Dr Ronald Stiffler SEC technology

[AlienGrey]

Hi AG,
Just a curious question: how do you know that one of the harmonics of the narrow 60 kHz pulses do not just hit coil resonance?   
IF you could change the 60 kHz frequency by a potmeter at the NE555 and sweep up and down say 20 - 30 kHz and see the change in brightness, that would be a good test for that.   OR you may have done so?   

I think though that your aim was mainly to show an increase in brightness when a kind of ground is introduced to the bottom of the load which is fed from the top of the coil.

Thanks,   Gyula

The mini Tesla coil resonance 1.2 mhz it's 8hz, so is 60khz but some peeks along the line will be higher than others. The NE555 can only go so
far, with the spike width i'm using, the charge discharge is split with RC and controlled with diode steering two presets.

The idea might be better suited if the wingdings (wire length) was tuned to say 1/8 wave i/4 wave ect and use a higher narrow voltage spike lest wast.

Gyula is that it, the pulse width harvesting all the harmonic energy ?

[gyulasun]

Hi AG,
If your coil has a self resonance at 1.2 MHz, then a 60 kHz narrow pulse can excite it with the 20th harmonic.  All I meant to vary the frequency of the NE555 timer, if it cannot go higher than 60 kHz, then it can go below 60 kHz, just to verify for yourself that the coil works or does not work at its resonant frequency, driven by a subharmonic pulse... 

And what has 8 Hz got to do with this all, I wonder?

The mini Tesla coil resonance 1.2 mhz it's 8hz, so is 60khz but some peeks along the line will be higher than others. The NE555 can only go so
far, with the spike width i'm using.

The idea might be better suited if the wingdings (wire length) was tuned to say 1/8 wave i/4 wave ect and use a higher narrow voltage spike lest wast.

[gyulasun]

...
Gyula is that it, the pulse width harvesting all the harmonic energy ?

Yes I think so. A rectangular and narrow pulse is full of harmonics.  and the 20th or the 19th or the 21th (or whichever nearby) harmonic is amplified by the relatively high Q of the coil, even if it is top loaded by the LED.

[gyulasun]

Hi Nick,

Your oscillator is surely not working at 60 Hz, the coil and the wires just pick up the stray field of the mains, from the house (or street) mains wiring.  When you touch wires, components pins and see 60 Hz amplitude increase on the scope your body surface which is merged in the 60 Hz field is added to the pick-up wiring of your setup,
The culprit in crystal oscillators is the transistor, this is the first to choose correctly, I wrote about this. The next component is the crystal but you have two of them now so its is unlikely that both are faulty. 

I suggest the following: remove the crystal from the oscillator.  Switch on the supply voltage to the circuit
Then drive the base of the transistor from your function generator set to its highest 2 MHz output frequency, but the amplitude should be only say 20 mV peak to peak, measured across the base and the negative rail.
You can adjust the 20 mVpp first by checking it on your oscilloscope. The generator output can drive the base via a 100 nF capacitor, the generator ground connection can be directly connected to the negative rail i.e. to the emitter, ok?

Now check the collector waveform, how it resembles to or differs from the 20 mVpp input sine wave?  Connect the scope ground clip also to the negative rail and the input clip directly to the transistor collector, use DC coupling for that scope channel.
If your choke coil in the collector indeed has 1000 uH or around that inductance, then it still can surely represent a decent AC impedance to the collector so you must see a much higher than 20 mVpp waveform.  This would mean the transistor is able to amplify at least at 2 MHz. IF you measure say 4.4 Vpp on the collector, then your amplifier can amplify 4400 mVpp / 20 mVpp = 220 times.
Sorry to give you such "home work" but this method could check your setup at least at 2 MHz how it behaves as an amplifier, a fundamental building block needed for an oscillator.

Of course, just check the total DC current your transistor draws from your battery or (power supply) you use for feeding it (I still mean when crystal is removed). 

If you do not get something from what I wrote above,  please ask. 

Gyula

[NickZ]

  Ok, thanks again Gyula.
   I did some changes to the circuit, as it won't fire up. First off, I changed the 1815 transistor back to the 2sc5200, as that one was working previously. I also removed the big AC choke and filter cap, and just left the 0.1uf.
  I installed a plug for the crystal, to be able to change them. And I'm now running the input from a 5watt solar panel, with about 20v.
  The 60Hz is due to my bare feet on tiled floor. Which I'm aware of. So, I isolated the circuit from any stray AC capacitive influences, also. And lift my feet off of the floor when testing, holding my breath to see if the circuit works. But, it doesn't. And I started turning blue.  However, I think that I see where the problem is, now. So, I'll take care of that, and report back.
   Thanks again,                          NickZ