A few Lab members recently asked me “how do you survive power outages?”
Here’s how, and it’s all available at your website or department store of choice (cough cough Amazon, Wal-Mart)
One (1) marine deep cycle battery, as large as you can afford
and/or can carry (approx $80) (must buy in store)
One (1) 12 volt trickle charger (approx $30)
One (1) 12 volt to 120 volt inverter, sized according to your needs. 200 watts will power a few devices for around $40; do yourself a favor and get a 600 watt Tripp Lite or similar, around $90
Optional: One or more 12V accessory plugs, to wire into battery (approx $10/ea)
My current “Power Box”, pictured below, is currently out on an off-grid island staged and waiting to run some Civic Wireless customer premises equipment. The box will run network gear on a small inverter for weeks on a full charge.
Part 2: Exploring solar trickle charging.
Questions? Email: help [at] civicwireless.org
With some inspiration from the potential snow storm last week, I endeavored to test my emergency preparedness for heating my apartment when the power is out. I never did lose power, but the test was successful and I am happy to know that if I did lose power in the winter, I can keep warm at home.
I attached an inverter to a marine battery, then plugged in my Rinnai heater and it ran just fine. The Rinnai does buzz a bit loudly, but that’s because the inverter does not produce a “true-sine-wave” signal. I tested the setup with a box-fan attached to the inverter as well and it worked fine.
With the fan and the heater both running on LOW the draw was 115W. Some quick and super dirty math approximations tell me that the battery (if fully charged) will run this about 11 hours. This would be longer if the box-fan isn’t running (less power would be used).
105 Amp hours (sticker value, full charge)
105 Amp hours x 12v = 1260 watt hours (approximate average voltage)
1260 watt hours / 115 watts = ~11 hours
Of course, the inverter can be run from any 12V source. My Honda Civic has an alternator with a faceplate rating of 70Amps. Some quick math tells me how much power this can potentially provide.
70 Amps x 12 Vdc = 840 Wattsdc
I believe the inverter is well within the ability for the alternator to run. So the car could potentially run the inverter as a generator as long as there is gasoline in the tank.
Check out the rest of the info and pictures at my blog.
I recently found a great set of posts about what a trolley is and how they work at Nathan Vass’ website. The short version is that a trolley is an electric bus that gets its power from overhead lines. There are many advantages to using a bus with rubber tires over a train (can change lanes, can avoid obstacles, climb hills without wheel-spin) and many advantages to using an electric bus over a diesel bus, the main reason being torque to climb the hills of San Francisco.
I originally became interested in the topic last year when I visited San Francisco. There were many things I liked about the city that appealed to different interests of mine (city planning, green spaces, diverse cultures), but one of the things that stuck out to me was the infrastructure for the trolley system. This was not something I had expected.
When you look up while downtown, just below the common sight of power lines at the top of the utility poles, you see what looks at first like a rats nest of electric wires. This is especially so around intersections in the road. But upon further examination, patterns emerge. I noticed that the wires were running in pairs of parallel tracks, and where one track crossed another, one of the pairs would have some extra hardware.
I only spent a moment trying to figure out what they could be used for when one of the Muni buses (a trolley) passed me on the street. These are quiet, exhaust-smell free giants of public transportation that I was instantly in love with. And this post isn’t about public transportation overall, but if you need an explanation as to why it is good and how a bus can greatly reduce congestion, this GIF explains it beautifully.
Since my previous post I have added a couple additional temperature sensors to my piHouse project. One is an outdoor temperature sensor that I previously programmed but never installed outside, and the other is a new sensor in my bedroom. This involved some hardware planning and effort installing because I had to run a cable through the house and outside, but once I tested the new cable run, it was relatively simple to duplicate the software for the sensors I already had.
The part of this that took the most time was pulling the cable and then soldering the connections. The biggest problem I have is placement of the outdoor sensor. I am having issues with direct Sunlight.
Here are some highlights, you can find the whole story here. This time I also include some examples of the commands I use on the raspberry pi to obtain the data.
When testing my hardware connections, I use this command to ask the pi to take a reading and then display the result to the command line:
The Laboratory B crew had a great time at this year’s two day Champlain Mini Maker Faire! This year we had additional support from FairPoint Communications to allow us to teach kids & adults how to solder. We had really impressive students this year, many of whom have seen us before at the previous events. Many people were coming back for their second or even third time. Good work everybody and thanks for coming out to see us! As usual, if you had trouble with your kit or ran out of time please feel free to swing by the Lab, but let us know your coming ([email protected]) Awesome!
Laboratory B is all set up and ready to see you at Champlain Mini Maker Faire this weekend! The event is on Sat. October 4th 10am – 5pm, and Sun. October 5th 11am-4pm at Shelburne Farms in Shelburne Vermont.
“Join the folks at Laboratory B for a self-paced soldering workshop. We bring the soldering irons and the kits, you bring the desire to learn. We will have kits from SparkFun and all the required supplies and safety gear for you to sit down and learn how to solder, and when you finish you take the kit home! Have you soldered in the past but are not familiar with some of the newer techniques such as surface-mount soldering? No problem! There will be beginner kits, intermediate kits, and advanced level kits to fit all skill levels.”
It could use a little improvement if anyone is interested in forking it! It needs some testing with binary files. It needs a way to store the length of the message. And ideally, it’d use a pre-shared key (maybe?) to allow you both: A. define where the payload is hidden in the image, and B. actually encrypt the payload (which is, as of now, unencrypted). Which makes it so it doesn’t follow Kerckhoff’s Principle [wikipedia].
…Unfortunately every single message is decoded as “Drink more ovaltine” [youtube] (…just kidding. it’ll do whatever payload you want)
When Laboratory B got started we were excited about the possibility of other hacker/maker/community workshop spaces starting up and sustaining in Vermont. That’s why we created Vermont Hackerspaces Inc as non non-profit designed to help others do great things. The Foundry is a community workshop getting started in the Northeast Kingdom. Building on the grit, and hard work they are going to bring together a community of creators, tinkers, crafter, artist and entrepreneurs. This great community is going to build a great new space for creation and innovation!
On July 7th, Vermont Hackerspaces Inc, agreed to become the Foundry’s fiscal sponsor while they get started. The Foundry is looking to develop it’s own 501(c)3 but it’s a long when from getting going to handling your own books. Check out the website or Foundry’s facebook page and Foundry Info Pack for more info.