Joule Thief

[xee2]

@ @ jeanna

Really then, one becomes the ground or reference point for the other.

Yes. When measuring the voltage between the two ends of a battery. If the ground clip is connected to the negative end of a battery, then you will measure a positive voltage at the probe. If the ground clip is connected to the positive end of the battery, then you will measure a negative voltage at the probe tip. The scope, or voltmeter, displays the probe voltage relative to the ground clip voltage.

[jeanna]

@xee2

Thank you,

to one of the secondary lead of the coils you want to measure and the other probe to the other lead.

so i guess what is buggling you is if your measurements are meaningfull or not, is that it ?

Thank you theNOP,
Sorry I missed your reply earlier.

Yes, I am not sure my measurements are meaningful.

On the one hand ,

Yesterday while testing the MK1,

I filled a cap with 110 volts after running those volts around a bridge rectifier.
The dmm saw 39 volts from the same set up.

When I hooked the 2 wires of the secondary to the probe and clip of the scope,
The scope only saw 24 volts with the spikes going one way and 25 volts with the spikes going the other way.

On the other hand,

Using the same arrangements but testing the MK2 a few days ago
The dmm reported seeing 38.9 vdc
The cap hardly collected anything I cannot find my notes of it. I probably didn't write it down and kept fiddling to fix or figure what was wrong. I think it was something like 4.8 or 6vdc

This time the scope said the combined sides of the MK2 had a peak to peak voltage of 108 vAC. But this is when I tried to get the led string to turn on but it wouldn't.

So, I am getting too low or too high results and I am using the probes on each wire of the secondary so this is the curve.

thank you,


jeanna

[Pirate88179]

@ Wilby:

Now that is an excellent idea!  Do you think the bird would move ok with the slight added weight of an electrical contact?  This I have to try.  Great thinking.  Thank you.

@Gyula:

Thank you for that scope info and the links.  I will watch the vids and read all of the information.  I appreciate your posting it.

@ Jesus:

Thanks for your compliment on my latest video.  Thank you for posting the drawings of the MK toroids, I am sure this will help folks, including me.

Jeanna:

About the sheep....I don't know what to say.... ha ha.  What will they think of next?


@ TheNop:

I see what you are saying but I am not totally convinced this is the case.  At first glance it would appear to be.  But, think about this, we know the led is off and on so fast we can't see it but it is this off time that I believe contributes a lot to the longevity of our lighting from a small power source. (1.5 AA)  OK, so to pulse the battery say once every30-60 seconds for 1 second I believe would add to the efficiency of the circuit by being "off" as much as it is "on" at those intervals.  Now, I believe you are correct about the supercaps pulling the "juice" they need to tun the leds for the selected time interval, we can't get around that.  My line of thinking is that by hitting the supercaps for only 1 second will allow less juice to be pulled from the battery over time as there would be if connected 100% of the time.  In other words, what I am trying to say is maybe this would increase efficiency a bit over a given time period, it would not, of course, be OU or even U.  Possibly it would be a step closer to U.  I guess the question is this:  Do the supercaps continue to pull anything from the battery once they are fully charged up?  If they don't then my idea is full of crap as this would make the battery "think" it was off until the caps needed more power.  If there is a continued drain once the caps are full, then I think this idea may have some merit.  Once again, I freely admit....I don't know.  It should be pretty easy to test once I get the pulsing mechanism worked out possibly with Wilby's bird.  Thanks.  PS  You might be correct about the battery chemical reaction downtime effect.



Bill

[jeanna]

@Bill,
Don't you want to be filling the cap from the secondary?

Since we show over and over that the amps draw from the battery is no more and frequently less with the addition of the secondary, you would be filling the cap with no extra loss from the battery.

I don't propose to know how to set up the design to do this, [perhaps another jt type switching circuit with a really high value resistor]  but it seems the obvious thing to me when as long as the battery circuit is going, the secondary will fill the cap. Once the cap has filled the first time, it will take over and only go off when it is completely exhausted from getting secondary juice from its own push in place of the battery.

Thinking in terms of time, if the fill time of the cap is 1/8 the emptying time then you will have a loong time before the thing cycles itself off and needs to turn on the battery again. And that would be on for another 1/8 the time the cap could provide the energy for the secondary to refill the cap.

I think your battery would last 8 times as long as with a jtc. since it would be off for so much of the time.

jeanna

PS corse, it did seem that the cap was running things for 20 times as long as the battery. I forget if you timed it?

[TheNOP]

I guess the question is this:  Do the supercaps continue to pull anything from the battery once they are fully charged up? 

if no other things are connected the answare is no.
once a cap is charged currents will stop flowing.
this is true for DC.

in our case, a current will be draw from the cap and cap will be filled at same time by the battery.

one more thing that might encourage you is that the frequency is changing with the voltage.
a cap voltage is dropping faster then a battery.
that is about the same as setting the jt for lower frequency.
but we know that setting the jt resistance for lower frequency will cause problems with transistor triggering at a higher battery voltage.