Joule Thief

[electricme]

@all
I COULDNT GO TO BED, I had to come back and fiddle n solder again. 
its 12.43 am what a glutton 4 punishment ha ha.

I found out something, the freq energy being put out by each seperate coil is DC pulses, a great streeeeem of them.
OK we should be thinking of some termonology to identify these output coils, I will call each coil either a or b or c or d etc etc.

Experiment
A LED is a DIODE, it can only light up one way, so I tried connecting a LED across the output of coil "a", it didnt light, I reversed the connections and viola, success, it lit up VERRY VERRY bright, almost BLINDED me.
(This is powered by a single 1.5v AA cell, shhhhh don't tell anyone lol)
I'm tooooo tired to do any voltage tests, thats for when I wake up, gonna sleep in tomorrow I think.

I did the same with coil "b" it also did not light, reversing the connection produced a lit LED, it also was VERY VERY bright.

I did notice something, the 1st LED at the jule thief itself dimmed when a load (2 leds) were attatched to their respective coils "a" and "b".

please see photos
photo0201 = shows the JT working, 1 led is lit brightly, so bright it is flaring, need sunglasses, hurts eyes.

photo0204 = shows JT led "on" not so bright, Coil "a" is on, LED is very bright indeed

photo0200 = shows JT led "on" not so bright, Coil "a" is on and coil "b" is on, Both LEDS are very very bright.

In the photo you can see 2 switches, I can turn on either "a" or "b" coil on together or seperate.

@ist, yep torids are good fun, I had a fun fun day. I will have to keep my eyes open for BIG torids at the dumps or the local junk man.
ist, my LEDS are so much brighter than normal, I tink I burnt one out, opppps e daisy, never mind, I got heeps more.
I need a sleep, I 2 silly 4 words.

jim 

[Goat]

@ All

Do not stare at high brightness LEDs, because doing so may cause permanent damage to your eyes.

From http://cappels.org/dproj/LED%20Warning/Danger_of_Eye_Danger.html

Other than that, love this thread, keep picking at it 

Regards,
Paul

Hi All

I mentioned this back on page 59 and no one commented but after the last post by electricme (which is quite impressive BTW) I felt this should be repeated here and possibly added to the beginning of the thread to warn people of the possible dangers of starring at bright LED's.

If anyone can post this warning at the beginning of this thread to warn people I would be relieved.

Regards,
Paul

[Trino Cularoid]

that's how it works, as simple as that. no puzzle at all.

However, keep in mind, that it can work somewhat differently if configured (intentionally or not) accordingly (taking into account [transistor] non-linearities, parasitic capacitances/inductivities, etc.). [See e.g. some of my previous postings/references in this thread.]

[Artic_Knight]

hi, i seen on the first page you were using a 1f super cap same as me! i am having some difficulty with the curcuit lasting more than a minute and i think its due to my wireing.  i have a npn transistor thats a positive base right? seems to be activated by a positive charge. now if im using that do i still use the opposite bias transformer coils? ie a1 and b1 are the same end of the wire when starting the turns and b1 and b2 is the "folded end" that was cut after winding. and in an opposite bias we use a1 and b2 for positives forcing the electricity in opposite directions should both coils have power.

on a side note of how it works when the current flows through the white led its supposed to activate the transistor right? then allowing the current to bypass the led for a breif second and then it has to build up again to pass led again? which means the forward flow of electricity in the primary (led) coil needs to activate the base of the transistor magnetically in the transformer coils?

[Artic_Knight]

i have used as low as 7 turns and lit 45 leds

the resisitor is nessary it is your freq... it chokes the first coil down and saturates the core 

so if the resistor is the Freq, then a larger resistor will slow the pulses? and this is the same resistor on the coil feeding the base transistor the trigger coil right?