25 Aug
2008
25 Aug
'08
8:59 p.m.
Dan Mills, mused, then expounded:
Wireless power transmission by low frequency resonant coupling **IS** a
useful trick in some circumstances (I have seen it used to charge hand
lamps for use in explosive atmospheres for example (Well over ten years
back)), and in intels case could be used to for example power a wireless
mouse or charge a phone, but you can bet there would be a handshake
between the device and the charging pad prior to RF being applied.
About 10 yrs ago, I worked for a company that made a transponder that
mounted on the bottom of a locomotive and communicated with an RFID
r/w tag that was mounted on the sleeper between the rails.
The transponder had a low freq - 125 KHz, loop that sent power to the
tag, which woke up and converted the power to DC, approx. 15mw to power
the tag. Data communications took place at 2.4GHz. I forget if they
went to England or France, but they may still be in use today.
Bob
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