3W free space charger has 30m range
The PowerSpot works at up to 30m for over-the-air-charging of multiple devices without special locations, mats, or line of sight.
The transmitter uses the 915-MHz ISM band to send RF energy to a tiny Powercast receiver chip embedded in a device, which converts it to direct current (DC) to directly power or recharge that device’s batteries.
It uses direct sequence spread spectrum (DSSS) modulation for power and amplitude shift keying (ASK) modulation for data, and includes an integrated 6dBi directional antenna with a 70-degree beam pattern. Powercast did not indicate how efficient the charging procedure is but said it will begin production now that it is FCC approved and is also offering a PowerSpot subassembly that consumer goods manufacturers can integrate into their own products.
Powercast expects up to 30 devices left in the zone on a countertop or desktop overnight can charge by morning, sharing the transmitter’s three-watt (EIRP) power output. Charging rates will vary with distance, type and power consumption of a device. Power-hungry, heavily used devices like game controllers, smart watches, fitness bands, hearing aids, ear buds, or headphones charge best up to two feet away; keyboards and mice up to six feet away; TV remotes and smart cards up to 10 feet away; and low-power devices like home automation sensors (window breakage, temperature) up to 80 feet away.
PowerSpot measures 7.3 inch by 2.1 inch by 1.4 inch. Production units are expected in 3Q18 for about $100 from distributors Arrow Electronics and Mouser Electronics. Once PowerSpot reaches mass production, Powercast projects a $50 ASP from major electronics stores or from consumer electronics manufacturers offering it as a charging option.
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