Below are the 3 most recent journal entries recorded in jvs_projects' LiveJournal:

Sunday, August 19th, 2007
2:45 am	Iced Carrot Juice Coffee I was at my new job the other day reading a good 1000+  pages of SOP's trying to keep my attention, infinitely scrolling pdfs.  I find that nibbling on something while reading actually helps me to keep focus.  I was nibbling on carrots while sipping coffee and heard myself think  "hey coffee and carrots taste *good* together."   I know disgusting right?!! Well, this evening, I juiced a few carrots, brewed some java, quickly cooled it in metal pot 1/2 submerged in cold water. When the coffee hit around 60F, I added the carrot juice and it tasted great! It was about 25% carrot juice and 75% coffee. I think a 40/60 mixture would work better. I'm pretty sure the carotenes would also slow the oxidation of the Chlorogenic acid, that quickly makes brew coffee turn bitter. Well, they do call Aquarius,  "Aquarius, the unorthodox." jv Current Music: The Smiths - Strangeways Here We Come (Comment on this)
Saturday, August 18th, 2007
8:18 pm	A Universal Cell Phone Charger When I was in Germany, my cell phone died b/c I couldn't find a US->EU wall adapter for my cell phone charger. It was driving me nuts that the output of the cell phone charger was 5VDC 350mA and the USB ports everywhere in the world all output 5VDC 500mA. So when I got home, I made one from old parts you can find from a thrift store for about $1 a piece: Parts List: 1 USB 2.0 chord 1 cell phone charger with a conector that fits your phone. Solder Gun/Iron Heat Shrink tubing or other insulation. Wire cutters/strippers. Est Time 30minutes. Note: This will only work well if the output of your regular cell phone charger is close to the standard USB output namely 5VDC, 500mA. Look for the markings on the plug. If you aren't sure, don't start until you're certain. Make sure the polarity of your thrift store power supply is the same as your regular cell phone charger. You can tell by looking on the side of the power supply for little 3/4 concentric circles. It should have (+) pointing to one circle and a (-) to the other circle. These correspond to the inner and outter parts of the connector that goes into your cell phone. In nearlly all cases, the (+) will be the inner circle and the (-) will be on the outside. It's really just a matter of cutting, stripping soldering, insulating. Most phones have the smart charging circuit on the phone and not at the charger, so if it's connected to a regulated power supply (the USB is) and the voltage and current are close, it should charge the phone nicely. In almost all cases the charger output will be 5VDC, because the Lithium cell is nominal 3.7VDC and 4.20VDC when it's fully charged. So the power supply has to be slightly greater than the full charge voltage. I like to make sure everything works before I solder, so I routinely hook things up with aligator clips. You can google the USB wire color codes or check out a site like USB MAN to determine how to connect the wires. You can use just about any insulation you want, so long as it insulates. 5VDC is pretty wimpy. I use self-sticking rubber plumbers tape. It's superior to electrical tape, because it stretches and form fits to your work. jv Current Music: Dead Can Dance - American Dreaming (3 Comments |Comment on this)
Thursday, April 6th, 2006
3:17 am	Bicycle Car Horn Revision 2.0 I revised my bike car horn, mainly because 1). I didn't like the original placement of the horn (under the seat) and 2). the pack voltage (9.6vdc) was a little less than a car (12vdc). So I made a new battery pack out of 2 x 7.2vdc 3300mAH hour battery packs connected in series.[1] These batteries can deliver up to 30 amps continuously. The end result is the horn is now over-voltaged and puts out a blast at around 140db. I also cleaned up the overall appearance with a little heat shrink tubing. I placed the horn on the left front of the fork for 3 reasons: I am now behind the horn, so I don't hear it as much as the driver/pedestrian/animal in front of me. The wires are less likely to snag, because they run along the axis of the fork. Having the sound emanate from the front of my bike will help drivers better pinpoint my location (while moving) I also tested a much smaller 9.6vdc pack that has a very high maximum continuous discharge current (10C or 11amps). I found the pack in a toy at the thrift store, paid $1.50 for it. The pack only weighs about 100g compared to the 900g 14.4vdc monster. If you want to hear it, I made a little video. You can find it on my myspace video's page ( Here are some Picts: ) ( Parts List: ) ( Tools: ) ( A word on Batteries ) We ride tomorrow and test it out. :D jv [1] Eventually, the pack will also run a 24 x 2 super bright LED Array I'm working on. (Comment on this)