Mike AA1TJ has sent me an interesting letter about using thermoelectric modules to generate a few milliwatts of power from body heat. This got me thinking about the other ways of "harvesting" free energy from vibration, movement, heat, mains hum fog, RF from radio stations etc. One bizarre idea from a few years back was a leg-brace that powered a mobile phone by leg movement (see left). There are ICs coming onto the market that scavenge energy from various sources allowing low powered devices to be powered for free. The challenge for us QRPers is to think of creative new ways to generate a few milliwatts to get signals across oceans. Who will be the first to work DX using RF rectified "off-air" from the local FM radio or TV transmitter?
Showing posts with label harvested. Show all posts
Showing posts with label harvested. Show all posts
14 Apr 2010
Free power transmitters
Mike AA1TJ has sent me an interesting letter about using thermoelectric modules to generate a few milliwatts of power from body heat. This got me thinking about the other ways of "harvesting" free energy from vibration, movement, heat, mains hum fog, RF from radio stations etc. One bizarre idea from a few years back was a leg-brace that powered a mobile phone by leg movement (see left). There are ICs coming onto the market that scavenge energy from various sources allowing low powered devices to be powered for free. The challenge for us QRPers is to think of creative new ways to generate a few milliwatts to get signals across oceans. Who will be the first to work DX using RF rectified "off-air" from the local FM radio or TV transmitter?
23 Oct 2009
EPAD FETs and low voltage TX
This application note shows a 32uW oscillator using EPAD FETs that works with 0.5V supply and may be useful for "harvested energy" TX circuits. The ALD110800 FETs used has also been used to power an amplifier with just a 0.2V supply.
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