This is a demo project.
Any little power is sufficient.
If nothing else works, then I will use a fan to move the Savonius rotor (I must do this indoor anyway). Or even blowing on it. :-)).
Note about my post #17: Uploading the picture to show up within the text did not work first time.
I did not experiment the posted circuit in post #17.
falexandru:
Note about my post #17: Uploading the picture to show up within the text did not work first time.I did not experiment the posted circuit in post #17.
Do you mean post #18? If you are referring to the diagram in that post, it's the "classic" Joule Thief circuit. It's pretty easy to get that working. But, it's critical to get the coil hooked up correctly. I suggest adding a capacitor across the generator [following the power switch]. The value will depend on what kind of power is involved. Such a capacitor will make it more likely that charge will accumulate and run the stored voltage up until the Joule Thief starts to oscillate. Then, it will transfer power from the capacitor, to the battery. But, as pointed out before, this will only be feasible for a low power system. But, it sounds like that's what you are after -- merely a demonstration of principle.
@reversEMF - right!
I only want to show that this way of obtaining energy is feasible using basic resources, it is easy to make, easy to maintain.
[maybe OT: so many times I saw projects (including my projects :-)) never getting to an end because of to ambitious goals. It is crystal clear in my mind that Arduino is about learning and teaching in the first place. Of course, real life projects can be done in the Arduino ecosystem (or alike), but myself I am not in this.]
Thank you for the reccomandation! It is possible to use a trimer (aka variable capacitor) for the capacitor you suggested? If so, what value do you think?
I can find here easy a 4-20 pF and a 7-100 pF.
The 7-100 pF has a larger range so might be handy. Then I can go (hopefully 
) by trial and error.
The coil- yeah, I have a bunch of torroids and drossels on my desk. I cant measure them by my multimeters and honestly the devices to measure capacitance and inductance are insanely expensive.
Please the "Quote" feature. Otherwise, it's hard to track context when reading your posts.
@ ReverseEMF - you are right!
But so far, I couldnt figure out how to quote part of the text. Quote command is picking all text, making everything even more difficult to read. I attempted to delete unwanted text or to manually quote, but the result was even more fuzzy :-(.
I will be very happy if somebody can point me to a tutorial or just tell me how to do.
++++
This is my lucky thread - I already figured out how to insert images in the text! :-))
Hi,
If you look at the tool bar across the top of the post/edit window, you will find an icon that shows "Insert a quote"
This inserts quote tags around a highlighted bit of text in your post window.
So copy and paste what you want in your post, then highlght it, then select "Remove Formatting" in the tool box, the "Ao" icon.
Then select "Insert a Quote".
You will then have your tect in a quote box.
It is worthwhile using "Remove Formatting" to take out any artifacts that the editor may misinterpret.
http://forum.arduino.cc/index.php/topic,148850.0.html
is a good read.
Tom...
So copy and paste what you want in your post, then highlght it, then select "Remove Formatting" in the tool box, the "Ao" icon.
Then select "Insert a Quote"
Thank you!
My mistake was: I selected and quoted the text directly in the quoted text, in the author's post.
PS It is any way to also automatically quote the quoted author in the same time? Thanks!
falexandru:
PS It is any way to also automatically quote the quoted author in the same time? Thanks!
Try this:
- Click on Quote [on any post -- just so you get an editing session with a automatic Quote field -- for instance, click Quote on this post]
- Way at the right end of the tool bar, there is an icon that looks like a little page of text -- it also looks grayed out but don't believe it. Click on it and it will change the editor contents into the raw text with BBCode showing.
- Find the BBCode for the Quoted area. Use that as a quide. You can leave out everything but the
author=forum_usernameattribute
Perhaps is not exactly the right place to rise this up, but I hope I will be forgiven.
There is very little - if any - info about vertical axis turbines in a manner that is appropriate for demo or diy aim.
I noticed so far two main issues with vertical axis wind turbines:
a) the available voltage is going to be far less than one of a PV panel, at a similar phisical magnitude
Perhaps this comes from the PV being industrially manufactured while turbines have to be made from scratch in most dit cases => this leads me to the idea to use a "buffer" - like a super-capacitor and then periodically discharge it through the Joule thief circuit, but under higher voltage - that is something I never saw in the internet and I would be very glad to get your opinion
b) There is a dependence of the Joule circuit to the way the inductance is made or mounted. I have no idea how to approach this, except by trial and error - any tip or no-matter-how-personal opinion would be of great help.
For the time being I am working on the PV module, but I will finish very soon and start the fight with the electronic part of this wind turbine.
The plan is to use an (close to) exhausted 1.5 V AA Alkaline pile in place of the wind turbine while desk prototyping. Alternatively, I can mount a voltage divider to the NiMH 3 or 1 units that I already coupled to the PV generator.
I built the simple Joule thief.
Parts:
- Transistor : 2N2309 - 1 pc
- Rezistor: 1 K/ 0.5 W - 1 pc
- LED: white, 5 mm - 1 pc
- torroid core, 1 cm diameter, white ferrite - 1 pc
- cables- 0.5 mm D: 2 pcs @ 30 cm each, blue and white
- minibreadboard - 1 pc
- Battery NiMH AAA, 1.2V - 1 pc (alternatively: pile AA, exhausted)
Now it comes the strange part: a slightly larger blue torroid core, of 2 cm D, 80 cm wrap same wires did not work. I went down to 40 cm wraps - no chance LED did not light.
In one example it was a picture of a blue ferrite ring - looking quite the same I used and did not work.
Searching for ferrite cores I found tons of info about a zilion types of ferrite rings but nothing clear about what the colors mean. Somewhere I found that some types have more permeability than the others, which sounds somehow trivial.
Supposing I will end up with a suitable more efficient circuit, then how I can be sure I can order the same type of ferrite cores?
Thank you very much for any tip, kind guidance or pointing to a more friendly web-site!
Somewhere I found that some types have more permeability than the others, which sounds pretty trivial.
Absolutely not!
The permeability, loss vs frequency , saturation magnetising force etc vary enormously with different materials.
Unless you know these characteristics you can't design the inductor.
I don't know the colour codes for various ferrite materials - where did you get the cores from? does the manufacturer publish data which would help?
Allan.
I fully agree.
The seller knows nothing more than the size and the color.
The Joule thief is a demo, so no critical parameters.
But still, how can I order the same ferrite cores from some other seller or from the same seller later on, if they cant tell me more than the above?
It would be wonderful to differentiate by color, at a minimum. But would that suffice?
+++
An alternative might be to use transformers in place of the torroids or to find somewhere a circuit using linear inductance. I would avoid that since it will certainly lead to more complex circuits.
falexandru:
I am trying again.I have no idea why it did not work first time. Just do not understand.
Do you know what the black dots mean, they are more important than core type/permeability ?
They mark beginning of the winding, I think you connect wires not correctly.
This is you turbine
https://www.newphysicist.com/make-vertical-axis-wind-turbine/
Yes, I've gotten away with just using toroids designed to be used as RFI filters, when making Joule Thiefs. I know very little about designing inductors, and I've had little problem getting Joule Thiefs to "work". Do they run at optimal efficiency? Who knows. When I'm doing this stuff, I'm in full-on hobbyist mode
So, like Ted said, you probably didn't get the wiring right. Just switch the wires on the primary, and try it again [or on the secondary]. I.e., make sure it's hooked up like the diagram Ted posted. Also, I've found it seems to work best when the turns ratio is 1:1. Example: if there are 10 turns on the Primary, then make sure there are 10 turns on the Secondary.
Also, it helps if the toroid is meant to to be used for RFI filters with a max current flow greater than the kind of current the Joule THief will be running at. If it's just driving a simple White LED, then we're talking around 20 to 30mA. Also, the toroid should be able to support frequencies up to a few MHz.
Now, I'm sure my more inductor savvy piers are going to jump all over me [and go ahead], but I'm just trying to give you "seat of the pants" hobbyist pointers [you know, like, "hey, this toroid that I bought from Electronic Goldmine [with no discernable parameters other than it's for making RFI filters] looks big enough for this application, lets give it a try!"
I wrap the 2 wires (blue and white) together, in the same way in the case of white ferrite and blue ferrite.
I connected the white wire of one side to the blue wire from the other side - this is the common end. Then I used the remaining wires to connect to the circuit as in the schematics.
I unwrapped and wrapped again starting opposite direction. I used grey ferrite core. I switched the ends. No way. Silent LED.
One moment I thought there is very low inductance in blue ferrite (for unknown reasons), so perhaps more winding would help.
The method is here (but it is detailed in many other web-sites)
https://www.evilmadscientist.com/2007/weekend-projects-with-bre-pettis-make-a-joule-thief/
and a more kids friendly desccription here:
http://technologytutor.co.nz/technology-and-science-for-kids/01-build-your-own-joule-thief
Show the picture
Here it is the pic:
- background: the circuit which works ok
- grey ferrite ring - which does not work (wired)
- blue ferrite ring which does not work
The length of the wires in blue and grey cases were 80 cm and then 40 cm.
The length of the wires in the white ferrite ring 30 cm.
Add 1uF capacitor parallel to resistor