Joule Thief

[jeanna]

Jeanna

I tried a few setups  using  caps  between the inductors ....... so far nothing  has  worked ....     

I remember  something about  Tesla  adding caps to the circuit .......he said " always do this "
Do   you  remember that ?    Do   you remember how he was using them ?

I thought I would pick up that scribd book again. I didn't get to it today.
What I remember is he said it had to be tuned. He did not use the word "fiddly" but he said something of the sort.

It took most of the day but  I finally got most  of my stuff working again.
It turns out that I did not  burn  out my 3055 after all ....... 

Oh that is terrific!
Now, if only the same could happen for jesus....


Well Gary, let me know what you find out. Maybe I will start to report my difficulties next door. If you want to talk about matching inductors and caps over there, we could do that. I think it is the main issue in keeping the ac/pulsed dc that way

Hmm,
I remember one of tesla's tricks was to add a cap to one secondary line but not the other. In my mind, this delays one of the pulses.
That is the reason I split the line. One secondary line was unchanged, then the other was split. This other one had identical pulses which were opposite to the pulses of the other (un-split) wire.
So, now if you can take a powerful pulse and delay it in part of the circuit, you can have a big voltage difference.

Doing it, however...
I did it one way but now I want to get another way.

It is in part what the hairpin lighting experiment was about. I think I need to read that lecture first thing tomorrow.

jeanna

[Pirate88179]

Jeanna:

First, very nice work with all of your scope shots you posted.  A lot of very well explained data there.  (I am so far behind with all of the topics it is not even funny)

Next, the Tesla idea that you just mentioned is very fascinating.  It sounds so much like him, so simple (once he shows us of course) and yet so complicated in the results.  That might be a cheap and dirty way of establishing resonance in any circuit of that type, regardless of the other variables as long as everything was identical prior to adding the cap to the one side only.  What a great concept.  I think I can see how this might work.

Thanks for posting this here.

Bill

[xee2]

@ nievesoliveras

There is a very small circuit tha uses 5 volts to light a cfl.
I was checking it today and it only uses two transistors, three cpacitors, one resistor and a small transformer.

Can you post a link to the circuit diagram or post it here? I think that to be fair in comparing performance the total input power (amps times volts) should be compared with how bright the bulb gets. Maybe you have found a better performing circuit than the JT.

[xee2]

@ Yucca

Hi xee2,

Rest assured it runs at 1.5V supply, my scope confirms this, as does the fact that it will run on a single AAA alkaline cell (after jump starting). And it oscillates and excites the neon.

The secret is that it will not start at 1.5V, It fires at 4V, but then you can wind down to 1.5V before oscillation mode collapses at anything lower.

This is one very handy aspect of a variable supply, many more exoticly wound JTs are built which appear dead, but they just need a kickstart and then you can wind them down into the lower voltage range.

I have studied it more carefully using my DSO and a resistive 1ohm shunt. here are some figures that are reasonably accurate:

supply voltage: 1.5V
true RMS input power: 2.4mW
power wasted in bias resistors: >=2.0mW
peak base voltage: 5.68V
oscillation frequency: 37.1kHz
HV out (with neon lit): oscillates 60V to 84V

Thanks for the info. I tried to duplicate your bias circuit using an AA battery and it would not oscillate. But I can see that once it is started at a higher voltage the voltage can be droped. I am very impressed that you can light a neon with less than 2 ma at 1.5 volts. The best I have done required 4 ma. Please keep reporting your results.

[Pirate88179]

@ Jesus:

Just to point out that, as shown in Jeanna's posting of the circuit board, it is a CCFL not a CFL.  Wilbyinebriated made a nice light from a small beer keg and some CCFL bulbs.  It is way back on here but you might pm him and see what circuit he used for it.

Bill