Joule Thief

[jeanna]

i think the "make and break" was a rotary swithching device, kinda like relays.

the reason i think this, is that spark gaps need relatively high voltage to start sparking.
hv was not really what was used the most at that time.
in some researches perhap, but not mainstream.

In looking for the post from jesus that I missed, I found that I had missed this one as well.

I have a quote from master Tesla.
He does not directly say that the make and break is sparks. he does by inference, however.
He is advising the use of an alternator here, but for the last many pages in his lecture he has been describing spark gaps and how to fix the problems.... and most recently he was describing how easily people came to wrong conclusions about sparks and where they are coming from.

In order to make reliable observations of electric resonance
effects it is very desirable, if not necessary, to employ an alter-
nator giving currents which rise and fall harmonically, as in
working with make and break currents the observations are not
always trustworthy, since many phenomena, which depend- on
the rate of change, may be produced with widely different fre-
quencies.

Please excuse this outburst.

jeanna

@jesus,
I cannot find the post I missed. I am NOT ignoring you.

[jeanna]

@jeanna

Sorry I have not posted those results as of yet I have been working non stop Can you please PM what you wanted to know again. I should have a few hours off tomorrow night.

-Altrez

Hi Altrez,
I want to know how this big toroid core works for you. And the way I want to know is to ask you to use a regular joule thief circuit and measure the frequency and volts off each secondary/pickup you have wound.

but first I will  need the transistor, battery voltage, if you are using a cap, one led or none on the basic jt, the resistor value all on the joule thief.

I guess I will want to know how many turns are on the primary also.
You know like 4T,5T,94T that kind of basic information.

So after the jt is going, put the aligator clip on one side of one pickup wire and then the probe on the other. Adjust the scope for best voltage which is usually where the curve is too small to examine it, then zoom in with both voltage and frequency, and place the markers on the same spot of the wave (same spot plus 1) and read the frequency.

I would like to know what that is on the various number of turns. If they are all the same then only do this once.

I guess this is it.  You posted pictures and a lot in the beginning but I never saw these basic pieces of information. And besides the scope was so new and all...

thanks a lot,

jeanna

[xee2]

Hi everyone,
I am interrupting a test to report this.
It is about adding a cap across the base resistor and looking at the voltage drop way way down.

I am getting better and better at understanding what I am seeing on my scope so I understand this better and here is what my scope is showing for the difference without a cap and with a cap.

with all the usual and no led, just the bjt without led
_~~~~~~~~|_~~~~~~~||_~~~~~~~~|_~~
the scope reads this and reports 65volts. but the little wave at the bottom is around 6 or 7 volts. see below:

now with the cap and still no light

_|^{`~~</sup>|_|<sup>`~~}|_|^{`~~</sup>|_|<sup>`~~}|_

the scope reads this and reports 7.7 volts.
It seems the cap can see and smooth out the spikes and incorporate them in the wave. And the scope calls it voltage and shows it. I know the folks with schooling in EE and folks who own scopes know this, but I want to verify it and make this little php drawing for the rest of you. Now back to the kitchenlab!

jeanna

edit
MK1 that is a nice explanation. carry on with that please. I am beginning to understand a little.

Thanks for this info.

[xee2]

@ jeanna

The area in the spikes on the scope correspond to the power being delivered to the load. As you can see, with the cap the voltage is less but there is more area in the spikes thus more power is being delivered to the load with the base cap. At least that is how I would interpret what you posted.

[jeanna]

Thanks for this info.

you are welcome.

@ jeanna

The area in the spikes on the scope correspond to the power being delivered to the load. As you can see, with the cap the voltage is less but there is more area in the spikes thus more power is being delivered to the load with the base cap. At least that is how I would interpret what you posted.

I kind of agree in that the total area under the spike seems to be what can be used. It is the reason I keep going for the "quality" of wave.

On the other hand, Tesla says the higher rate of increase (in volts) is more important than just the increase, indicating that the fast veritcal spike is able to deliver more.

It is for this reason that I am unsure if I should use the cap.

It seems I should, because the folks with the best results all seem to be using them in their circuits.
And you have them in 2 places and light fluoros with ease. I think the cap you have for reading your results may be helping with lighting too.

My mind is going back and forth like my toroids today. Maybe it is time for dinner.

jeanna