August 2007 Archives
A watershed of 21st-century childhood development: following your directions, your toddler retrieves the specific remote control you need.
Every so often when I'm rearranging electronics at home and feeling overly fastidious, I run through a brief thought experiment about how to move something to another outlet without turning it off. The basic idea is something like this:
1. Start with a device plugged into a power strip.
2. Create an unholy power cable with male prongs on both ends.
3. Plug a UPS into the power strip using the unholy cable.
4. Now the device is running off both house current and the UPS!
5. Unplug the power strip from the wall, then move the device.
I've never had the guts to actually try this, and I think I've figured out why it will lead to misery, or at least unexpected behavior. The power from the grid is a sine wave, and DC devices depend on the oscillation to convert the AC to DC. If you introduce another power source into the mix, the waves won't be synchronized, and the device won't be able to convert sufficient power to keep going.
I'm sure there are other problems that will lead to worse consequences, no doubt involving the fire department. But this seems to be at least one independently sufficient reason why Radio Shack doesn't sell male-to-male power cables. (I'd be happy to hear the whole story from an electrical engineer; please comment.)
Updated 11/06/2007: Someone figured it out!
I know three people who made it as far as soloing an airplane, but then stopped their instruction and to this day haven't gotten their license. Each had a surprisingly similar explanation: work and/or life got very busy, lessons got delayed, and... well, that was that. This is no doubt a good reason to stop training for one's private pilot license. You need your head in the game to stay safe and thrive in the cockpit. But it piqued my curiosity that of these three people, all three stopped at roughly the same point in their training. I respect each of these guys and know each of them to be thorough and disciplined in their various professions, so I had no reason to believe I'd be immune to whatever got them. I had a persistent fear that when I reached the same milestone, I, too, would abandon my pursuit.
This morning I completed my second solo flight, meaning I'm more or less at the point that I've worried about. And sure enough, I now think I understand the intense desire to quit. It's not a single thought process or emotion, but rather a set of feelings that are battling themselves viciously. The outcome is that solo flight during one's pilot training is anticlimactic, exhausting, and unenjoyable, and when that sort of experience competes with the rest of your life... well, that's that.
Why anticlimactic? Read any old-timer's account of his first solo. You'll go misty-eyed; it sounds like the most romantic experience one can have without anyone else helping. And yes, it's a great accomplishment, but it's quick, and afterward, all you feel you've proven is that you're not abnormally susceptible to panic attacks during times of stress. Granted, my flying club doesn't have much of a tradition of shirt-cutting or the like, but I don't think that would have made a difference. It's just a repetition of what you've been learning for weeks or months, but this time without your CFI in the right seat. That's the point, of course; your solo should be anticlimactic and uneventful. You can't win; either your hundredth flare is just like the first 99, in which case it really doesn't matter that it was your first solo flare, or your hundredth flare turns out to be "special," and you get to pay for a prop strike. In probability terms, your solo has negative expected value.
At this point you've completed an amazing, spectacular rite of passage that by definition must be a letdown. And now they hand you the keys and tell you it's OK to take the plane out by yourself again. But you can't take anyone with you, you can't actually go anywhere useful (your first solo endorsement usually allows you to take off from and land at exactly one specific airport), you can't go near or even over clouds, and even if you were allowed to use any of the cool navigation equipment in the plane, there's no reason to, because you aren't permitted to go far enough from your home airport to get lost. This pretty much means you get to take off, fly in circles for 30 minutes, and land.
By describing these solo flights as mundane, I don't mean to make them sound easy; in fact, they're terrifying. Did I preflight the plane correctly? Did I somehow drain all the oil when I brushed the fuselage, thereby dooming myself to attempt The Impossible Turn shortly after takeoff? Did I leave the flaps down? Did I just decapitate an entire class of children on a field trip when I started the engine? Am I about to retract the landing gear while still on the runway in my non-RG Cessna 172? Am I taxiing to the wrong end of the runway? Will I decide today that P-factor pulls to the right? Will theoretically possible but never-before-observed infinite low-hill updraft suck my plane up to Flight Level 1000? Wait a minute, am I in Bravo airspace right now? If I turn back into Echo airspace, will SFO Tower's Sidewinder missles that are surely screaming toward me also turn back? Am I about to intercept a wayward skydiver? Is Tower screaming "CESSNA DESCEND NOW" at me, but I've foolishly just switched to ATIS? Or worse than any of these fates, does somebody in the control tower think I'm an idiot???
A choice is before me: either take two hours out of my day to practice squelching my inner voice that's screaming in terror, or stay at work and write a few more unit tests. I admit, it's a tough decision. I'll continue flying in the hope that my gut reaction to a solo flight becomes "yeah! woohoo! let's go!" rather than "err, yeah, that's substantial risk for insufficient upside, I'd rather not." Meanwhile, nowhere on my checklist does it say to have fun, and I sure as hell am not straying from my checklist.
Last week I wrote about getting my feet wet with a PV solar energy project. Here are more details.
The camping trip is Burning Man. The purpose of generating all this power is a magnificent 200 square-foot shade structure with mood lighting, music, and a drive-in (OK, walk-in) movie theater in the evening. We'll be camping in Kidsville so we expect to get a fair number of toddlers in the audience, and video content will be chosen accordingly.
The mood lighting is strings of icicle LED Christmas lights that together will consume about 25 watts. The music is a desktop PC speaker system with subwoofer (50 watts peak). The projector is a Mitsubishi PK-20 pocket projector (50 watts peak), which is LED-based and isn't too bright, but will work fine at dusk.
I have two 108-Ah 12-volt batteries that I hope will get topped off to capacity each day by the 120-watt solar panel. Doubling my estimates to be conservative, and adding some extra wattage for miscellaneous usage like laptops and AA battery recharging, we should easily get five hours of power each night with everything cranked up to the maximum.
If we choose to ignore the environmental impact of manufacturing the gadgetry and driving it 1,000 miles round-trip in a gas-guzzling RV, then it'll be the greenest movie theater ever!
I have purchased the solar panel and charge controller, and will do a test charge over a few days this week. Then this weekend I will put up the shade structure in my yard, hook up the theater, and confirm power consumption with my Kill-A-Watt. That leaves one full week before we leave for the Playa, which is probably a record in terms of advance Burning Man project completion.
It's been almost ten years since I left Los Angeles. One of my best L.A. food memories is a little restaurant called Hurry Curry. I always ordered the same thing: steamed rice with a bowl of Japanese chicken curry poured over it. You had to ask them to make it about 10x hotter than their spiciest in order to get any real kick, but once you did, boy was it delicious.
I visited Pasadena recently and thought I was hallucinating when I saw a Hurry Curry across the street from the downtown Coffee Bean. But sure enough, they'd opened a second location, and it was just as good as the first. It made me miss L.A. even more.
If you know of a place on the Peninsula that sounds like Hurry Curry, please let me know. Meanwhile, here's a recipe I made up that is a fast-food MSG-laden facsimile of my favorite curry dish:
White rice
1 chicken breast
1 cup of water
2 cubes S&B Golden Curry, hot
Steam the rice. Fry the chicken. Boil the water and toss in the curry cubes. Reduce to simmer. Slice up the chicken and put it in the curry. Let it bubble for about 15 minutes, and then pour it on the rice. Makes one serving. It's possible that you can skip the chicken-frying step, but I'm not sure how much longer you'd have to simmer. I fry the chicken so I'm sure it's cooked all the way through.
Two problems:
1. The CSS just ain't right, as far as I can tell. Go to Design -> Templates -> base_styles.css. Find the p element and copy it into its own separate block. Change padding to 0px 0px 20px 0px and rebuild.
2. Thanks to Joe Siegler on the Movable Type forums for this: change convert_breaks="0" to convert_breaks="1" in the three places it appears in the RSS/Atom feed templates.
If you've bought a car in the last decade, you might have a remote control on your keychain that locks and unlocks the doors. This is convenient -- so convenient that the experience of locking the car is no longer memorable, and I often find myself wandering away from my car and then worrying that I forgot to lock it.
Here's my invention, which I hereby dedicate to the public domain, that helps solve this problem. For 15 minutes after you press the lock button, a tiny green light on the remote control blinks every 5 seconds. Or maybe a little LCD says "Lock OK." Whatever the implementation, when you realize that you don't specifically remember pressing the lock button, you can find out by looking at the indicator. It doesn't guarantee that the car is actually locked, of course; it just confirms that you pressed the button recently, and that's generally good enough for worrywarts like me to relax.
I'll be going camping soon in a sunny place, and was thinking of using this trip as an excuse to start on a long-term project of building my own grid-tie PV (photovoltaic) solar system at home. I'm asking you, person who probably arrived here via a search engine, whether this is a workable idea.
Allow me to play the part of Basil Exposition for a moment: "As you may know, gentle reader, grid-tie systems are connected to the electricity grid, which generally means that they supplement a home's electricity, rather than being the sole source of it. A typical system consists of some PV panels that convert solar energy to DC electricity, an inverter that both converts the solar DC power to AC and connects the system to the power grid, and optionally a charge controller that delivers power to deep-cycle batteries, which store excess power for use at night time."
For the camping trip, the basic strategy is to buy one of each part of the system that can be bought piecemeal, and then buy inexpensive, relatively throwaway versions of parts that are expensive in a full-blown system. I'd buy one 120-watt panel (about $600) and a cheap charge controller (about $50). I'd then use a couple deep-cycle batteries and a little inverter that I already own. On the trip I'd use this power to charge various battery-powered devices, such as a laptop computer. (We'll ignore the annoyance that I feel knowing that 12-volt DC gets converted to 120-volt AC and then back down again to around 12 volts to charge batteries, no doubt losing at least 40% power in the process.)
On my return, I'd put the panel on the roof of my house and try connecting my desktop computer to it (via a UPS so I get a warning if power's low). I use that computer for perhaps a few hours a day so it should work.
Eventually, after research, and hopefully your feedback, I'd shell out money for a real grid-tie inverter (at least a couple thousand dollars) and charge controller (also thousands of dollars), and then add a few more panels and batteries. If the efficiency worked out, then I'd scale up the system -- having already bought inverter and charge controller capacity to handle the extra power.
The alternative is just coughing up $40,000 and having someone come in and install a complete system this weekend on my roof.
Advantages of the roll-your-own approach? It's an interesting hobby project; it commits less capital up front. To the extent that PV panels come down in price as technological advances occur, I get the benefit of lower prices in the future.
Disadvantages? It might fail because I don't know what I'm doing; I get the worst possible return on the large components until I fully utilize their capacity.
What do you think? Silly idea?
Although it's important for a retail business to fulfill orders correctly, in some ways it's even more important for them to do a good job of fixing fulfillment problems. I'd like to award the first-ever Sowbug.org Gold Star For Excellent Customer Service to mypilotstore.com for their fine handling of a mixup.
I ordered a Garmin GPSMAP 96C (this is a GPS device but for an airplane instead of a car), and when the UPS tracking info arrived, I scheduled a flight accordingly so that I could take it out for a spin. Unfortunately, on Friday a box arrived with a 96 in it, not a 96C. Although the differences between these models are only cosmetic, I definitely wanted the 96C, and I couldn't fairly use the 96 over the weekend and then return it, because then the seller couldn't legitimately sell it as new after that. So I was stuck.
I cynically emailed the retailer, expecting to get a "mailbox full" bounce or at best a reply some time the following week. Instead, less than 20 minutes later I got a shipment notification from UPS, as well as an apologetic email from the retailer explaining that they'd just overnighted the correct model (not just overnighted but with Saturday delivery). They included a shipment label for me to return the other device.
Sure enough, Saturday morning the box arrived, and all was well again in the universe.
One of the big fears of shopping with an Internet store is what happens when something goes wrong. I have no such fear with these guys. I regret that mypilotstore.com sells only aviation supplies; I'd be willing to buy anything from them.
Some time in the past year or so, all my family's geegaws and gadgets suddenly became mini-USB powered. Instead of my Nokia phone using one kind of wall wart, and my Sandisk MP3 player using another kind, our Motorola phones and my iRiver MP3 player are all recharged by the same kind of cable.
This is convenient because I got rid of all the proprietary power adapters, and it's now possible to carry a $2 USB-to-mini-USB cable with me and plug into just about any computer in existence for a quick device recharge.
But the downside is that computers have now become the most expensive power adapters on Earth. In the past, I've left my computer on overnight solely to charge my phone -- and as a bonus once I forgot to re-enable the hibernation feature when I was done, so I actually left it on for a couple days after that. Assuming the computer consumed 100 watts for three days, that was 7.2 kilowatt-hours at around 35 cents each, or $2.52 to charge my cell phone. Granted, that's not a fair calculation given the extra couple days of accidental on-time, but I'm sure it's quite common these days to leave a computer on overnight to charge a device, so that's at least 42 cents spent versus the few cents of power actually consumed for charging purposes.
My solution? I'm going to try something like this: yet another geegaw that will probably consume less than 5 watts, assuming 30% efficiency (still 3.6 Kwh/month or $1/month), if I leave it plugged in all the time.
Two steps forward, one step backward.
Update: It turns out those Motorola bastards use a special cable for charging their devices. I could easily make a cable with the required 165K resistor, but this defeats the purpose of having a single power source and plug for all my devices. Meh.
Second update: It pains me to admit this, but at least other devices are compatible with the screwy Motorola power adapter. So I can use that for charging all my devices.
