Using the principle of the torroidal transformer, primary windings are wound on an annular core, generating a magnetic flux which is completely contained in the core.
A single secondary 'winding' passes through both the first core and a second identical core, forming a chain. This chain can be repeated, ending with a conventional secondary winding on the last core.
The 'core' links would be laminated steel, while the intermediate links would be steel with a substantial copper ring, or possibly steel laminated with copper.
The chain is a single 'conductor' which requires no insulation. none of the surfaces carry any potential, so there is no risk of electrocution or short circuit. The links of the chain do not need to be in contact with each other, since each transmits power to the next by fully contained magnetic flux.
The chain could be used to safely transmit power for building equipment, power tools, underwater or in any environment where cable damage or contamination is a problem.
A broken chain would also be relatively safe. The broken surfaces would exhibit either magnetism or very low voltage AC. If you have a pacemaker, holding the broken end of a core link near to your chest would be unwise. Shorting across the broken ends of a conductor link with a metallic object would allow a large current to flow, with the assciated risk of causing a fire if there were no circuit breaker.
Both input and output terminations would need to be insulated as normal, since both would carry mains voltage to permit the device to be used as a direct replacement for an extension cable.-- Twizz, Jul 02 2010 Flexibility ?-- 8th of 7, Jul 02 2010 My immediate reaction is to think that there would be high losses in the system... If each link was effectively a transformer, with an efficiency of , say %90, then Power Out= Power In * 0.9^no of links. Even if each link is %99.5 efficient, that could make losses quite bad. (I think?!)
My second reaction is to then question the phase properties of the system.
My third reaction is "Ouch! I never did get the whole flux thing during my EEE undergrad degree..."-- Jinbish, Jul 02 2010 This does not sound compact! I favour using a laser as a method of transforing energy. There might be an efficiency loss at either end, but none in the middle, unless a bird flys through. Then you get a small loss of power and a BBQ'd bird.
What you mention is feasable and something like a single like of the chain is used in rotaty transformers to transmit power or signals to something that spins and would otherwise ware contacts out.
Transformers are, if especially well built, up to ~99.5% efficient. So after 140ish links only 50% of the power would remain. Normal commercial transformers are only usually up to 95% fficient. This would take only 13 links to leave you with 50% power. If you want more efficiency, it might work, with a combination of superconductors and magic.-- saedi, Jul 02 2010 I accept that the system will ahve some losses. I don't see why an extension cable wouldn't consist of a few short links at each and and a few much longer links in the middle, keeping the total number of links to a minimum. If it's being used to run a 1000W power tool in dangerous conditions, at 50% effeciency it's still cheaper to run than, for example, an IC powered tool.
There would be a phase shift at each stage of the chain as there would with a series of transformers, but I don't see why this would be a problem.
The purpose is to avoid having potentially dangerous energy flying about. A laser to transmit 1000W would be especially dangerous and difficult to maintain contact.-- Twizz, Jul 02 2010 Wide low energy laser beams to be concentrated at receiving ends?-- pashute, Mar 22 2011 better to simply put it in the safe and carry it.-- WcW, Mar 22 2011 random, halfbakery