| Author |
 Topic  |
|
Victor
Junior Member
United Kingdom
409 Posts |
 Posted - 28/08/2007 : 20:14:11
|
I know the dynohub is not the most powerfull of wind turbine Generators,but I now wondering if it is a better idea to make 2 turbines charging individual batteries of 6 Volts.This should allow me to get superb current into the batteries at a lower voltage.
Charging the batteries in a 12 volt system I think the Dynohub is not really up to it unless you use a voltage doubler circuit which adds to the resistance of the circuit and cuts down the Current too....
(Possibly)
I currently have 2 Dynohubs and 2 brand spanking newNovotec ehd-1 Dynohubs.....
I think the Novotechs will give me more power,but they have more of a cogging effect...
My dynohubs turn perfectly you see in a small wind as I have stripped them both down and cleaned them. There is a vast improvement in performance and even i the slightest wind they are turning and giving me a good result in power....
It`s really down to a decision of 1 or 2 things now.
1 - Run 2 novotechs at 12Volts giving superb power output in high winds.
2 - Run the 2 Dynoub Turbines in lower winds on 1 6 volt battery per turbine.
Any ideas into this will be much appretiated.
Regards
Vic..
|
|
|
ll81
Junior Member
124 Posts |
Posted - 28/08/2007 : 21:29:44
|
Run one to each 6v battery. If you need 12v you can series connect the batteries but still leave one hub for each battery.
woo-hoo |
 |
|
|
Del
Junior Member
United Kingdom
369 Posts |
Posted - 28/08/2007 : 22:01:58
|
Hi Victor,
Have you got two 6 volt batteries?
Classic cars like the old MGB used to use two six volters (under the back seat if I remember correctly) but that's an automotive battery designed for short bursts of power.
You're right if you use a voltage doubling circuit - you would halve the amps (ohms law).
If you decide to run the novotechs you can always look to counter the cogging effect by using torquier blades or simply add more blades, so if you're using a 3 blade set up go for 4 or five.
Cheers
Del. |
|
|
|
Gill
Starting Member
Australia
42 Posts |
Posted - 29/08/2007 : 05:15:58
|
G'day Victor,
Why not series the two gens? A circuit has already been posted.
A double pole, double throw switch could be added to run them in series on breezy days then switched over to parallel on windy days. No need for added expense on 2 x 6V batteries.
Cheers... Gill |
|
|
|
BushWhacker
Junior Member
Canada
325 Posts |
Posted - 29/08/2007 : 06:24:16
|
Hi Victor,
You wrote "My dynohubs turn perfectly you see in a small wind as I have stripped them both down and cleaned them."
I just thought I'd drop a tip, "Hoppes teflon powder"
http://www.wileyoutdoorsports.com/Detail.cfm?ID=826
I'm not saying to buy there, it was just the first website I found that carries the product. If the metal parts inside your dynohub are worn in clean them with a product like Brake Kleen ( Comes in a aerosol can and smells like dry cleaning fluid, available at auto parts stores). When they are dry, dust them lightly with Hoppes Teflon Powder. (That little tiny container should last for years) and run them without any other lube (read: NO OIL!)
The reduction in friction is HUGE!
DO NOT use this on parts that are not broke/worn in as it will take forever for them to wear in properly.
I just finished building a soap box racer for my neighbors son today and he ran it down my front street (a slight hill). I was not amused. I got my little bottle of powdered Teflon out, and dusted the wheels and axles (bolts and lawn mower wheels, functioning as plain bearings) and his speed picked up by about 30% on his third or fourth run after that.
I swear by Hoppes Teflon powder. What it does to the action on a gun is unbelievable.
Cheers!
BW
BTW I don't work for or sell any Hoppes product. I just like things that work.
Everything should be made as simple as possible, but not one bit simpler. - Albert Einstein |
|
|
|
BushWhacker
Junior Member
Canada
325 Posts |
Posted - 29/08/2007 : 06:30:54
|
Also can anyone *cough* II81 *cough* draw up some kind of schematic to show how you can charge two six volt batteries separately and draw twelve volts from the pair at the same time? I've thought about this and have no idea of how to do it. (unless it's so simple I dismissed it???)
Thanks,
BW
Your resident electrical idiot.
Everything should be made as simple as possible, but not one bit simpler. - Albert Einstein |
|
|
|
Del
Junior Member
United Kingdom
369 Posts |
Posted - 29/08/2007 : 08:54:53
|
Morning all,
I'm with you on the electrics BW.
Gill - could you show us a diagram please?
Cheers
Del. |
|
|
|
ll81
Junior Member
124 Posts |
Posted - 29/08/2007 : 10:57:26
|
If you series run the hubs as they are AC will only get maximum voltage when they are both in phase, as they spin at different speeds off different turbines it won't be that often. If you parallel them when they are out of phase you will just be shorting them out against eachother. This way you will always get maximum voltage. Thinking about it you could ditch the two batteries and replace with one but but at low wind speed unless both hubs are at the peak of the voltage output you will not charge. This way works best.
woo-hoo |
Edited by - ll81 on 29/08/2007 10:59:04 |
|
|
|
Gill
Starting Member
Australia
42 Posts |
Posted - 29/08/2007 : 13:13:44
|
G'day Dell & fellas,
My suggested circuit:
The out of synchronization is elevated by the capacitors, and I disagree that only one charging source can be connected to a battery.
Cheers... Gill |
Edited by - Gill on 29/08/2007 13:22:49 |
|
|
|
ll81
Junior Member
124 Posts |
Posted - 29/08/2007 : 14:14:23
|
I like the idea Gill. I take it you connected the caps like that to stop wasting leakage current in series mode.
I'm not sure if it's something I wrote got misunderstood but as many charging sources as wanted can be connected to a single battery. If it is in regards to the parallel charging I meant direct coupling at AC. If each genny has it's own BR then yes they can be paralleld
Also worth pointing out if series running gennys the current must pass through both. If one is turning slower than the other then it will waste power as it will try and spin the slower one. If one of the gennys is at the 0v point then the current through it is being wasted purely in I2R losses.
Why do I never spot bad spelling till after I've submitted my reply??
woo-hoo |
Edited by - ll81 on 29/08/2007 14:18:20 |
|
|
|
fungus
Moderator
297 Posts |
Posted - 29/08/2007 : 16:39:31
|
I would only really series the hubs if they are on the same generator/shaft, anh would rectify to DC first.... A switch would be the best charging 2 6v batts in parallel and seriesing them with the switch, I wouldnt charge the batteries separately as they might not charge equally and get 'out of synch'.
A schematic for a series/parallel switch with a 3PDT switch:
 |
Edited by - fungus on 29/08/2007 18:14:23 |
|
|
|
ll81
Junior Member
124 Posts |
Posted - 29/08/2007 : 19:04:41
|
Good point fungus. Thing is when they are like that you can only charge or consume not do both together (if only charging at 6v). I think the best one would be like I showed but check the battery voltage ocassionaly. If one is always found to be lower than the other then put a switch in that allows the batteries to be fed from the opposite genny. If there is no pattern as to which one gets more charge then your way would be better. I would dare say it will be found that there wouldn't be much difference, I think the best way is to obviously try and find out.
woo-hoo |
|
|
|
Del
Junior Member
United Kingdom
369 Posts |
Posted - 29/08/2007 : 20:25:46
|
Dear ll81, Fungus & Gill,
You're obviously electrical and electronic wizards as when you guys start discussing eveyone else goes quiet.
I won't pretent to understand much of what you have debated over the last few messages above but after having read it a few times and scratched myself I think I've got about a 75% understanding now. I must commend Gill on her (gosh I hope I've got it right and you're a her Gill) notepad drawing. I found it very clear to follow so thank you for remembering us lesser beings.
Cheers
Del.
|
|
|
|
gotwind
Forum Admin
United Kingdom
932 Posts |
Posted - 29/08/2007 : 22:26:58
|
Hi Guys - I've been working late.
Good discussion.
I am 100% certain 'Gill' is a bloke 
I have never met a female wind energy enthusiast, so far.....
Maybe in the future
The Futures Green - Getwind of it. |
|
|
|
Del
Junior Member
United Kingdom
369 Posts |
Posted - 30/08/2007 : 00:10:22
|
Oh bugger,
So sorry mate. Hope you wern't offended.
Cheers
Del.
PS. If there's a female 'guest' reading this then register just to be the first gotwind lady! |
|
|
|
BushWhacker
Junior Member
Canada
325 Posts |
Posted - 30/08/2007 : 01:51:06
|
My thanks to Gill as well, you made that so simple even I could understand it! (It's printed and in my shop notes) I thought I was in trouble because I intend on going with DC gen units and wondered what the heck I'd need rectifiers for???? Then I caught your little note on the bottom right. *sigh of relief*
Fungus and ll81, In the past I had to wire a DPDT On/Off/On (3 position?) normally off switch, to reverse polarity powering a linear actuator. Couldn't something similar be done to switch the + power from two DC gen units to the opposite battery using a 2 position (On/On) switch and use a common - ground?
Another silly question... All I know about diodes is that they are to electricity, what a check valve is to water. Do they come in different sizes (voltage or current ratings)? If so, if you use one that is too large for the application (over rated) is there any electrical losses or danger of fire etc. or only the loss of some coin from your pocket?
The reason I'm pursuing this is I could get a lower turbine charge speed (6.5 or 7 volts VS. 13 volts) when wind charging my trailer (caravan) batteries. I hope this makes sense to you.
I don't recall for sure, but think that in England you use a positive ground on your cars. Please correct me if I am wrong. In North America a negative ground is the standard.
This is great for Del, myself, and I'm sure a few lurkers. It's like going to school with the perfect tuition price.
Thank you all!
BW
Everything should be made as simple as possible, but not one bit simpler. - Albert Einstein |
|
|
|
Topic |
|
Ideas for Dynohub charging
