CHARGING ALONG: TOO MANY RECHARGERS
A. Michael Noll
June 22, 2015
© 2015 AMN
It seems everything we have today – smart phones, cell phones, tablets, computers, watches, toothbrushes, cameras, vacuum cleaners – have batteries that need to be recharged. I have so many chargers all over the house – and many stored away — that I no longer remember what each charges.
The chargers are also know as power supplies. But by any name, they seem to proliferate on their own – as do the appliances that require them. Good old-fashioned batteries are used less and less. Even many flashlights use rechargeable batteries, requiring yet another charger. On a trip, a bag load of chargers goes along.
The electrical engineering behind these chargers is quite basic. In some cases, it is as simple as a transformer and a few diodes. Others are a trifle more sophisticated so that they can be used on 110 or 220 volts. In standby mode, they all consume very little electric power. Unfortunately, they all look much the same – hence all the confusion. They also mostly all produce 5 volts DC, but at differing current loads. Too much is fine – too little is not. The different plugs are a problem. The chargers used for computers usually operate at higher DC voltages and can be somewhat sophisticated, sensing when the computer is fully charged and going into a standby mode.
The electrical genius Nikola Tesla envisioned some sort of energy field that would cover the planet, delivering power wherever needed. Some variation on his idea might be the solution to recharging all our devices. An electric field would be created within our homes that could be tapped for slow trickle recharging of our devices. In close proximity, electromagnetism works well for recharging. But Tesla envisioned something over a vast area – although it only needs to work within a home or business.
Perhaps I should collect billions from greedy investors – and then just charge away into oblivion to the tranquility of my own tropical paradise island – with no computers, cellphones, or anything to be recharged.
We had a brief interview with Professor Charles Steinfield before a seminar he presented on the role of information and communication technologies for development, focusing on their role in the agricultural context. Distilling key lessons learned from his field research with Professor Susan Wyche, he touches on the kinds of technologies being used, the implications of their use, and the barriers to further success. This brief overview conveys the substantive areas he addressed in more depth in the seminar that followed. See the short video at: https://vimeo.com/110827930
Professor Steinfield’s work is supported by USAID, which funds MSU’s Global Center for Food Systems Innovation (GCFSI). A copy of his report with Susan Wyche on ICTs and development is available from the GCFSI web site at http://gcfsi.isp.msu.edu.