Cellular phones can charge from a USB port which supplies 5 v dc at about 1 amp. That is only 5 Watts so a crank-up device seems quite feasible. To put that into perspective for machinists, one horse power equates to about 750 Watts. Your body can put out about 125 W or more so you wind up a spring with your energy and it gets converted to the electrical energy later on to charge up the battery.
Another "power perspective": my main hobby is ham radio (for 50 years this year) and I can communicate directly (no cell sites
) across much of the globe using a transmitter that puts out only a few Watts.
Best Regards, Pete
Well, yes and no.
Its kinda the difference between theory and practice.
A design engineer can dream something up and tell me what a piece of equipment
should do, but as an operating engineer I can tell him what it
will do.
To use the example of the crank up cell phone charger, I have a friend who subscribes to the " prepper" mentality. He's got all sorts of crank up radios, light, chargers and assorted what nots.
Quite proud of himself actually and tends to laugh at me sometimes when I tell him my simple military survival training and some basic items will do me just fine if needed (I have advanced aircrew survival and escape training so its just a little bit more than I tell him). He has to move out with truckloads of stuff and sneers at my thoughts of all I need is good clothes, a good knife, means for making fire, some 550 chord (some snare wire too) and water purification stuff. If I'm so inclined I'll chuck a small cheap am/FM radio in a pocket.
One day he's going one about he'll be able to crank charge his cell phone if needed. He proceeds to try and charge his cell phone. 15 mins later he's sweating like a pig and not one bit of change in the cell phone battery. Just not enough poop in the stuff he's using. The problem is that while they may run a cheap am radio or an led flashlight, they just don't have the jam to make a significant difference to a cell phone.
Cant see a spring device being any better. Probably worse as the spring in a handheld device can only store so much energy until it need to be "recharged"
Oh, that couple watts you use to talk around the world isn't exactly all that going on (which you know since you're a ham). Those couple watts go to a local repeater which bumps it up and fires it to the network of repeaters. Without that power, a couple watts is only going miles in the single (
maybe double) digits.
Unless you're talking AM and you happen to catch skip. My 12 watts of CB has gotten as far away as Ireland before on a good night. That's pretty cool.
Or, if you live back in the Ozark woods somewhere and are operating any one of the number of mega watt AM/CB stations.....we've all heard those guys (if you mess with radio at all that is). I swear, I don't know how those guys don't give themselves cancer or make themselves sterile....
