Joule Thief

[Pirate88179]

Jadaro:

The base line is the line with the little cross hatch marks running 90 degrees to the main line.  In that photo all of the waves are above the base and the bottom of the wave is sitting on the base.  I don't think this confirms your posit but, I don't really know what you meant.



Bill

[jadaro2600]

Jadaro:

The base line is the line with the little cross hatch marks running 90 degrees to the main line.  In that photo all of the waves are above the base and the bottom of the wave is sitting on the base.  I don't think this confirms your posit but, I don't really know what you meant.

Bill

Well, I mean, the Zero of the wave, where it crosses from negative to positive - or the neutral position - as would be the centerline of the wave.  My posit ( I forget the word earlier ) was / is / that the wave has what audio enthusiasts call a DC offset, where the centerline of the wave is offset from the waveform - in other words, it's off center.

[jeanna]

Thank you, as soon as I can afford a scope I'll probably get one.  I want to see what goes on across a coil NOT integrated into the oscillation mechanism, such as gadget's indicator light..just a reading on the bare wires.  Unrectified, I have a feeling it will look something like this, with a higher forward then back, just depending on the polarity of the probes.

No,
I can say it rarely looks like that.


I will make a little drawing.
Bill, I think yours is from the primary across the C-E isn't it?

It is a great pic of what gadget is capturing because this is where his cap is.

Unrectified it looks like trees along the street in winter.

______||__|___||_____||____|___|_|_|___|_____||____|__||__|
and they are often as varied for one coil as this is too.

---=========----
I have a pic for a saturday night.
Remember last year when I bought the string o leds and the results were horrid?
I had to have 300 v and still only half of the leds lit dimly.
Then I took it apart and found diodes in the wires embedded in a kind of foam plastic that had obviously been formed around the lights. ick.

I set them aside, and tonight was the night to do the deed.

I removed 34 leds from the rest of the wire strings but kept the single string, so there is 1 wire connecting them all.
I stripped each end and set it into my new high output tiny toroid.
this is the jt whose secondary is giving me 172v and I can tune it higher.

I showed it the other day with a neon. the MK1-jeanna hybrid...
so, I can say this is as bright as the string can be from the wall.
I have one in the wall for comparison, but for now here it is.
This is a lovely lighting for the hallway and around the house or garden.

jeanna

edit
jadaro,
yes it is a little off center. It is usually about 30% below the x axis.
My measurements are from peak to peak so that would not change, but yes, you are right about this.
j

[gadgetmall]

Closing the switch on this particular circuit cause the path to short ( bypass ) the oscillator; unless the capacitor and the nichrome wire are on a secondary, then the battery is directly charging the capacitor and the oscillator is providing additional voltage.  This isn't the circuit you're looking for... and after 10k posts I would have thought you all would realize this. ( I mean not to offend ...)  You can test the idea by removing R1.. the capacitor will charge without the oscillator and will charge to a voltage of the source minus the forward voltage drop of the diode D2.

Of course that wire is going to get hot..it's shorted either across the battery or the capacitor and it's running in parallel with said source ( going to the heater wire ).

About that secondary, which I know is optional,

@Jeanna, what does the waveform look like without rectification off of a secondary ( perhaps you have an old image)?

I couldnt resist . I jumped the charge cap to the run cap D2 isolated the circuit if you jump the hot wire to plus of bcap  and the LEds get brighter . and yes it get hot but the primary bcap charged very quick a 10th of a volt in a 2 second test .  we will have will only give a short burst to the aa battery after 14 hours . this it can handle . . Well this works . all we need is a 55timmer to flash a mosfet for 5 seconds . It works . I did this because i am on the third swap of these bcaps running the circuit for days now . I will redo the whole experiment all over again  this time one system will run from an aa battery and another will run from a charged bcap  and testing the threoy which is now proof that the charged bcap can recharge the primary in a very short time to recover what it lost . It works as it is now only thing needed is a timer to pop the primary battery  from the positive lead of the charge bcap . dont ask me why it works but it does .

Gadget

[Pirate88179]

Jeanna:

Very nice job removing the diodes!  That IS as bright as in the wall...excellent!

That scope shot was taken a while back and the probes were placed on the output of the JT where the led would normally be attached.  No secondary on that one, or any of mine...yet...until my big toroids get here and I replicate Lidmotor's Jeanna Light.

I went into the attic over here and found a nice little wooden box that was made to hold precision pin gauges.  The inside measurements are enough to house the big toroid.  I slapped a nice coat of walnut stain on it and, while it does not look as elegant as Lidmotor's, it should do nicely.

I was thinking, after looking at some catalogs tonight, of using a non-rechargeable industrial D cell.  It is rated at 14,000 mA hours!  Still 1.5 volts of course but, that should really run the cfl for quite some time.  I am not going to make the first one rechargeable like Lid did...going to try to keep it simple just to make one that works. (Someone suggested this, ha ha)

Again, great job on lighting those leds.

Bill