Dr Ronald Stiffler SEC technology

[gyulasun]

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   I've got it lighting on 12v, and just being careful not to overheat the transistor. I tried adding a 150K resistor in line with the 100k resistor that's on the base, but it would not start. And so I removed it, until I can find a more suitable one.
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Nick,
Please connect a 22 pF or a 33 pF or a 47 pF capacitor (whichever you have) across the base and the emitter of the transistor when you use the 150 kOhm (or higher) in series with the 100 kOhm base resistor.  Also, you can increase the value of the 22 pF capacitor, presently across the collector and the emitter, by connecting in parallel with it a 10 pF or another 22 pF capacitor.

Can you check the DC input current to the oscillator when supplied by 12V?  You can pull out the crystal and then plug it in to see current when the oscillator works. 

[NickZ]

thanks NickZ. how to provide output to input for looping ? do you connect 2 diodes to battery ?

   Not sure yet. But, maybe your idea might work.
  The oscillator is already providing more than a SG does at over 30v, at 135MHz.But, I see nothing special, as yet. I don't have the right bulb though.
   NickZ

[itsu]

Gyula,

Hi Itsu,

The 18V DC is created by the AV plug diodes across the LED diodes (7 LEDs in series and this is in parallel with another 7 LEDs also in series).
You know the voltage - current characteristics of LEDs are like that of Zener diodes hence the 17.8 to 18 V DC level automatically developes across the array (LED string).   
Seemingly the basic 3 V forward voltage for a single white LED is not valid here because 18V / 7 = 2.57 V only, instead of the 2.9V to 3.3V range but I think this lower value comes from the parallel connection of the two series strings. (like for Zeners or for normal diodes the parallel connection does reduce the original Zener breakdown or forward voltages)

If you connect two such LED boards in series to add their '18V levels' and feed them with the AV plug, then the input RF energy may be able to light them both, albeit they maybe would not have similar brightness than in the single board case.
And you would then see a 33-35V or so DC on the scope Math. 

Correct, when i put 2 of those leds strip in series, the signals look like as in the 1st screenshot below.
The leds are almost off, but they are lit and the math function shows the DC voltage to be 33V.

By the way, I assume if you connect an electrolytic cap across the DC wires of the LED board with the correct polarity, then it would serve as a puffer capacitor for the AV plug diodes and maybe you could check the DC level not only with the scope but with a normal DC voltmeter.
A 47 to 100 uF, 25 or 36 V rated electrolytic would be ok for such test. (Notice: if you remove the LED board from the puffer cap, then a 160V DC rated capacitor should be used to handle the unloaded DC level from the AV plug.)

Correct again, the puffer cap cleans up the signals and enables a DMM to read the 33V.

Regarding the need for a capacitive coupling when the xtal oscillator drives the 3 coils instead of the FG, I think also the input of 3 coils may represent a low impedance and loads down too much the toroidal tank.
Perhaps you can see this on the scope what happens to the near 100 Vpp across the toroidal tank when you attempt to drive the 3 coils.

Could you use a low pF value trimmer capacitor instead of the PC board? I mean a few pF, max say 10 pF.
To make the tuning of such capacitor relatively hand_effect_detuning free, you could make a 'trimmer cap' by twisting two enameled wires together, say you make a 10 cm long twist and leave the 2 wires open at one end.
Then connect the two other wire ends as a coupling capacitor between the tank and the 3 coil setup.
To tune such capacitor, just cut down the open end of the twist gradually say by 1 cm or half a cm at a time and see the brightness.

The 2th screenshot shows the oscillator output without the 3 coils attached in white (143Vpp)
The yellow trace is the signal when connected to the 3 coil setup with a trimmer cap (set to 5pF).
The blue and purple are again the signals across the SINGLE led strip with the red trace the math showing the DC voltage again.

Without the 5pF trimmer cap the signal collapses from the 143Vpp to zero (shuts down the oscillator).

Finally the diagram as i now have the 3 coil system setup, which is how i think Dr. Stiffler meant it

Itsu

[itsu]

Hi Itsu,

2.2 mA forward current at 17.8 V: that is rather low. It means the individual SMD LEDs on those boards are already able to give brightness you show in the video from 2.4 - 2.5 V individual forward voltage levels.

Specifications on the 5050 LED chips:
https://www.superbrightleds.com/moreinfo/surface-mount-smd/warm-white-5050-smd-led-120-degree-viewing-angle-6000-mcd/317/1249/

For any single SMD LED chip (that your boards include) the forward voltage is written to be 3.2 V at 3x20 mA current this is because any single chip includes 3 LED diodes integrated and connected in parallel within any chip.

The parallel connection of two series strings on a board having 7-7 such chips reduces the specified 7x3.2V= 22.4V at 60 mA: you made a test at 60 mA and the voltage was 20 V from the PS or your another test done at 67 mA needed 20.3V (7x2.9V), this is possible and comparable. The resulting reducement in forward voltage for parallel connected LEDs is similar to that of Zener or for just normal diodes.
I do not think your earlier RF current measurements were false (around 50 mA taken from the 12.5V battery), you confirmed this with an analog ampermeter too. Back then the LED board was driven by its back plate via a single wire from the L3 coil, now you drove the LED board from an AV plug which was driven from the 3rd coil of a 3 coil setup. Also, the capacitive coupling you created between the wire from the input to the 3 coils and the PCB plate has an unknown pF value and its capacitive reactance reduces the RF voltage coming from the tank.

OR you meant input current measurement problems in the present case when you drive the 3 coils by the oscillator?

Thanks,  Gyula

Gyula,

i checked again with my DC PS, at 20V they draw 60mA, but at 18V it drops to 2.6mA with moderate light.

Yes, i meant the input current measurement  is not possible when i drive the 3 coils by the oscillator.
Probably the RF emitting from the 3 coils is to strong, as even without any cables connected to my analoge
meter it reads 5mA or so (nearby off course).

Itsu

[gyulasun]

Hi Itsu,

Thanks for the comments and measurements,  I appreciate your work very much.
I agree with the schema you show on the 3 coil setup as the Doc introduced it in his video.  Does the trimmer capacitor set to 5 pF give a resonance-like coupling? i.e. can it be adjusted to give a peak brightness and that happens to be around 5 pF? or it has a 'flat' response? Just curious. (I know it is difficult to adjust due to the hand capacitance, perhaps the use of a piece of wood or plastic rod formed to have screwdriver end would reduce hand effects when turning the trimmer with them.)

In the 3 coil setup there are the AV plug diodes inserted between the input coil and the middle coil. This is an unusual connection because the DC resistance of the second coil short circuits the DC component of the rectified RF energy and "only" the RF signals remain to feed the top and bottom ends of the middle coil.  Have you pondered on this DC short?
When you have time next week, could you place the two probes to the ends of the middle coil and use the scope in differential mode to see how the waveforms look like? 

I assume you changed the distance between the input and the middle coil?  Is the distance critical between them in terms of the brightness?

And the most interesting thing is his 1 Ohm voltage drop measurement right at the output of his generator. Have you checked when you remove the 3rd coil with the LED board (as he did) then how the amplitude of the oscillator tank changes? That would be the goal to achieve what he stated: the energy taken out from the generator does not change.

Gyula