Agentgates´s TPU setup with strange wavehill hump

[hartiberlin]

Hi Mark,
so you say you have 160 Milliamps as the input current.
That would be around 160 MilliWatts, if the 1.2 Volt Battery
is about loaded like this it would probably only produce around 1 Volts.

Or do you use 2  x 1.2 Volts batteries in series for the JT circuit ?

If you get a 6 Volts 250 milliamps bulbs to glow pretty brightly,
that would mean around 1.5 Watts of output power from
160 MilliWatts of input power ?

Can you please verify this again ?

P.S. Did you play with other JT circuits before ?
Did you have lower outputs with other normal coils ?

Many thanks.

Regards, Stefan.

[oscar]

Hi MK1,
I am in the process of building a joule thief with a Rodin style aircore coil similar to the one you show in your video
http://www.youtube.com/watch?v=eiLcbTBewhw

Thank you very much for making that video. Up till now i was hitting this kind of coils with a square wave generator.
Finally I understood, that a "self oscillating transistor" in joule thief style is the way to go.

In your video you wrote at 0:16  "On the first try I made it an X winding, the pickup coil gave me 0 Volts but still could light 24 leds in parallel"
Also, at 0:33 you wrote: "0 volts coil (X) At work!"

I got that same effect - lighting a LED on the collector coil with an immeasurable voltage - and obviously it is because this coil picks up some kind of AC.
Also a LED on such a collector coil lights both ways, weak in one way, yet much stronger when connected the right way round, no?
I scoped across a LED lit on such a collector coil. See the signal below.

[gyulasun]

Hi Oscar,

Many thanks for your answer here.
It is very good you attached the scope display picture. 
I think the LED is lit only in the peak pulse amplitudes (where your vertical time cursors cross the beheaded peak of the pulse) and if your zero line is in the center horizontal line, the beheaded peak amplitude is about 1.8V positive, this is what lights the LED (the LED limits the peak pulse at its forward voltage level).  (One vertical divison is 2 Volts, one horizontal divison is 5 usec.)
For the rest of the waveform the inductive ringing is seen as usual for an unloaded (but lossy) coil. 
The LED is ON for about 2 usec (the length of the horizontal beheaded pulse peak) from the full 15 usec pulse time.

Your observation on the reversed biased LED giving a weak light: you basically have an AC voltage between the collector and the negative line, however this is an assymetrical waveform, its positive peak is higher than its negative one, so whenever you connect the LED so that the negative peaks are the forward direction for it, it still lights but more dimly.

If you have an ordinary digital voltmeter, would you check what it shows in both its AC and DC ranges? Just for info, normally a 64-65 kHz pulse is a total failure for conventional 50-60Hz  DMMs.

Thanks,  Gyula

[Mk1]

@all

I started a new tread

http://www.overunity.com/index.php?topic=8878.msg231926

About the coil

Please come and join me .

Mark

@Oscar


Thank you , nice scope shot , was that from the transistor of the pickup coil ?

[oscar]

If you have an ordinary digital voltmeter, would you check what it shows in both its AC and DC ranges? Just for info, normally a 64-65 kHz pulse is a total failure for conventional 50-60Hz  DMMs.

Hi gyulasun

I tried that and it is exactly the problem: my cheap DMM has two settings/ranges for AC: 200V and 600V, and it does not give a reading for the signal that lights the LED(s), due to the problem you describe (the meter is not build to pick up AC in that frequency range).

I also get no reading when set to DC.

But please note: there are amps there. This is why it will light LEDs in parallel but not in series - if I am not mistaken. Also note the "directionality"
http://www.youtube.com/watch?v=0PdxlD4xOck