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Forum Index : Windmills : A Windmill in an Expo
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elrastita Newbie Joined: 04/06/2012 Location: ArgentinaPosts: 4 |
Hi everybody!!! I wish to introduce myself... i'm Alejandro, from Argentina. I have been doing somethings with windmill stuff (specially with the Hugg Piggott design) and reading this forum, but this is my first time writing here!. First at all, i want to say thanks to the crew of this forum, is wonderfull!!. As i wrote at the subjet, i was asked to put a windmill in an expo... just to show it, and to be there, it has to spin but its not necesary to use the power it produce. My first attempt was to install the kit completely.. but then i thought, which things can i take out, keeping the original idea. For example, i dont need the inverter, and i dont need to charge a battery. I need at least a pair of battery (my mill works in 24v), the resistance... but does i need the charge regulator??. How do you think i must wire it with this config???.... Thanks to everybody!! keep spinning!! |
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Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Hi elrastita Welcome to the forum. If you can keep a close eye on the battery voltage, and manualy switch in a dump load ( could be extra light bulbs as part of the display ), then you could leave out the charge controller. How long does the expo go for? Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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elrastita Newbie Joined: 04/06/2012 Location: ArgentinaPosts: 4 |
oh! thanks you very much for a so fast response! i must leave the windmill for at least 3 months... and i must leave it alone!. i think the most prudent will be to use a charge controller, but perhaps we can find another cheaper idea!. thanks again! |
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Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
In that case you have no choice but to use a charge controller. If its just there for show, and you dont need it to generate any power, you could just short it out? That way it will only spin slowly, not make any power, but still attract attention. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166 |
I have not had a go at this myself but I think it would work (and look like it was running). the windmill could be run directly connected to a diversion load. the trick would be to set the resistance of the load to mimic battery voltage you are trying to replicate. diversion loads are made from nichrome wire. Seeing as this is a DIY site I should point out that almost everything that electrically heats around the house has nichrome wire in it. dishwashers, ovens, grills, stovetop coils, kettles, bar heaters, water heaters, hairdryers, floor heating cable, toasters..... you get the picture. There is a number of downsides to these heating elements. The first is the wires ability to handle high amps, most of these elements have coiled wire in them, this fits a long element in a small space but halves the wires current capacity compared to straightened wire. Secondly the resistance will be far higher than what is needed, so a number of wires or elements will need to be wired in parallel to get down to the resistance needed. I would guess that if a stovetop coiled element is 26 Ohms, then about eight of them in parallel would give us roughly 3.2 Ohms. That would be pretty close to the mark. I am not sure how many amps this would handle, I'm a bit tired to work it out tonight. I am thinking that a diversion load could be hooked to each phase then to a common point or the rectifiers can be left in and the load could be run as DC. There is pros and cons to each. It would need to be dry and well ventilated to dissipate the heat and prevent any electrolysis (rust). food for thought, Yahoo. P.S. still need the shutdown switch in the circuit.....and an amp-meter so you can see the turbine generating. Note: Some modern space heaters have a special wire that goes very high resistance at a specific temperature as a safety feature, this is not suitable as a diversion load. I'm confused, no wait... maybe I'm not... |
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fillm Guru Joined: 10/02/2007 Location: AustraliaPosts: 730 |
I would think having a diversion load direct connected may heavily load the blades and to get out of stall will require a fair blow to get things going depending on what type of blades you have , so the mill will only be turning very very slowly most of the time which is probably not very good for the visual appearance of a wind turbine, this is much the same as diversion load control of a mill once the batts have reached voltage to then stall the mill. If that was the method you wanted to use then 4 s/s probes on the AC in a bucket of salty water will do the same and you would not need a rectifier but the result will be the same but would handle the high voltage and amps if the wind gets up. Buy increasing the salinity or how much of the probes are in the fluid will vary the load , SEE HERE for a bit more info . Sourcing a cheap voltage control and a couple of batts is probably the best way to demonstrate what a wind gen can do and what is needed to allow it to work as Glenn has already said.. PhillM ...Oz Wind Engineering..Wind Turbine Kits 500W - 5000W ~ F&P Dual Kits ~ GOE222Blades- Voltage Control Parts ------- Tower kits |
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Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
I would connect it up to a battery and use a conventional load dump that progressively switched in more and more 24 volt lamps as the voltage increases. Set the voltage threshold so the first lamp just comes on at around battery float voltage, and any additional charging will progressively light up some of the lamps. The battery should be happy with that, and it would be a fully functional demonstration. Cheers, Tony. |
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fillm Guru Joined: 10/02/2007 Location: AustraliaPosts: 730 |
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yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166 |
Could just let it run open circuit, if it is not to big. A small mill on a low tower that furls early will survive most things. There is a 5 footer around here with broken slip rings, it has been merrily spinning away for 12 months waiting for some tender loving care. I'm confused, no wait... maybe I'm not... |
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Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Are you talking about multipul "Load Controlers" all set at different set points or one controller that can switch in many small loads as voltage increases , if so , I would be interested as to where you get such a beast. I would build it myself using one of those LM3914 bar graph integrated circuits and some power transistors or relays to switch the lamp loads. These are designed to progressively light up a row of ten LEDs as the dc input voltage varies up and down between two set voltage levels. Someone has probably done this before, and it may already be commercially available somewhere, others here might know. Cheers, Tony. |
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fillm Guru Joined: 10/02/2007 Location: AustraliaPosts: 730 |
A quick search bought up this LINK , there was also a good disscussion that Commanda did HERE . Not really a quick simple solution to this problem for here but interesting concept all the same . PhillM ...Oz Wind Engineering..Wind Turbine Kits 500W - 5000W ~ F&P Dual Kits ~ GOE222Blades- Voltage Control Parts ------- Tower kits |
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