Mojo Mobility's induction charging tech: best thing to happen to discs since Tron
By Tim Stevens 
posted November 13th 2008 10:19AM
posted November 13th 2008 10:19AM
We are absolutely, completely ready for wireless induction charging to make it big. Have you seen our gadget charging station? It's like some Lovecraftian nightmare; our latest intern went over to plug in his BlackBerry two days ago and we haven't seen him since. For years we've been getting teased with limited, proprietary solutions (mostly for sweaty videogame controllers) but we seem to be firmly and disappointingly locked in the competing standards phase. While we hate to see yet another contestant enter the fray, Mojo Mobility Inc. might just have a winner with its Near Field Power technique, relying on thin, inexpensive coiled discs to both send and receive up to 4 watts of power with 70 percent efficiency. Unlike the competition no exposed contacts are required, and while it looks like you'll still need to place the device onto a charging pad, with multiple transmission discs that pad could charge all your gadgets at once. Mojo plans to supply the receiving discs to battery and device manufacturers in the near future, and to that we can only say hurry up. Think of the interns!
What happens if you pee on the pad?
It charges your pee.
You break it.
I think we need to contact a Urineologist.
what happens when you pee on a magnet?
You get a prize, probaly a darwin award
doesn't anyone remember the the wise words of ren and stimpy... don't whiz on the electric fence.
test
What happens?? Unhappiness!
Seriously, I want one of those to charge my iphone and an extra-large version to put in the garage to charge the electric car that I don't have.
That's just what I was thinking! A larger version of this would be ideal for EV's and probably not that hard to set up for parking garages or EV parking spaces.
4 watts of power with 70% eff.....
Isn't that just 2.8 watts? Any EEs here?
still 4 watts, just more joules are used to charge something that would be, say 95% efficient. so, it may take longer and/or use more kw/h on your power bill.
I'm pretty sure they mean charge up to 4 watts, meaning it's using 5.7? and 70% of that is equal to ~4
Or nevermind then :P
Well, you're both right
The actual power is 2,8 Watt (the power you could use for charging), but the device draws 4 Watt from the electrical company meaning that in the long run, this will be pretty costly if it's on all the time.
70% isn't that good ...
still, not bad when you consider the transfer medium is basically non-existent, and (if i remember correctly) 10g copper wire is something like 95% efficient at 1M length, and looses 2% for every gauge size smaller. have to wikipedia that, can't remember the exact numbers.
With an efficiency of up to 70% and a deliverable range of 2.5W - 4W this unit would draw 3.6W - 5.7W assuming the efficiency is constant (which it may not be).
EMoShunz:
You would be GREATLY inaccurate about your figures for copper wire conductivity.
Besides, there's no % figure for copper wire, even if you specify the diameter as you did. It then would have a fixed resistance. But at high voltages or low currents, the power loss within the cable would be insignificant. This is classic Westinghouse versus Edison stuff!
http://en.wikipedia.org/wiki/American_Wire_Gauge
Let's pick 10AWG as you say. That's 3.277Ohms/km. Thus at 1M the resistance would be 3.277mOhms. At 4W (delivered) at 5V (like USB), That would be (4/5*0.003277) or 0.0026216V drop, for a total transmission loss of 0.05%, or an efficiency of 99.95%. Even at 24AWG, the drop loss would only be 28x higher, for a loss of 1.4%, an efficiency of 98.6%.
And of course, at 12V, the power loss would go down by a factor of 5 at both voltages.
@LS2LS7:
that looks more correct, apparently about 2 decimal places off of what i remembered from the text book oh so long ago.
still 4 watts, just more joules are used to charge something that would be, say 95% efficient. so, it may take longer and/or use more kw/h on your power bill.
ignore... meant to reply to dan above.
i was an intern once.....*shudders*
oooh mini hard drives.. is this the prize in my box of cereal?
I want to see this stuff implimented in dry wall so you could your TV and not have any wires to worry about. You could stick a light on the wall anywhere and you could get rid of electrical sockets and just tap into the power on the wall where ever you needed it. No more need for spliters and other funky stuff to add clutter. Electrical cords can be shorter too sicne it won't have to be ran to the closest socket, just to the nearest wall.
Another thing you could do is have desk or desk covers with this built in and then you could have mice and keyboards that are wireless and never need to be recharged. There are so many possibilites that I wish someone would just bring it to the market so I can start doing some DIY stuff.
Too inefficient, too expensive and at the amount of power sent out to run a light, you'd run the risk of screwing up devices nearby.
This technology has been used by Wacom for twenty years for their batteryless pen input pads.
Smart DIYers have played with this technology for quite some time.
http://www.afrotechmods.com/cheap/arnoldpad/arnoldpad.htm
we'll probably end up having 15 different charging pads for all our devices...
That's what I was thinking too... Trading a bad situation for a worse one.
Seems like things are getting better anyways, with many gadgets charging/powering via mini-USB. I love not having to plug my external drives into the wall, and being able to charge my phone, BT headset, PSP, Dualshock 3, etc... all via one type of cable that I have dangling from my computers.
I really couldn't give a shit about a "charging pad" at 70% efficiency - what a total waste.
Saw this at the Fresh event at Retail Vision last spring. The charger is approximately as efficient as your wall charger, but has the benefit of being "intelligent". It shuts off when the battery is charged, unlike your wall chargers. It is also scalable to larger devices, so who knows, perhaps someday a Mojo mat in your garage to charge your electric vehicle, or a mat built into special parking spaces?
Not trying to be a real nerd here, but Tesla's wireless electricity is where this conversation needs to go. Why even charge, when you just have power wirelessly?!
Tesla's History with it, post about MIT's Project ....
That'd be MUCH cooler and very MUCH the way of the future ... mind you like Psychology advances, it took 100 years to get to even THIS point with MIT's units.
Wait, psychology advances? Is this some sort of plot to use mind control? Excuse me while I got get my aluminum foil hat (yes aluminum. That tin crap ain't worth nuthin' but a bag o' hurt)
All this for 50¢
what a deal.
Hey just think you significant others vibrator will always be ready to go.
I have evaluated this tech. The total efficiency is 70% (power out to device vs. power in to charger base) at the max. rated power. That is comparable to the best regular wall plug charger at the same power levels. See:
http://www1.eere.energy.gov/buildings/appliance_standards/residential/pdfs/bceps_slides.pdf
Also, the output power is max. 4 W which is enough for basically any handset, camera, etc. so charging time is the same as a plugged charger.
The MIT experiment is great if you don't mind a 24" diameter coil and a huge expensive box to drive it. Also, try not to stand in front of it unles you like sticking your head in microwave ovens.
How hard is it to put a device on a holder really? Do we really need this, it only makes sense if it works over a large surface, which it does not, or a large range, which is does not either.
While I'm commenting: how come your old landline wireless handsets charge when you simply put them on their holder, but most cellphones need you to connect a silly plug, how hard is it to make 2 or 3 simple metal contact on the edge.
I think everyone is missing a very crucial aspect - range. I might as well just plug it in if I have to put it on a pad. I tend to agree with Wwhat and Jeff.