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Topic: Wind turbine Savonious Charger based on Joule Thief - advise for a charger? (Read 4156 times) previous topic - next topic

ted

To answer your question you need to look at oscilloscope, If motor capacitor does not help you need a bigger motor.

 try bigger   capacitor.

falexandru

OK, I will mount my (portable) ossciloscope to motor terminals (cap added) and  spin the rotor by hair dryer.

I also got my brushless motor today. But I need to make a circuit (6 Schottkys is the simpliest I could find) to milk DC out if it, as far as I know. 

ted


ReverseEMF

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.
You might have better luck with magnet wire, and with smaller toroids [so the windings are closer together, and more compact]. 

Also, [referring to another post] on those motors/generators you said "don't work", did you attach a meter to them to see if they are outputting anything [and whether your getting AC or DC]?

And whenever you say "it didn't work", I think, what does that mean.  Why do I think that? Because, I don't know for sure if your aware of the concept of "a multitude of variables".  It would be more informative if, instead of saying "doesn't work", you told us what the "failure mode" is.  Even if it seems obvious or redundant.  For instance, when you were trying the various cores [toroids], did you just hook it up, then decide it wasn't working if the LED didn't glow, or did you try reversing the wires on the primary [or secondary] to give it another try...then, even after that, did you check to make sure the power source was adequate/functioning/consistent -- i.e. with the goal of limiting variables as much as possible.  And, in case you don't know what I mean by variables: The power source is a variable [in fact power source voltage is a variable, power source consistency is a variable, power source current capability is a variable], proper inductor hookup is a variable, LED polarity is a variable [i.e. is the LED connected properly].  If any if these variables are not consistent -- if more than one fail at a time, and if those failures are not consistent, then you can easily be misled.

One example of limiting variables is to use a Bench Power Supply when doing something like, testing Toroid Cores to see if they "work" or not.  A bench power supply is far more likely to be consistent, than, say, a motor being used as a generator.  Test the toroids with the bench supply, with parameters set to as closely model the real world power source [whatever that winds up being], as possible, then, when you have a set of cores that worked with the Bench Supply, you can have more confidence that if, when you try them with the real world power source, when they fail, it has more to do with the real world source. 

Another example: when trying different power sources, use the same Joule Thief setup, each time.

If you try to "save time" by testing a bunch of things at once, when things don't work, it's hard to be sure what the source of the failure is.
"It's a big galaxy, Mr. Scott"

Please DON'T Private Message to me, what should be part of the Public Conversation -- especially if it's to correct a mistake, or contradict a statement!  Let it ALL hang out!!

falexandru

@ReverseEMF

Thank you! You are right!

I guess is the time to plug in my power supply and to use a more consistent vocabulary to a more detailed description.

 

polymorph

Unfortunately, the OlyMEGA forum is currently down for upgrades. I took apart a bunch of old CFLs and scavenged toroids out of them, and wrote up with pictures how to properly phase the coils.

The dots are for transformer phasing. With a bifilar winding such as you have there (ie, the two wires are twisted together), the matching ends will have the dots on them. Basically, when an AC signal is on the positive half going in, the same end of the secondary will also be on the positive half.

From your picture, you have the windings connected correctly.

http://slideplayer.com/slide/236620/
Steve Greenfield AE7HD
Drawing Schematics: tinyurl.com/23mo9pf - tinyurl.com/o97ysyx - https://tinyurl.com/Technote8
Multitasking: forum.arduino.cc/index.php?topic=223286.0
gammon.com.au/blink - gammon.com.au/serial - gammon.com.au/interrupts

polymorph

BTW, toroids meant for reducing RFI are intentionally very lossy.
Steve Greenfield AE7HD
Drawing Schematics: tinyurl.com/23mo9pf - tinyurl.com/o97ysyx - https://tinyurl.com/Technote8
Multitasking: forum.arduino.cc/index.php?topic=223286.0
gammon.com.au/blink - gammon.com.au/serial - gammon.com.au/interrupts

ted

intentionally very lossy.
How come ?
The idea of the toroid is keep energy inside = no energy transmitting out, compare to ferrite rod.

polymorph

Ferrites meant to prevent or reduce RFI do a better job if they absorb RF energy.

Also, if it isn't lossy, the inductor formed by this will resonate at some frequencies, not a good thing if you are trying to reduce RFI. The lossy ferrite core decreases resonant peaks

I should say that NOT ALL ferrite beads and toroids for reducing RFI are lossy, but many are.

https://www.allaboutcircuits.com/technical-articles/clean-power-for-every-ic-part-3-understanding-ferrite-beads/

Quote
Noise In, Heat Out
Recall that ideal inductors and capacitors do not dissipate any energy; they merely store energy, either in a magnetic field (inductors) or an electric field (capacitors). A resistor, on the other hand, takes energy out of the circuit and dissipates it as heat. Ferrite beads, unlike inductors, are intentionally resistive at high frequencies. This is why the above plot has the red dotted line labeled "R"--from about 100 MHz to 1 GHz, the bead exhibits significant resistive impedance, not reactive impedance. Actually, some ferrite beads and ferrite-core inductors are almost identical in construction, except that the ferrite bead uses a more "lossy" ferrite material because the manufacturer wants the bead to dissipate rather than store high-frequency energy.

But why belabor this point? We belabor for two reasons. First, you cannot truly understand a ferrite bead until you have adequately pondered this fundamental distinction between an inductor and a bead. Second, this "lossy" characteristic makes the ferrite bead especially suitable for noise suppression. Why? Inductance can lead to resonance and ringing when high-frequency noise energy stored in the inductor interacts with capacitance elsewhere in the circuit. As we saw in the previous articles, ringing can become seriously problematic even when we are dealing only with parasitic inductance. We don't want to exacerbate the resonance/ringing situation, and thus we opt for ferrite beads over inductors.


Steve Greenfield AE7HD
Drawing Schematics: tinyurl.com/23mo9pf - tinyurl.com/o97ysyx - https://tinyurl.com/Technote8
Multitasking: forum.arduino.cc/index.php?topic=223286.0
gammon.com.au/blink - gammon.com.au/serial - gammon.com.au/interrupts

polymorph

https://incompliancemag.com/article/all-ferrite-beads-are-not-created-equal-understanding-the-importance-of-ferrite-bead-material-behavior/

Quote
Another way to look at this is in terms of what the part is actually doing while in its inductive and resistive stages. Like other applications where there is an impedance mismatch with inductors, part of the introduced signal is reflected back to the source. This can provide some protection for sensitive devices on the other side of the ferrite bead, but also introduces an "L" into the circuitry and this can cause resonances and oscillations (ringing). So when the bead is still inductive in nature, part of the noise energy will be reflected and some percentage will pass through, depending on the inductance and impedance values.

When the ferrite bead is in its resistive stage, the component behaves, as stated, like a resistor and therefore impedes the noise energy and absorbs this energy from the circuit and does so in the form of heat. Though constructed in an identical manner as some inductors, using the same processes, manufacturing lines and techniques, machinery and some of the same component materials, the ferrite bead uses a lossy ferrite material while an inductor utilizes a lower loss ferrite material. This is shown in curves of Figure 2.


1008_F2_fig2

Figure 2: Reflection vs. Absorption

This figure shows [μ''] which is used to reflect the behavior of the lossy ferrite bead material.
Steve Greenfield AE7HD
Drawing Schematics: tinyurl.com/23mo9pf - tinyurl.com/o97ysyx - https://tinyurl.com/Technote8
Multitasking: forum.arduino.cc/index.php?topic=223286.0
gammon.com.au/blink - gammon.com.au/serial - gammon.com.au/interrupts

ted

@polymorph

Thanks for this info, I never consider that.
Where I can find similar info to compare totoid with rods ?

allanhurst

Just curious......

where do arduinos come into all this?

Allan

falexandru

@Allanhurst

The project consists in:

a) Photovoltaic charger - see separate thread - completed
b) Wind turbine charger -  this thread - ongoing
c) Lighting system - simplified version so far - no thread foreseen
d) Control system - under preparation by providing control points in each of the components above (a, b,c). - no thread by now.

The d) - control system - is where the Arduinos come in.

Step by step :-))

+++

[OT maybe: I love to understand what I am doing, even in the simpliest cases. See the Joule thief circuit- everywhere is given as a "simple thing to make". Yes, but is not as simple to understand. I hate "monkey see monkey do" :-)))]



polymorph

Where I can find similar info to compare totoid with rods ?
From the manufacturer of them. No one but them can say exactly what is in a given ferrite toroid or rod but the manufacturer.

You can get some idea if you have an LCR meter. Wind 10 turns on it, measure the inductance. Knowing that for a toroid, the inductance is proportional to the square of the number of turns, you now know how to calculate the number of turns to get a given inductance.

IMO, a joule thief is not a good choice for this. Who knows how efficient it will be? Likely not very efficient. There are chips custom made for this sort of thing.
Steve Greenfield AE7HD
Drawing Schematics: tinyurl.com/23mo9pf - tinyurl.com/o97ysyx - https://tinyurl.com/Technote8
Multitasking: forum.arduino.cc/index.php?topic=223286.0
gammon.com.au/blink - gammon.com.au/serial - gammon.com.au/interrupts

falexandru

Simplicity is more important than efficiency, because the project is a demo for kids.

And is a nice way to learn. :-).

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