Forgot your password?
typodupeerror
This discussion has been archived. No new comments can be posted.

OccupySF IT Admins Using Pedal Power For Protest

Comments Filter:
  • by Hartree (191324)

    I think I'd get hold of a small camp generator. They're small, pretty cheap and very quiet. Someone might even loan or donate one.

    But, I guess that doesn't have the suffering for your cause appeal of pedaling a hacked up bike generator.

    Given the food conversion efficiencies, fuel used in production, transport fuel usage for getting it to the city, the mentioned conversion inefficiency, etc. how carbon neutral that all is compared to just saying screw it and buying a little gasoline.

    • by wierd_w (1375923)

      The problem is that this is SF. There are emmissions control laws against such petrol generators. Many inhabitants don't even have petrol powered lawn mowers. Many even use old fashioned mechanical push powered rotary mowers, due to the taxes on owning gas mowers.

      Generators would be hard to own in SF

      • A quick google search sure shows a lot of generator rental and sales places in San Francisco proper.

        Must not be that hard to own.

      • by j_sp_r (656354)

        Why just not get an electric mower?

  • I would propose purchasing a couple of solar panels to do the same job. It may be a little bit more expensive, but not by much - PV prices have completely collapsed this year. Granted the solar panels won't work after dark...
    • No kidding. They're already going far too long without showers. Why make things worse?

      Harbor Freight has a 45 watt solar kit for $180. Just add a battery and an auto adapter for your laptop and you're good to go. That'd be plenty for my little i7 notebook and charge a few phones even if I was sitting there all day playing FarmVille. And probably store enough power to run a 4G hotspot thru the night.

      And this part really gets me:

      However, one bright spark managed to cobble together a new converter that downstepped the 12 volt supply directly to five volts much more efficiently, using mail-order parts and a bit of ingenuity.

      What mail-order parts? They could go to any electronics store in the area (

  • Really.... (Score:4, Insightful)

    by Lumpy (12016) on Friday October 14, 2011 @09:22PM (#37720856) Homepage

    "The group were having to run a 12 volt supply, convert it to 150 AC and then back down to five volts for phones and the portable radios used to maintain emergency contact."

    Glad to see that there are NO electronics engineers or other people that have a clue as to what they are doing.

    12V run into inverters to make 120VAC (not the 150AC the writer failed to fact check) and then using wall chargers for the devices. Nobody had a fricking car charger for their phone? This is getting utterly comical.

    I am glad to see this because it means in the SHTF situation, most of the populace will die horribly because they are far too uneducated about basics of life so they will pedal 40% more than they need to to make up for the power losses because they cant be bothered to think through what they are doing.

    get some basic education people. learn about electricity, you fricking use it every day.

    • They have 12V -> usb converters in the dollar store here in Vancouver. Each $1 unit provides 2 USB sockets ..one is 1Amp the other is 0.5amp. Then all you need is a 3 head Accessory splitter from Radio Shack (whatever they're now called), and you can charge 6 cell phones at once.

      Another potential solution is to have someone park a car nearby and keep it running with a 20foot extension cord attached to the accessory plug. Put a car battery at the other end for when they have to drive away and you ha

      • by jamesh (87723)

        The expensive part is buying the 50foot extension cord and loping it's ends off.

        The other expensive part is keeping a car idling for a long period of time...

        • by dynamo52 (890601)
          Most expensive of all however would be th impoud fees. If you park on Market they'll tow your car in minutes even if there isn't a demonstration going on.
    • Re:Really.... (Score:5, Informative)

      by subreality (157447) on Friday October 14, 2011 @09:47PM (#37721004)

      Bizarrely, the double conversion might be more efficient than a car charger. Car chargers are often just linear regulators, which means they're dropping 12v to 5v by dumping the difference to heat. They're only about 40% efficient.

      An inverter is usually 80-90% efficient. AC switchmode power supplies (which is what USB wall-warts are) are 80-90% efficient. That's about 65-80% efficient, full-cycle. The inverter won't do well at low-load, but if they have a half-dozen wall warts on a plugstrip, they'll do better than your average car charger.

      People recombining technologies to make a new thing isn't bad. From a philosophical standpoint, electrical engineers are doing the same thing - they're just recombining slightly lower-level technologies. Sure, a 12v-5v DC-DC converter will do better, but is it really worth the extra engineering effort when you already have the necessary higher-level components to build something that works?

      • by Co0Ps (1539395)
        Great points. Mod parent up.
      • Re:Really.... (Score:5, Informative)

        by Anonymous Coward on Friday October 14, 2011 @10:35PM (#37721316)

        i've taken apart about 20 no-name car chargers now. linear regulators are too expensive, too much dissapted heat means you need expensive metal to make a heatsink. counter-intuitively, switching regulator designs are cheaper to produce. they are almost all based on the mc30463 or equivalent circuit.

        • I've taken apart a couple and found nothing but a LM7805 and a couple caps. It runs hot as hell, but it puts out 500ma without melting.

          But you're right, many of the better ones have at least a basic buck converter.

      • by houghi (78078)

        but is it really worth the extra engineering effort

        Yes. That is how new things are invented and made.

        • I completely agree with that being a worthwhile thing to do, but what I really meant was whether it was if the present problem was big enough to be worth the investment of time. For this problem? Probably not. But if it was me, I'd do it anyway, because I enjoy doing and learning.

    • Re:Really.... (Score:5, Insightful)

      by Solandri (704621) on Friday October 14, 2011 @10:04PM (#37721108)

      Glad to see that there are NO electronics engineers or other people that have a clue as to what they are doing.

      Two paragraphs after the one you quoted from TFA: "However, one bright spark managed to cobble together a new converter that downstepped the 12 volt supply directly to five volts much more efficiently, using mail-order parts and a bit of ingenuity."

      The other problem with stepping 12V DC down to 5V is that often, the only charger people have for their phone is the proprietary AC one. The industry has standardized on mini/micro USB lately, but most older phones will only charge with an AC adapter. And almost nobody will be willing to chop up their laptop's AC adapter plug to be able to hook it up to straight DC. So the universal power supply remains 120/240 V AC.

      I do have to wonder though, given this report is from San Francisco and the type of people drawn to OWS, why hasn't anyone thought to set up a windmill or some sort of solar array (about 4-5 m^2 @ 0.15 capacity factor should generate as much power as people taking turns cycling 24/7). PV solar sucks in comparison to other electricity sources, but it's forte is off-the-grid applications like this.

      • Indeed. I've been off-grid at various times, and my ace in the hole is a 2x2 solar panel with alligator clips charging a 12v automotive jumpstart box that had a built-in inverter. Charge it all day, power the laptop and charge the phone all night.

        • by drinkypoo (153816)

          My ace in the hole is a 45W harbor freight system... enough to run a netbook and my WISP connection via POE injector :D

      • I do have to wonder though, given this report is from San Francisco and the type of people drawn to OWS, why hasn't anyone thought to set up a windmill or some sort of solar array (about 4-5 m^2 @ 0.15 capacity factor should generate as much power as people taking turns cycling 24/7). PV solar sucks in comparison to other electricity sources, but it's forte is off-the-grid applications like this.

        The bike generator was donated, how much would such a solar panel cost? Plus, with a bike generator, the protesters don't have to leave in order to get an exercise it's a win-win situation. :)

      • by tlhIngan (30335)

        And almost nobody will be willing to chop up their laptop's AC adapter plug to be able to hook it up to straight DC

        .

        Won't work for a lot of laptops - they draw so much power that unless the want lots of current flowing through the DC lead, they often use higher voltages. 16V, 18V, 20V+ are fairly common voltages.

        (Modern laptops can easily require 75W, 130W, 200+W of power. We're talking of 6-10+A in the DC lead...).

      • by ukemike (956477)

        I do have to wonder though, given this report is from San Francisco and the type of people drawn to OWS, why hasn't anyone thought to set up a windmill or some sort of solar array (about 4-5 m^2 @ 0.15 capacity factor should generate as much power as people taking turns cycling 24/7). PV solar sucks in comparison to other electricity sources, but it's forte is off-the-grid applications like this.

        Because the cops come through and confiscate everything and throw it in the trash, so using expensive stuff is risky. The other day the police took a bunch of stuff from the OccupySF group and threw it in the garbage. The sanitation folks returned it to the protestors saying "we're in the 99% too."

    • by dbIII (701233)
      When you duct tape stuff together with what you've got then that's what happens.
      I get your point about pointless waste of energy through needless steps of conversion though. I'm still amazed at the number of people that have solar on their roof, battery storage, have the time to plan things and still have full mains power lighting. My dad had 12V lighting for a complete house in 1959 and the technology has moved on a bit since then guys. Then of course there's photovoltaics to run air conditioning. WTF?
  • Other options... (Score:5, Interesting)

    by benjamindees (441808) on Friday October 14, 2011 @09:26PM (#37720884) Homepage

    Probably the easiest and most sustainable setup would be to convert a port-a-potty into a biogas digester, and use it to run a small gas genset or even a thermoelectric generator. Of course that would make something of a target for police.

    Some motorcycles or scooters have alternators, that can be used for battery charging. Or if size is an issue, there's always a small generator like the Honda EX350 that can be had for around $200.

    • But then we would have to like buy gas from big oil, man...
    • I think the easiest and most sustainable* setup is to simply get a bunch of deep cycle batteries and charge them from the mains. 1 human pedaling is maybe 50 watts if they're in average shape. 1 100 amp-hour 12-volt lead acid battery is 1200 watt-hours... Which is an entire 24-hour day's worth of pedaling.

      They're set if someone can bring in a half-dozen batteries once a week by station wagon or hand dolly. But this isn't about practical. The bike is more fun and/or attention-getting.

      * In any sense: I d

  • by Anonymous Coward on Friday October 14, 2011 @09:43PM (#37720984)

    I know this is /. but did anyone read the article? The second page is ridiculous.

    “We’d love to get an Apple, because a lot of the software we’re used to is on the Mac,” What software does a protest need other than maybe a web browser to organize and spread your message? Where are all of these people's computers? I'm guessing sitting at home because they don't want to have it broken, stolen or lost...

    Then they continue on to make a cellular hotspot or an android phone sound like complicated network infrastructure being managed by the protestors...

    • by billcopc (196330)

      Video editing apps so they can post to Youtube... That's my first guess.

      Frankly, they could probably do JUST FINE uploading cell-phone videos and having a friend offsite to edit/caption/comment and whatnot.

  • I saw minutes of a meeting being typed on computer and projected on white sheet w/computer and projector getting power from an exercise bike rig

  • Several friends have exercise bikes that provide magnetic resistance. Basically, most of the hardware for the making of a dynamo/generator is inside, right? These things are pretty expensive already, so it wouldn't cost much more to make that energy actually usable - as in, you could feed it back into the grid just by plugging in your exercise bike into a socket. Then an app would keep track of how many megawatt hours you generated with your own muscles - an extra source of motivation!

    But what would reall

The most important early product on the way to developing a good product is an imperfect version.

Working...