Joule Thief

[jeanna]

@Jeanna,

I think you might have to begin to include a "protection" resistor in your chain of LED's.
...

Thanks Jim,
There was not much indication that this would happen.

Take a look at the chart I was finally able to post, (If you are able to get it, that is.)

Look across just one line and you will see that the amps are well within safe range. The volts are lower and also the frequency is lower than many have been lately.

It was only when I actually put a led across the secondary that the mA went as high as it did!!!!

This is so odd. But that is why I made the orange burn color for this chart. (  )

Thanks for your kind help.


jeanna

[jeanna]

@All,
We already knew something like this, but I just quantified it a little bit. And maybe found a way to check first to be sure the amps draw wont be too high, or indeed what the amps draw actually IS from a secondary wire. Have a look.

jeanna

[TheNOP]

AC has special properties which we in this modern world (except for theNOP of course) don't know much about.

some peoples are even more knowledgeable about this i am.

those properties have been teached to me.
any EE, even simple electriciens, know them.
maybe not all can see how else, then in "conventional" ways, they can be used, but the infos about them are all over, in education book and internet.

please do some search, cross reference your finding, make your own experiences when in doubt.

when you don't see something, on the market for example, it does not mean it does not exist, have been forgot or was never studied.
more often then other, it is because of monetary reasons and/or ease of manufacturing that gouvern what will be available or not.

did you know that Tesla's hv coils have their modern equivalents ?
they are primarly used for testing dielectric materials.

in bref.
what i am trying to tell you is that your perception of what is know and what is not know, is based on your own knowledge.
not on the actual modern science knowledge.

[allcanadian]

@theNOP
Quote:
"you are assuming that 1.5 volts few mA can't do that.
i am not.
neither am i saying that what you have experienced can't be reproduce.
i can do the same thing, not with an electric toothbrush, but i can do it.
the lenght of the rod is not as important as the off center weight."

Actually I knew the results before the experiment, I was only proving them for myself. As for the off center weight (the motor), the same results were produced without the motor by striking the rod. The rod length itself (a mass) determines the rate of oscillation which is the cause of the effects, in much the same way as the potential difference induced at the ends of a length of wire is determined by it's wave period as well as the magnitude of the inducing force. In any case I posted this experiment so that others could understand that resonance can happen on many levels and is a major factor in the efficiency of any system.
Regards
AC

[Pirate88179]

@ Allcandain:

Yes, I agree with your example.  The length of the rod, its mass (which can also be a function of diameter) determines its frequency exactly like a guitar string.  Bridges have been destroyed with resonance. (Tacoma Narrows Bridge)  Also, aircraft control surfaces as well. (it is called flutter in aviation)  Very powerful additive/cumulative effects at work.

Bill