I hadn't even finished putting all of said crap out on the curb, when lo-and-behold, your grandmother (likely) showed up and hauled all of the 'treasure' away.
Broken stool? "Check."
Air conditioner with no knobs? "Check!"
Rickety table with typewriter-return sway? "Now I can use a keyboard!"
Sadly, the cat shit remains as a welcome greeting just outside our garage door. Your grandma obviously isn't a cat lady. Gold mine.
...
With the room empty, I began to stage the outlets. What does this mean? As engineer, I have a higher-than-normal propensity to occupy wall sockets at near-peak levels. Thus, I need to strategically plan out where the tables go. Otherwise, I'm likely to place a table insularly from any plug... and what's a table without an outlet? Exactly.
Usually, I like to place the tables such that I can route all the plugs to the table with the minimum number of extension cords. The far side of the room appeared devoid of any plugs, so I staged the tables in the opposite corner (three workspaces total). There was one wall plate that had no plugs... nothing but a blank face. Curious, I opened the box and found a standard 3-wire Romex cable that you'd find in any house built during the last 40 years or so. The odd thing is that this house was built in 1953 – back before trivial things like safety existed – so I knew right away it was not a standard plug. After pulling the leads out, one additional clue was the white neutral lead wrapped with a layer of black tape, indicating two hot leads. Conclusion: my new room has a single phase, three wire 240V plug in it...
...wait for it...
...!!!!!!!!
What does that mean? For starters, if I were European, I could use all my electronics without having to buy a transformer to bring the ass-backwards 120V US grid up to 240V. Also, assuming I had a 3300 Watt, 240V input, 0-300VDC output baller power supply, I could plug it in my room instead of out in the laundry room in place of the dryer. What's that? I do have a 3300 Watt variable output 240V power supply? Oh, well I'll just install that here:
Also, since the entire house lacks a ground (except for one outlet in the kitchen and another in Lee's room), I was able to connect the neutral lead (nominally unused on a 240V three-wire single phase setup) to the ground of one outlet in my room. Now I don't need to daisy-chain an extension cord through the hallway to Lauren's room, which is great because I'd be plugging that cord into a surge protector that is powered by another extension cord that sources from that one outlet I previously mentioned in Lee's room. One day our house will burn down.
So what on earth do I use this power supply for?
To start, I actually have two of them:
They are pretty. Combined, at full output they consume more power than a clothes dryer, a normal-sized air conditioner, or your puny electric car charger. Since they are completely isolated and both voltage and current variable, you can hook them in parallel, series, etc, and derive pretty much any DC voltage you'd ever need at any current you could practically consume.
As previously mentioned, I use the upper supply to charge the electric bike (the original focus of electrosanity). I purchased the bottom supply to balance NiMH batteries, such as the ones in the Honda Insight, Civic, Toyota Prius, and pretty much every other non-exotic electric car on the market. While I only need a 60V supply on the electric bike, I need a 320V supply on these mega-packs since they place all cells in series. Here we are in action, charging customer #1's Insight pack:
I thought connecting wires to spherical magnets was an excellent method to quickly attach/detach voltage/temperature diagnostic leads to the bolts holding the battery bus bars together, but it turns out that heat demagnetizes neodymium. I experimentally determined that it is possible to flash heat the magnet and then attach a lead, but the magnetism is variably compromised and the quick solder job is crap.
Also, it turns out the magnetic surface resistance is highly variable, likely due to minimal surface contact, poor surface malleability, and attracted oxide-debris. Here you can see a terrible 143.4 Ohm path resistance through two magnets:
After experimenting some more, one solution is to place a magnet behind a nickle-plated copper conductor and have the magnetic field pull that known-good conductor into the bolt.
More customers to come (and details), once Lee and I find more time.
...
I finally built an enclosure for a pair of really nice class A amplifiers I picked up from a really crazy electrical engineer during yesteryear's internship:
At idle, they hover at ~140W, equating to 1% efficiency at casual listening levels. Why so inefficient? Class A amps don't have any crossover distortion. The tradeoff is you have to keep the transistors burning full time... I still need to build a power supply that can handle this constant load, but for now I'll keep using the aforementioned baller power supplies.
Note the speakers in the above picture are an $80 set of 15 year old Sony bookshelf speakers... for the money, I've never heard anything better; they are a cherished personal reference.
On the opposite end of the spectrum, the Decentralized Dance Party came to Austin, necessitating a giant gold boombox:
Somewhere in the haze:
...
My commute home involves an 8' fence after 6:00 PM, if I want to avoid a shoulderless death trap:
Last week Qimikom took an 8' fall after dislodging his pedal from the fence. Just a few scuffs on the saddle.
Groceries:
