Re the Aussie rooftop turbine. All the guy has done is use a VAWT and laid it on it's side so it's now a horizontal VAWT (HVAWT?).
I would imagine that it would be as efficient as a normal VAWT as long as the wind is coming perfectly at at. If it's coming a few degrees either side it will work to a point but lose efficiency quickly and stop altogether if wind hits it from the sides. Innovation is what we all strive for, but if it doesn't improve on an existing design then it's a bit pointless.
I can see his thinking that if the turbine is mounted on the roof ridge then the wind will hit the roof and move over the rooftop like a aerodynamic wind tunnel test on cars etc.
Could possibly be of use in coastal ares where the wind is perhaps more constant in direction.
I was informed by a vintage cycle parts type chap that there was a 12v dynohub made I think he said around the 1940's. He's gonna try and get me one. What a nice bloke. That would solve alot of problems.
That is correct Peter, the 12v version was introduced in 1936 and withdrawn two years later according to my 'The sturmey Archer story' book by Tony Hadland - ISBN 9507431 2 7 A good read of a great British company - they don't make 'em like they used to... It's performance (power) won't be any higher than the 6v version, as the current was rated at 0.23 amps 12x 0.23= 2.76 watts, but it should cut in at 60 rpm, as compared to 120 rpm with the 6 volt units.
Jesus!! ben id there as many as that? I was tlaking to a guy on ebay the other day who had a Dynohub for sale in America.Thing was it was in the packet and brand new.. lol Not many like that kicking around.....Seemingly he was selling S Archer dynohubs in the state and visited the company on many occasions....His emails were very interesting. HE has given me some nice High Res pics of a brand new Dynohub.
Anyone tried the geared Dynohubs? And do they have more cogging? Do they made a hell of a noise?
Ideas for Dynohub charging
