# There goes the neighborhood

#### Billy10mm

Oct 31, 2012
13

My quick background. Have always been a bit of a tinkerer. Mostly in automotive repair and other mechanically-driven hobbies (like firearms - which explains my username). Used to take my electronic toys apart when I was a kid, but lacked parents who would enable any learning on that front in the form of books, kits, etc. Unfortunately got stuck with a string of blow-hards for science teachers throughout grade-school, and never made it to college - so little to no learning there either. That said, I've always retained interest in electronics.

Anyway, a little storm blew my way two days ago and left me without power for about 22 hours and although I had a fully charged cell phone when the power went out, it was almost dead 15 hours later when I stuck it on the car charger and that was from simply coordinating with bosses/underlings and reading work emails.

At work yesterday, I tried to find a portable USB-based charging device that would charge cell phones off of regular off-the-shelf batteries (which I have plenty of and have great shelf-life), and upon finding there weren't many good off-the-shelf solutions - have opted to finally take the plunge and build my own.

I mean seriously, why pay $40 off-the-shelf or$20 for a pre-made kit when I can spend $150 on parts and multimeters and get the experience of destroying all of my parts and likely my iPhone as well Anyway, I'm a total noob at all of this save for some small soldering I've done, poorly, in the past. Main parts for this project are already ordered from Mouser (along with some cool USB female panel-mount connectors from L-Com) and I'll be doing quite a bit of light-reading from the Tutorials section in the upcoming weeks. But wanted to introduce myself and say hello. Hello. --Billy #### shrtrnd Jan 15, 2010 3,826 A brave soul who wants to do for himself, instead of having others do it for him. You're very welcome here, as most of us suffer the same syndrome. Don't hesitate to drop a question or two here on your project, there are some very smart do-it-yourselfers here. We welcome your arrival here. Good luck with the project. #### donkey Feb 26, 2011 1,301 hi and welcome. I am curious as to what you will build here. I am a north qld boy (australia) and get really shocked to see how many people don't have back up plans for things like storms. If you want help or just a few bad ideas that I have come up with over the last few years for disaster planning then feel free to ask me #### CocaCola Apr 7, 2012 3,635 I mean seriously, why pay$40 off-the-shelf or $20 for a pre-made kit when I can spend$150 on parts and multimeters and get the experience of destroying all of my parts and likely my iPhone as well

A car to USB adapter for about $2... An 8 cell or two 4 cell battery holders about$5-7...

Total Cost about $7-9 I'm lazy in my old age most of the time... Welcome to the forum, yeah it's fun to DIY, but I like being practical with the hobby as well... #### Billy10mm Oct 31, 2012 13 hi and welcome. I am curious as to what you will build here. I am a north qld boy (australia) and get really shocked to see how many people don't have back up plans for things like storms. If you want help or just a few bad ideas that I have come up with over the last few years for disaster planning then feel free to ask me I wouldn't say that I didn't have a backup plan. We had two vehicles full of gas, plenty of food, water, clothes, candles, flashlights, batteries for flashlights, and games to play. What I had forgotten about was my ability to charge my work phone regularly. I have car adapters for all of my phones so in a pinch, I could have just made a phone call from my car. But I ended up using a lot of power between texts and emails to co-workers - and more than anything else, I'm using that as an excuse to fund this little expedition This will be a real simple project: 9v battery 9v battery holder Led toggle on/off switch (not necessary but cool nonetheless) USB type A female connector for the output (all of our phones can be charged via USB) 5v regulator to drop the voltage to USB spec Diode to keep the phone from charging the battery That's the plan. I've seen something very similar on Youtube in my travels, mine will hopefully look a lot nicer, especially if I can get mine packaged into a big Altoids tin which we'll know once I get the parts in and mock it all up. --Billy #### CocaCola Apr 7, 2012 3,635 FYI you won't get far with a 9V battery, you would be much better off with C or D cells... #### Billy10mm Oct 31, 2012 13 FYI you won't get far with a 9V battery, you would be much better off with C or D cells... From the reports I've seen, a 3Gs (my model of iPhone) will go from totally dead to about 60% full on average from a generic 9v Duracell. Two Duracell's to charge up my iPhone is fine by me as I have 20 or so on hand and next time around I'll stock up a few more. I thought about C or D's but at 1.5v, I would have to string at least 4 of them together (5 would be better) to get the required voltage or have to up-volt it which is beyond my admittedly moronic-level of comprehension. That many C or D cells would clearly violate my "trying to fit this into an Altoid's tin or something only slightly bigger" goal. --Billy #### CocaCola Apr 7, 2012 3,635 #### Billy10mm Oct 31, 2012 13 If you stick with the 9V consider using a switching regulator over the linear for less waste... http://www.dimensionengineering.com/products/de-sw050 Oooh. This is very cool. I'm losing a minimum of 2 watts, more likely closer to 4, to heat - so this looks quite promising. I've already got the 5w linear regulator on order (was going to use the tin itself as the heat-sink) - I think I'll play with that first and then play with your switching regulator. Cool stuff, thank you much for your help. --Billy #### donkey Feb 26, 2011 1,301 on the other side if you want to save money on batteries I have seen hand crank items http://www.jaycar.com.au/productView.asp?ID=ST3352 this one I like cos its at 5v, has radio and flashlight too. carrying one item to replace a few and no extra batteries. ticks a few boxes for my survival kit. having said that though I still use a few other things for backup #### Billy10mm Oct 31, 2012 13 on the other side if you want to save money on batteries I have seen hand crank items http://www.jaycar.com.au/productView.asp?ID=ST3352 this one I like cos its at 5v, has radio and flashlight too. carrying one item to replace a few and no extra batteries. ticks a few boxes for my survival kit. having said that though I still use a few other things for backup My wife and I have an LED flashlight that has a crank, we got it as a gift a few years ago and we've used it a few times, it works well for quickly finding things or walking from room to room. Unfortunately, the cranking phone chargers get rather poor reviews. Many complain that it doesn't actually charge unless you're actively cranking it. With a charge time of around 1.5 hours on my phone, that simply too much effort for me. #### donkey Feb 26, 2011 1,301 yeah hand crank items have a bad rep, but they come in useful if you get one with the right battery backup and gear ratio. the one that has interested me is so hard to find but was seen on tv a few years ago. you and a wind up spring like in clocks, as it unwound over several hours it produced the current required to power a radio. using this, the right gear ratio and storage you could find yourself a really good dynamo for phones #### Raven Luni Oct 15, 2011 798 yeah hand crank items have a bad rep They can leave you feeling a bit crankey Theres also the magnetic shaky things which use induction. I've also seen toroidal ones that work well with minimum effort if you get a good oscillation / spin going. #### (*steve*) ##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator Jan 21, 2010 25,505 There's also exercise bikes. As a kid I had one that actually moved as well. It generated power. At the time I didn't have a phone to charge though. Hope the neighbourhood is coming back online for you. #### donkey Feb 26, 2011 1,301 Theres also the magnetic shaky things which use induction. I've also seen toroidal ones that work well with minimum effort if you get a good oscillation / spin going. I have seen these, the problem is the magnet, they are getting more expensive. but you can still make one for under$50 and buy one for about \$40

as for excerise bikes... I have a running joke with a friend who is a primary school teacher, put the kids on giant mouse wheels and hook them up to alternators, its great excercise and good clean green electricity..... lol

#### Billy10mm

Oct 31, 2012
13
Quick update. Finally got some self-time today to sit down and work on this. The original switch I had bought turned out to be slightly too big (after trimming the case down to try to get it to fit). My local Radio Shack has very little that I can need/can-use, but I found another Radio Shack 5 minutes farther down the road that all kinds of cool goodies including Arduinos, books, Helping Hands, and the trays were full with all kinds of good little components. Anyway, I picked up a switch that will work a little better (size), a 5mm panel-mount led, some heat-shrink tubing, and some wire (though I went too thick on the gauge).

Wired up my 9v battery holder to the switch and then on to the 5v regulator I have. Flicked the switch and I'm getting exactly 5v which is great, but 10 seconds later I smell something. I tap the regulator with my finger and WHOAH, heat. Plug the temp sensor into my mutimeter, and touch it to the regulator - 217 degrees fahrenheit. Ouch, I knew I'd be bleeding some heat, but didn't realize it'd be this much this fast.

Guess I'm going to order up that switching regulator immediately and with any luck I'll have this thing up and running next weekend.

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