Sony Wirelessly Powers TV, Increases Transmission Range (Video)

Oct 3, 2009
Tetsuo Nozawa, Nikkei Electronics
The demonstration of wirelessly transmitting power to a TV, which is Sony's 22-inch "KDL-22J5." Electricity was transmitted from the transmission device to the reception device right below the TV.
The demonstration of wirelessly transmitting power to a TV, which is Sony's 22-inch "KDL-22J5." Electricity was transmitted from the transmission device to the reception device right below the TV.
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A box containing a rectifier circuit, a matching circuit, a DC-DC converter circuit and so forth is attached to the back side of the TV. The power plug of the TV is connected to the box.
A box containing a rectifier circuit, a matching circuit, a DC-DC converter circuit and so forth is attached to the back side of the TV. The power plug of the TV is connected to the box.
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The demonstration of the "Repeater Device." When placed between the transmission device and the reception device, it relays magnetic resonance and turns on a light bulb.
The demonstration of the "Repeater Device." When placed between the transmission device and the reception device, it relays magnetic resonance and turns on a light bulb.
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When the Repeater Device is removed, the transmission efficiency drops at a transmission distance of 80cm. And the light bulb hardly lights up.
When the Repeater Device is removed, the transmission efficiency drops at a transmission distance of 80cm. And the light bulb hardly lights up.
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A demonstration of a toy car and an ornamental lamp. It is possible to transmit electricity from one transmission device to multiple reception devices.
A demonstration of a toy car and an ornamental lamp. It is possible to transmit electricity from one transmission device to multiple reception devices.
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Sony Corp developed a wireless power feeding system for TVs and other electronic devices.

This time, Sony prototyped a system that can transmit electric power of 60W to a TV located 50cm away. The company announced the development of its wireless power feeding system for the first time.

The feeding method is based on the magnetic resonance method, which the Massachusetts Institute of Technology (MIT) proposed in 2006. But Sony developed the "Repeater Device," which is used to increase wireless transmission range.

The new wireless power feeding system can transmit power of about 60W when the distance between the transmission device and the reception device is 50cm. In this case, the transmission efficiency between the two devices is about 80% (about 60% if the rectifier circuit is included).

The boxes of the transmission and reception devices measure 40 x 40cm (with a height of several centimeters). Though Sony did not reveal the contents of the boxes, it seems that they contain coils similar to those used for the systems developed by MIT and Intel Corp.

The Repeater Device is a passive component without a power source. It is placed between the transmission and reception devices to relay magnetic resonance. With this device, it is possible to maintain the transmission efficiency of 80% even when the distance between the transmission device and the reception device is increased from 50cm to 80cm, Sony said.

By using the wireless power feeding system, the company demonstrated the Repeater Device, a toy car mounted with a reception device with a diameter of 4 to 5cm and an ornamental lamp that is made with optical fibers and wirelessly supplied with electricity in addition to a TV.

Though Sony has not yet determined when it will be able to commercialize the technology, the company plans to apply it to a wide variety of consumer products.