Friday, August 27, 2010

In praise of LEDs

Lately I've been getting back into electronics again, something I messed around with a lot as a child but didn't really understand (I thought like an artist, not an engineer) but now am having great fun with.

I started back into this in order to build a little microprocessor-based controller for my refrigerator, which would measure voltage and then shut off the refrigerator when the sun isn't shining and batteries aren't charging, so as not to run down my batteries. The refrigerator is a TEC, and it uses 4A, and has no thermostat built in, so this is important.

But, also, I discovered that many basic facts of electronics and electricity weren't in my grasp. I'd skipped over them, thinking the stuff was "magic". Now that I've purged magical thinking from my life, I can approach this with a new mind, an open one, and realize that it's all just electrons flowing and they obey basic laws (Ohm's, Kirchener's, etc.). So I'm re-learning all the basics of DC circuits, from scratch.

Along the way I discovered I needed more light in here to work on electronics projects. In keeping with trying to reduce my electricity usage, and to test my understanding of the laws of DC circuits, I decided to build myself LED lights.

I love these things. I recommend them to any and every vandweller. They are cheap, and easy to build. You just buy the raw white LEDs online or from your local electronics store, solder them together, and you've got light. Thanks to the Internet, you don't even have to understand Ohm's law in order to design your own lights, just use this: You can run them off of 12v easily.

LED lights are very bright, and they use very, very little electricity: less than a watt for even a decent-sized array.

After destroying two flourescent lights (flourescents don't seem to like working off of a Cobra "modified sine wave" inverter, sadly), I'm hooked on LEDs. Let there be light!

Thursday, August 26, 2010

Pit toilet splashback is the nastiest

I've spent most of the past 3 years urban camping, but over the past few months I've done quite a bit of camping at actual campsites and out in rural areas.

I have to say, splashback from pit toilets is the absolute nastiest thing I've experienced yet. From 20 feet down comes-- straight up at you and onto your body-- a vile splash of ammonia, chemicals, and who knows how many people's effluent. Grossest thing ever.

In urban areas, I have to say the only thing that has come closest have been BART bathrooms. BART has the nastiest bathrooms ever; they're worse than any gas station I've ever been in.

I've generally had good luck with portapotties, both in urban areas and in rural campsites.

Also, I finally learned how to do a proper cowboy shower (a spongebath). It works really well! I still like my urban camping strategy of staying within a few miles of somewhere that my gym membership is good-- hot showers and running water are really nice-- but it's also good to know that with about a gallon or so of water and a washcloth and towel, I can stay pretty clean no matter where I am.

Monday, August 16, 2010

Painting and maintenance

I successfully painted some rusty and weathered parts of the van. Looks a lot better now. I hope I stay grafitti free.

Also, being out in the HOT made me realize that I didn't have enough ventilation. I have a 13.5" square exhaust vent, but only a 9"x5" intake vent. This was no problem when I had the roof bare, because the aluminum roof would pull air up and force it to circulate by convection. Basically, it was a huge stovepipe. But since putting in the drop ceiling, it stays beautifully cool here in the morning, but once it heats up, it's impossible to cool it down again. It was miserable in here with even 70-degree weather. So I cut an additional intake vent, which helped a lot. Convection seems to be occurring again, and also the fan doesn't have to work too hard to circulate the air when I turn it on.

I found another problem too. Even though it's very dark and very well-insulated in the box, that aint' so in the cab. The cab is covered with windows on three sides and gets like a huge solar oven-- if it's 70 outside, it's 90 in the cab. The problem is that way too much of that heat was radiating through a fiberglass "dent" behind the driver's seat (it's there to allow the seat to slide backwards) and through the wooden box door. So, I bought another sheet of isocyanaurate insulation to cover those and stop the radiation.

I'm happily back in the fog zone again, and I've noticed that the extra vent helps solve a lot of the dry-mouth problems I was having. Maybe that will help solve some of my dental problems.

Friday, August 13, 2010

Strangest break-in attempt ever

I needed to do some painting, so I needed to leave the 50-degree fog belt and find someplace with less than 50% humidity and temperatures over 70 degrees. So I ventured out to the way far white-bread rich distant reaches of the bay area, where the wealthy lead sheltered lives amidst their million-dollar 1960's Eichler tract houses.

Parked happily (and quietly and safely) in the hills, I'd left my driver's side door unlocked. Around dinnertime, and just before dusk, two pre-teenage girls skipped past my truck, then stopped. And whispered to each other. Then one opened my door, and climbed into my cab, while the other took a picture! Then they ran off down the hill, giggling.

I was a more than a little stunned that those young girls should had absolutely no fear at all. They saw a big white truck, and thought it was something to play with. They obviously live an innocent, shelterd life so completely homogenized, so completely devoid of any crime or danger, that they saw nothing to fear, and decided to play instead. It was completely opposite reaction to what people in middle-class suburban areas closer to the city have: they're damned paranoids, and they eye me warily or even call the cops on me.

It was similar to the level of acceptance and lack of fear I get in rural areas, or in working-class suburbs: just a big work truck, nothing to see here.

But there was a different element to this, one which concerned and annoyed me: not only in their innocence, but also their arrogance. This wasn't their truck. They had no right to be in it. Where did they get the idea that they could just jjump into other people's vehicles? Maybe everything on their block is so safe and they all just share stuff, so this is no big deal to them. But I doubt that. More likely, there was a rich person's arrogance, that an obviously working-class person's truck is just not to be taken seriously. A kind of "let them eat cake" attitude, like my truck was just a peice of junk left on the sidewalk for others to pick up and do with what they will.

I got a bit worried because of this, and I was concerned that their teenage brothers might come around with spraypaint and demonstrate their sense of entitlement in that way. But no, I made it through the night quite safely and happily. Alas, the fog followed me, so the next morning it was just as foggy here as by the ocean. I kept driving and eventually found an even sunnier spot.

Wednesday, August 11, 2010

Yay Cobra

I bought a Cobra CPI 2500 inverter in December 2007-- in fact it was one of the first things I bought for the van, even before I'd bought the actual van (solar panels and batteries were the next things I bought, a week or so later). I installed it, and used it mostly to power my LCD panel display, but since switching to a netbook I don't even have the LCD in the van anymore (it's in storage), and I use the inverter only for occasionally running a flourescent work light or a vacuum cleaner. It worked, until it didn't.

The inverter just died a few weeks ago. Stopped working entirely. So I boxed it up and shipped it back to Cobra. I don't know what kind of warranty it came with, but they sent me back a brand-new unit of a totally different model, a CPI 2575 with a bunch of new digital bells and whistles (voltage/wattage indicator, USB power port, etc.). It's a lot smaller than the old unit too, which is nice, but it's also of a lot more cheap/flimsy construction-- this one is mostly plastic when the other one was almost all aluminum. And it's noisy, not only when running, but it emits a crazy and obnoxious set of beeps whenever it starts up and a short one when it shuts down.

But the new one works, and they didn't charge me a dime, even though the old dead unit was quite possibly out of warranty. Nice job Cobra. I hope this one lasts a lot longer.

Wednesday, August 4, 2010

The wheels on the van go round-ish and round-ish

I've noticed for a while that the rear wheels feel "lumpy", especially at low speeds-- they don't seem round. And they don't roll, I have to use a lot more fuel to get the vehicle moving and it doesn't coast, it just stops and I have to give it more throttle. I do not like any of this.

I thought maybe my wheels were out of round, but I asked a tire shop to spin them, and they're plenty round. And still the problem persisted.

I loaded down the van to haul some stuff, and noticed that the passenger's rear outer tire was bulging out the sidewall. Hmm. A vandwelling friend hipped me to the physics of tires. Apparently I'd run over enough curbs as to damage the belts of the tire, and caused a lump. I decided to spend $50 on a used tire to see if this was indeed true. And it was! New used tire (got a good deal: 65% tread), rides smooth like glass. No more lumps. The van coasts from one stop sign to another, almost from one traffic light to another, no throttle.

And I learned the secret to not running over curbs. Pull way far IN to an intersection when making right turns, until I'm practically hitting oncoming traffic. That's the only way for my rear wheels-- 17 feet behind me-- to clear any curbs. Between these two things, hopefully I can keep my tires running longer.

Sunday, August 1, 2010


For a few years, I had a pretty good system going: I'd buy 5lb block ice at a few places near where I was often located anyway, round the square edges off by smacking it with a hammer, then stuff it into a very cool stainless steel ice bucket I bought at Smart & Final for like $20. The block ice would last 5-7 days on average (unlike 2-3 days for ice cubes or 1 day for crushed ice). When the ice melted, I'd dump the water into my 1 gallon cleaning water container, which had a hose and a spraybottle nozzle, and that would be my cleaning water. Efficient and easy!

But I was getting really frustrated with dealing with ice though. It was getting expensive: $3.50 a block. Block ice is only available in a few places, and I wa finding myself in those areas less and less. With biodiesel up to $4/gal now, driving from where I was, just to get ice, was an extra $5 cost or more! And some of the places started to run out of it more frequently.

So I trolled Craigslist and found an Evercool electric TEC cooler for $75, and bought it. It's interesting.

It is a TEC, so it cools only to 20 degrees below ambient. So, in 60-degree fog near the Pacific Ocean, it'll refrigerate food to 40 degrees. But anywhere else, it's just a cooler, and the food will spoil. I suppose I should keep my ice bucket around for dealing with hot weather.

Also, it's noisy. The fan is on ALL the time, it has no thermostat. The fan is about the same loudness as my netbook, but I don't try to sleep with my netbook on. And, it uses 4A at 12v. That's twice what a TruckFridge uses, but a TruckFridge is like $600, and this was $75.

So I first of all built a cabinet for the cooler, and insulated it to keep the noise down. I've got ducts to its intake and exhaust, and will run them outdoors for better cooling and also for noise reduction. I'm building a little microcontroller thermostat for the cooler, to run it on a sparse schedule on cloudy days to allow my batteries to charge, and on an even sparser schedule at night to avoid draining the batteries too much in the first place.

I enjoy not having to scramble around getting ice anymore though, at least in cool weather.