Small genset
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From: D Yuniskis on 3 Feb 2010 17:27 Joerg wrote: >>>>> D Yuniskis wrote: >>>>>> I want to hack together a *small* "hand powered" genset that >>>>>> I can use to charge a 12V GelCel to power a SW rig when I am >>>>>> in the field. >>>>>> >>>>>> I should be able to use a DC PM motor with a suitable >>>>>> gearbox and crank. Any suggestions as to how to go about >>>>>> spec'ing the motor for such an application? I figure I >>>>>> should be able to easily generate 20-30W "mechanically" >>>>>> without resorting to "pedal power" >>>>> >>>>> Your arms are gonna fall off, real quick, at 20-30W. >>>>> How long do you figure you'll have to crank the thing? >>>> >>>> I don't expect to need to generate 20+W. Rather, I think >>>> *sizing* for that will put the "sweet spot" of the genset in >>>> a more comfortable ergonomic operating point. >>>> >>>> I think the rig uses about 5-6W during Rx. Tx obviously is >>>> the killer :> But, that's what you have a battery for :> >>>> (i.e., store the power you are generating for those times >>>> when you key the rig). >>>> >>>> Even at 20W, I think it is doable for "reasonable" stretches >>>> provided you have enough mechanical advantage. E.g., a short >>>> crank will kill you a lot quicker than a long one. >>> >>> Well, better start doing push-ups. You goal should be 200 in one >>> stretch :-) >>> >>> Or get a kayak and plough it through the lake at full bore, every >>> day, rain or shine. >> >> No, my upper body exercise of choice is cutting down trees and >> digging out the root balls. Four 50'+ in the past year. The hole >> I dug to remove the root ball for the last one took 7 tons of >> topsoil to fill (*after* removing the stump to a depth of 4 ft... >> no idea where the damn soil sneaks off to! :< ). > > Wow! Ok, I take everything back, you must be in top shape. I did split a > lot of firewood but it's been a while and I probably won't be able to > compete. It's amazing how much more tiring this sort of thing is than walking (I walk at a brisk pace... 4 miles in under an hour)! And, with the very low humidity here, you don't have the usual "drenched in perspiration" cues to let you know you are pushing yourself harder than it *feels* (until, of course, you get light headed -- a cheap high? :> -- and the attendant headache from dehydration :< ) > When I was younger I could have competed. Torqued off a 16mm-thread > crane hook at a company ... screeeee ... *POCK* ... thoroughly impressed > the guys that an electronics jockey could do this. <grin> No "competition". Rather, a simple acknowledgement that I'm getting older and if I don't invest time in keeping "fit", there are serious health consequences. :< >> Though I suspect this also places demands on lower body (lifting >> the soil out of the hole) -- hard to figure out just what portion >> of the work is done where (though your shoulders sure ache after >> one of these "events"!). Of course, walking 25+ miles every >> week helps keep the lower body "well oiled"! :> > > Same here, I spend a lot more on sports shoes than on car tires. But 25 > miles/week ain't that much. No, but finding more *time* is the hard part. By the time you count getting dressed to go, it's almost an hour a day (well, my goal is an hour a day which would be 28 miles/week... but, I invariably miss a day ;> ). I have not been able to find anything *else* that can be done *while* walking so it appears (superficially, at least) to be "a big waste of time". :< >> Putting 6W into a battery for 10 minutes will be a piece of cake! > > Yes, now I believe it. Maybe put a li'l solar panel on top to cheat a > bit :-) I thought about that. But: 1) doesn't work at night 2) big and bulky (I looked into trying to design some sort of a "folding" array but the hardware to support the panels weighs more than just carrying another *battery*!) Maybe when the flexible panels become affordable...
From: Joel Koltner on 3 Feb 2010 17:52 "D Yuniskis" <not.going.to.be(a)seen.com> wrote in message news:hkcslh$buq$1(a)speranza.aioe.org... > I have not been able to find > anything *else* that can be done *while* walking so it appears > (superficially, at least) to be "a big waste of time". :< Listen to your favorite music, podcasts, books on tape, etc.?
From: D Yuniskis on 3 Feb 2010 18:29 Joel Koltner wrote: > "D Yuniskis" <not.going.to.be(a)seen.com> wrote in message > news:hkcslh$buq$1(a)speranza.aioe.org... >> I have not been able to find >> anything *else* that can be done *while* walking so it appears >> (superficially, at least) to be "a big waste of time". :< > > Listen to your favorite music, podcasts, books on tape, etc.? Music. But I can do that while *working* (or any other activity). I don't process technical information aurally so the latter two options don't work. I've tried carrying a PDA and "taking notes" but the damn thing bounces around too much while I am walking (and trying to focus on it means I'm not watching where I am walking -- I've walked into low tree limbs too often! :< ) So, just "walk faster" and get it over with quicker! :>
From: Joerg on 3 Feb 2010 18:24 D Yuniskis wrote: > Joel Koltner wrote: >> "D Yuniskis" <not.going.to.be(a)seen.com> wrote in message >> news:hkcslh$buq$1(a)speranza.aioe.org... >>> I have not been able to find >>> anything *else* that can be done *while* walking so it appears >>> (superficially, at least) to be "a big waste of time". :< >> >> Listen to your favorite music, podcasts, books on tape, etc.? > > Music. But I can do that while *working* (or any other activity). > I don't process technical information aurally so the latter two > options don't work. > > I've tried carrying a PDA and "taking notes" but the damn thing > bounces around too much while I am walking (and trying to > focus on it means I'm not watching where I am walking -- I've > walked into low tree limbs too often! :< ) > > So, just "walk faster" and get it over with quicker! :> Joel and I have a condition that _requires_ daily excursions by hoofing it: We have large dogs. If they don't get their walk my wife and I have to contend with three cranky and contentious companions all evening ;-) All I have to do is don the running shoes and off we go. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Michael A. Terrell on 3 Feb 2010 20:31
D Yuniskis wrote: > > Hi Michael, > > Michael A. Terrell wrote: > > D Yuniskis wrote: > >> Yeah, I started looking through my "collection". Unfortunately, > >> the ones with dead batteries are the "toys" that were ineffective > >> hence they were unused and batteries left to die. > > > > I have a couple junk drills and one motor from a new drill that > > someone broke the output shaft of the gearbox. It is from a 18 volt > > drill. I am going to gut the 14.4 volt drill battery packs and add a 20 > > foot cord with a cigarette lighter plug so I can use them with one of > > those 12 volt lead acid 'jump packs' made to start a car with a dead > > battery. I already use one with a portable DVD player to watch old > > movies. > > You might find this "won't work" :> (I can't say for sure) > I tried doing this many years ago with a battery pack from > a cordless Gardner Denver WW gun. I was only using a *short* > length of wire and the IR drops in the cable were unreasonable. > (of course, I think the battery was a much lower voltage... > I'm not sure of the details). > > Point is: test this before you invest lots of time and effort > so you don't find yourself disappointed. (also test under load) > > >> There is some advantage to a *non-dead* battery as then the > >> battery storage is implicitly taken care of (though the batteries > >> on cordless drills tend to be on the small side :< ) > >> > >> <shrug> I will have to play some more... > > > > Have you ever seen the hand crank generators made for military > > radios, in W.W. II? AKA: a 'Gibson Girl' radio. > > http://www.wftw.nl/gibsongirl/gg113.jpg > > Yes, this was what I had in mind for packaging. I think > the genset for that radio was pretty puny, though. Akin > to these hand cranked "emergency radio/flashlight/foot massagers" > they sell nowadays (how many t's in "toy"?) > > Hmmm... even if I don't *gut* the "good" drills, maybe I can > still use them to empirically derive some information regarding > power (and V and I) available for a given "rated" motor... How about modifying one of those wind up flashlights? A pair is only $7.99. <http://www.harborfreight.com/cpi/ctaf/displayitem.taf?itemnumber=65207&Submit=Go> It would be a cheap way to test your idea, and it already has a case. :) -- Greed is the root of all eBay. |