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  • Author Author: aemarconnet
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Wireless power Challenge: Excited, Honored, i can't wait!

aemarconnet

Hi everyone,

My name is Alex Marconnet and i am one of the very lucky Element14 members who's idea was selected for this road-test/competition. I am very grateful to Element14, Texas Instruments and Würth Elektronik for providing me with this opportunity.

I have not yet received the unit, but i am looking forward to the competition. I thought that i would share part of my application:

"

Hello,

 

My name is Alex Marconnet. I know you have many applications to consider, but i hope that you will take a look at my attached sketches and consider my application as i am very eager to partake in this road test.

 

Wireless charging technology is something that i have been interested in for some time. I was so eager to implement it into my own life that i hacked a palm-pre "touchstone" charger into my Samsung phone because Samsung took too long to release the feature. Although i studied as a Mechanical engineer during my university days i have always had a strong interest in and pursuance of Electrical engineering.

 

Whenever i look at the current applications for wireless charging technology, and it seems that the majority of applications are very highly specialized (basically phone charging).  When i started brainstorming i kept coming up with more highly specialized applications (i.e. Trickle charging car batteries, and firefighting apparatus). But then it struck me that many devices we use daily could be improved by a wireless upgrade. In a home there are dozens of devices that use batteries for power but have very low power requirements. One example i illustrated (Wireless-charged mouse) is the desktop mouse which uses only coulombs of power per hour of active use. By replacing the batteries in such a device with a inductively charged capacitor, we could eliminate the consumption of batteries by these devices. charging for a matter of seconds could power such a device for hours. Unlike re-chargeable batteries, a capacitor will never "wear out"

 

I would propose a system that would bring Qi chargers into every room of the house. Place a aesthetically pleasing charger on a coffee table and replace the TV's remote with this system. Enjoying a movie? Toss your phone on the same pad to charge it.

 

For this road test i would like to work on a more universal application of the technology. I have done some [very] rough calculations with off-the-shelf components and i believe it would be very possible to maintain the form factor of a pair of AA batteries. Please look at the attached "wireless capacitor - battery replacement concept.jpg".

 

Thank you for your consideration.

Best regards,

Alex Marconnet

"

 

 

below is a snapshot of my initial concept...I envisioned a "stick on" charging coil, a pair of off-the-shelf capacitors, and a small charging / voltage converter...I know that this is a lot to pack into the space, but I am hoping that a prototype comes close. I will admit my vision stems from the form factor of the Palm pre charging coil and circuit which I hacked into my Galaxy S3 phone. I expect the coil in this kit to be more substantial because it is capable of coupling more energy than the palm pre "touchstone". I was planning on breadboarding the circuit and getting it to run, then figuring out the specifics of cramming it into that "AA" form-factor, I will probably end up 3D-Pringing the final battery-imitation enclosure. I will do my best to fit it all in! I welcome any advice that the community has to offer.

 

image

 

 

 

Here is a shot of my sketchbook with some of my original brainstorming ideas...

 

 

          image



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  • Nice idea!

    In the previous challenge I made something to charge 4-6 AA batteries, and had the added handicap of having to boost the output current. I'm curious how you will be doing, and whether you'll be able to accomplish your goals! The receiver coil is quite large compared to the AA batteries...

    I saw your 'back of a napkin calculations', and wondered  how you got to the numbers... If want to charge until 3.3V, and drain until 2.7 you can use 3.3-2.7/3.6 of capacity, and the rest of the energy is unusable... That's the bad part of capacitors, as you can only use part of the charge to power your circuit... Or you would have to use an energy harvesting converter to fully drain the capacitors!

  • in reply to vsluiter

    Thanks VSluiter,

     

    I really appreciate your input. I just received my kit a day or two ago and have only just begun to start working with it. I am excited with the operational rage. Unlike other wireless charging kits, this one is capable of running the 5W load at over an inch away or approximately a 40º angle. The main coil on the driver is very thick, but it seems that Element14 is willing to give out some of the other thickness's.

     

    To answer your question:

     

    It has been a while since my university courses, but i did anticipate the drainage problem. When i neatened up my sketch for my submission, i fear that i failed to clearly illustrate it. Each of the capacitors i was looking to use is about 3/4 the length of a AA. I was hoping to squeeze a capacitor charging circuit into the left-over area of one and squeeze a small DC-DC output voltage converter into the other. I know that TI makes some very small and highly efficient voltage converting solutions, and i was hoping to find one for my application.

     

    I am now working on trying to identify just how small i can make both circuits, and thus determine if the original capacitor i had looked at would work.The numbers i showed were very much "back-of-the-napkin", there will be in-efficiencies and i know i cannot harvest every last drop of power. But even so, if i could get a solution working that can power my mouse for 30 minutes and a 1 minute charge time (half my idealistic calculation), i would be proud of my novel little concept. I intended to hide the charging coil within a 2-3mm thick hard-plastic mouse pad. Let's say that i pull off around 30 minutes of life and about 1 minute of charge. That is a duty cycle of roughly 3.5 percent. Personally, i return my mouse to center 90% of the time it would likely spend far more than the required 3.3%duty cycle on the charger anyway.


    Thinking down the road: I might like to play with the coil options and perhaps build my own (or multiple) into the mouse pad. It would be really nice if i could have an oversize mouse pad ~6in by 9in and charge my phone at the same time.

Comment
  • in reply to vsluiter

    Thanks VSluiter,

     

    I really appreciate your input. I just received my kit a day or two ago and have only just begun to start working with it. I am excited with the operational rage. Unlike other wireless charging kits, this one is capable of running the 5W load at over an inch away or approximately a 40º angle. The main coil on the driver is very thick, but it seems that Element14 is willing to give out some of the other thickness's.

     

    To answer your question:

     

    It has been a while since my university courses, but i did anticipate the drainage problem. When i neatened up my sketch for my submission, i fear that i failed to clearly illustrate it. Each of the capacitors i was looking to use is about 3/4 the length of a AA. I was hoping to squeeze a capacitor charging circuit into the left-over area of one and squeeze a small DC-DC output voltage converter into the other. I know that TI makes some very small and highly efficient voltage converting solutions, and i was hoping to find one for my application.

     

    I am now working on trying to identify just how small i can make both circuits, and thus determine if the original capacitor i had looked at would work.The numbers i showed were very much "back-of-the-napkin", there will be in-efficiencies and i know i cannot harvest every last drop of power. But even so, if i could get a solution working that can power my mouse for 30 minutes and a 1 minute charge time (half my idealistic calculation), i would be proud of my novel little concept. I intended to hide the charging coil within a 2-3mm thick hard-plastic mouse pad. Let's say that i pull off around 30 minutes of life and about 1 minute of charge. That is a duty cycle of roughly 3.5 percent. Personally, i return my mouse to center 90% of the time it would likely spend far more than the required 3.3%duty cycle on the charger anyway.


    Thinking down the road: I might like to play with the coil options and perhaps build my own (or multiple) into the mouse pad. It would be really nice if i could have an oversize mouse pad ~6in by 9in and charge my phone at the same time.

Children
  • in reply to aemarconnet

    Alex

    It is a nice idea that has applications for other items.

     

    I'd suggest that you concentrate on the 'proof of concept', then try to get the size reduction for the working solution.

     

    The mouse mat idea will work great.

    My wife had to use a mouse for her laptop, and with no fixed desk had issues with the mouse mat, so my son knocked up a wooden base and screwed the mat it to the base.

    Your thick plastic one would be similar and serve a useful purpose as well.

     

    Mark

  • in reply to mcb1

    Thanks Mark,

     

    i definitely agree that i need to get a proof-of-concept bread boarded with some leads running into a mouse before i try to pack it all in or i will end up in a design loop!

     

    Good luck

    -Alex