UHF Power Harvesting

January 29, 2009 by Eliot 15 Comments

hdpowerharvesting

[Alanson Sample] and [Joshua R. Smith] have been experimenting with wireless power transfer for their sensing platform. Their microcontroller of choice is the MSP430, which we used on our e-paper clock. They chose it specifically for its ability to work with low voltages and they discus its specific behavior at different voltages. The first portion of their paper uses a UHF RFID reader to transmit to the sensor’s four stage charge pump. They added a supercap to provide enough power for 24 hours of logging while the node isn’t near a reader. For the second half of the paper, they use a UHF antenna designed for digital TV with the same circuit and pointed it at a television tower ~4.1km away. It had an open circuit voltage of 5.0V and 0.7V across an 8KOhm load, which works out to be 60uW of power. They connected this to the AAA battery terminals of the thermometer/hygrometer pictured above. It worked without issue. The thermometer’s draw on a lab power supply was 25uA at 1.5V.

It’s an interesting approach to powering devices. Do you have an application that needs something like this? For more on wireless power, checkout this earlier post on scratch building RFID tags.

[via DVICE]

Intel 4004 Internals

January 9, 2009 by Eliot 15 Comments

The silicon wizards at Flylogic have certainly posted an interesting chip this time around. The Intel 4004 was the first widely used microprocessor. The logic gates are much larger than you’d find in modern chips. The unique feature is that each gate is designed to make the most efficient use of the silicon instead of the standardized shapes you find now. They’ve uploaded a full image of the chip.

For an introduction to silicon hacking, we reccomend [bunnie]’s talk from Toorcon and [Karsten]’s talk from 24C3. You can find many more posts on the topic in our silicon tag.

24 Core Ikea Cluster

April 23, 2008 by Will O'Brien 43 Comments

[Janne] does freelance animation and wanted something with a bit more CPU to get his rendering jobs done. He picked up an Ikea ‘Helmer’ cabinet and refitted it to hold six Intel quad cores, six Gigabyte motherboards with 8GB of ram each and six 400 watt power supplies. He seems happy with it – I think it just needs some custom power wiring and an integrated Gig-E switch to achieve perfection. What? I’m not jealous at all.