two lines of the display list the teams playing and the current score. That way you can flip to another channel and get the score of another game quickly. A clever way to make the experience more efficient.

Before I start hanging extra devices on the electrical bus of the beetle, which isn't that robust anyway, I want to have instrumentation on the electrical system. I want to have meters to measure the voltage of the system and the current flowing to (or from) the battery and the total electrical draw. I went to Radio Shack thinking that they would have something. Well, it turns out they don't. Not a single blessed panel current meter in the store, and the clerk's method for searching for it was to log onto the Radio Shack web site and search for it there. I could have done that from home, thanks.

And that was my Grumpy Old Man moment. As recently as 1995, Radio Shack was an electronics gadget store; that is, if you wanted to build something out of wires and components, that was where you went to get the parts. I guess that they as a franchise are following the path that they need to to survive, but it saddens me that what was once a paragon of useful stuff is now primarily a reseller of digital TV items, cell phones, and crappy remote control toys and stereo equipment. Granted, they do have some amounts of component-level merchandise, but that's like 20% of the store or less.

idiot light

In an ideal world, all vehicles would have at least one gauge, preferably two, indicating the state of the electrical/charging system. Ideally one measuring the main bus voltage and one indicating either the charging or discharging of the battery.

For reasons of keeping the instrument panel simple, and for economy of manufacturing, many cars don't have either of those, but instead have just a simple light that warns that the charging system has something wrong with it. This light looks like a battery, and in my apparently naive, optimistic little world, this light goes on to indicate that the charging system is having problems. Ideally, the battery light going on indicates battery discharge. In principle, this happens any time the battery is discharging. I assumed it was normally implemented as a voltage sensor; if the charging circuit voltage is above a set value, the light is off; below, and the light is on. Say, if the threshold is 13V, then the normal 14.4V charging circuit value has the light off, but 12V (running on just the battery) it's on.

After having alternator trouble with my 1996 Ford Escort, I found out that apparently this scheme is way to simple for the engineers at Ford that the time this car was designed. What I was told at the Ford dealer the first time I had it fixed (incorrectly) was that the engine computer will turn off electrical components to try to preserve battery life, without ever having turned on the charging light. This defies all logic and reason as far as I can tell. Does anyone know if this is true or not? That the voltage light won't come on, despite the fact that the alternatur clearly isn't working properly, because there are mechanisms that are supposed to be making the battery last longer? If you've had this experience, please drop me a line and confirm this.

The symptoms that happened to me were that the cruise control stopped working, and then the tachometer turned off (engine still running). Not too long after that, it started having trouble staying running, then quit.

the currency of the realm

On the road in Manchester, England. Yung Li plug adapter is earning its keep:






On the way here, I travelled through the Atlanta airport, which I'd always heard bad things about. I found it Ok, if rather spartan. Now that pretty much everyone travels with cell phones and laptops, power plugs are something that one looks for in airports. The Atlanta airport puts a whole bunch of counters with rows of plugs in the food area, which seems like an emminently sensible thing to do to me. They also have free wireless in that area.

The gate area only had a few power plugs, one of which I grabbed. You had the pay for the wireless there, but the view was nice:

not all those who wander are lost

Don't you hate it when you can't find something you know you have? I hate that, and I hate it even more to buy something that I know I already have.

However, after much crashing about the house and muttering, I found our UK to US electrical plug adapters:



Since I went to the effort to find them, I decided to do a brief bit of research, in case I (or someone else) wanted to buy them or ones like them. The specific plug pictured here is a Yung Li YL-6015. There are lots of companies that make adapters that will physically mate one nationality of plug to another. I find that they tend to be chintzy. However, these are very solidly made, and judging by the stamping on it, they conform to the electrical standards of both countries, including the in-plug fuse that's used in British wiring.

Oddly, I went searching for a place to buy those plugs, but I dont' seem to be able to find anywhere. The one place I could find at all was signalandpower.com, and they don't have an ordering page. I ordered these plugs in the spring of 2004, so I don't know where I went to order them; I do, though, seem to remember having to call someone. Signal and Power's contact page doesn't work, but they do have a phone number; maybe I just called them up and ordered them.

Disclaimer: These plugs, like most of their kind, only convert the plug style not the voltage! When in another country, only plug electrical devices into these plugs that are specifically rated for multiple voltages. My laptop power supply, for instance, says "INPUT 100-240V, ~1.0A, 50/60Hz". It will work fine on British 240V 50Hz AC power.

I will take the finding of these to be a good omen for my work day. Which means that I need to get to work. Excuse me, and have a nice day.