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Hi Folks,
Im just getting into the idea of making my own wind turbine.
I notice on the F&P windmill description, the wires get run down the centre of the pole tower. Are there slip rings in the system somewhere? Otherwise arent the wires from the Gen going to get twisted once they are attached to something at the bottom?
cheers
Andrew
RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495
Posted: 10:27am 30 Jul 2006
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Quick analysis of the wind direction every 10 seconds for the last errr... nearly 5 months...
So, over that 5 months, the maximum "windup" of the mill would have been 16 turns anticlockwise. As at now, it would be 1 turn anticlockwise (ie, it's nearly wound itself back straight!)
(I have sliprings, but over a 9 metre tower, I think the cable would handle 16 turns without any great problem)
As you can see, it's spent a lot of time sitting doing nothing over the last few months :(
Still, 363 hrs @ 13.8KMH should have turned in at least 90 kilowatt hours of "free" energy so far (probably much more since power returned at higher wind speeds is much better than averaging would suggest)
brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548
Posted: 10:41pm 30 Jul 2006
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Andrew, Slip rings are fine if you want to build them ,I'd make them out of 10mm wedding rings of 75mm copper water pipe epoxy set on the rotating hub with copper/carbon brushes(starter motor type)
Just drill the pop rivets out of the brush holders and re mount them somehow.
Mine works well,but ,I ,ve used ordinary brushes and they offer too much resistance..
Ross, just love that gismo thing you monitor the conditions with --can I get a pcb for building one ,or ,better still, can I buy one in kit form?
Do u have to have your computer one 24/7 for that info to be collected or does the little "onboard" chip store it for some time ?
Is this the new fangled thingybob that Gismo has developed?
BruceBushboy
RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495
Posted: 03:25am 31 Jul 2006
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Bruce, sadly its not something I can practically just give you a kit for. Well, I suppose I could actually... it'd need some tweeking though.
In short, this particular one is a WX-200 weatherstation, but because I live in an off-grid house, power is an issue. I don't have enough spare watt-hours to run big computers here - we have 5 laptops that run 24/7, but all the "real" computing is done down the bottom of the hill over a microwave radio link.
Up here though, "on the hill", all my RS232 stuff plugs into an 8-port Lantronix "terminal server". This basically converts each RS232 device so it "looks" like a TCP/IP port.
I've written software that runs on a couple of my unix boxes "down the hill" that connects to various things up here (security system, weather, C-bus, inverter, genset, touchscreen etc etc) and watches/controls/logs stuff.
The weather data is logged every minute, but wind data (speed and direction) every 10 seconds.
The "analysis" script you saw before simply parses each 10 second sample and keeps track of which way the mill would be pointing and how far that is in total rotation from some arbitary starting point. Where there has been a period without wind and it starts back up again from a different direction, the code works out which way it would probably have moved (eg, if it was an easterly wind that stopped and started an hour later from south, it would figure the mill only had to turn 90 degrees clockwise and would not have turned the 270 degrees anticlockwise.
The histogram is purely totaling 10-second intervals based on the speed, and displaying the cumulative seconds (converted to hours) in each speed bracket, and the amount of "useful" wind is based on my observations of wind speed Vs "useful" output.
Data is stored to hard disk, so I can easily go back and extract wind from any particular year/month/day/hour/minute and process it for whatever I'm interested in at the time.
I have a much better weatherstation, but it's not available to the public, and it's 3Km away so I don't use it for this analysis.
(If you're interested, http://weather.albury.net.au/ is some of the weather data, and http://skycam.albury.net.au/ is the view from here looking south. My office is just below and just left of centre, about 3.5Km away)
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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