Dr Ronald Stiffler SEC technology

[itsu]

Hi Itsu,

Very good, thanks for your efforts.  Here are some refinements if I may, to get a 'nicer' waveform and perhaps less heat for the transistor.

May I suggest to reduce the number of turns from 26 to only 18 and make a tap at 4 turns?

From this link http://toroids.info/T200-2.php  the A_L value is about 12 for this core and 26 turns gives 8.1 uH while we need only around 4 uH, this is approached by 18 turns to get 3.8 uH. I mention this because the scope probe may have 15 pF and your 30 pF trimmer cap is turned fully out, very likely an even smaller than 15 pF overall tuning cap would be needed to tune the tank to resonance with the present 26 turns.  Notice that you may have to retune the trimmer cap when connecting an air coil  via a single wire.

And raising the number of turns for the tap from 2 to 4 would increase collector impedance, hence less AC collector current could flow, reducing dissipation. This may involve less peak to peak RF voltage across the tank due to the smaller transformation ratio, maybe an acceptable compromise.
But anyway, now you have roughly 50-55 Vpp voltage across the relatively high LC tank impedance and this would drive an air core coil (tuned also to 13.56 MHz) via a single wire nicely I suppose.  Then the resonant air core coil may have an even higher oscillating amplitude to feed a 230V LED via AV plug (maybe you do not have a 120 V LED). Try to connect (at least) two-two 1N4148 diodes in series to increase their reverse voltage rating.

A question: what is actual DC voltage feeding the oscillator? (due to the voltage drop across the 5 k trimmer pot)
Edit: if you have an L meter, please check the 26 turns inductance., to learn about reality.

Thanks, Gyula

Gyula

My agilent U1733C LCR meter shows 8.28uH @ 100KHz for the 26 turn coil, so your link is smack on.
The trimmer cap measures 4-23pF and was set at minimum (4pF), my probe is a 8pF type.

As i wanted to show off i turned the 5K trimmer pot all the way down (0 Ohm) so the voltage used
was from the battery meaning 12.4V.

I will remove some turns and go to 18 turns with a tap at 4.
I do only have some 230V leds here.

Thanks,   itsu

[gyulasun]

Hi Slider,

It is worth visiting your shed once in a while, you have a plethora of exotic components for sure. 
The other crystals with 37600 labels on them are surely overtone ones and their base frequency is either 1/3  i.e. 12533.3 kHz or maybe 1/5  i.e. 7520 khz you can plug them into the oscillator circuit and check with the oscilloscope.
Now that you received SEC 18-1, new fun begins.   


Gyula

[erfandl]

good idea with boost converter. I used LTC1871 boost converter module with a 3.7 volt polymer battery.

[Slider2732]

Gyula - LOL !
I repeated your comment about the shed to my wife and she said "Wouldn't surprise me if you found the Ark of the Covenant in there one day".
Most of it was useful stuff found during Minnesota Clean Up Weeks before we moved here to OK, literally picked up off the streets.
Then, a guy dropped off 4 plastic large tubs of stripped electronics, he had been after any precious metals and copper. That trash was my gold and still is, several years later.

erfandl - It's so good to see another one of those running 

There are displays for similar low cost that have the voltage and current on them and may be an upgrade route.
This one is similar, can't find the exact one that I have:
https://www.ebay.com/itm/DC0-100V-100A-50A-10A-LED-DC-Dual-Display-Digital-Voltage-Current-Meter-Hea-T3E4/183170385950
For a built-in setup where the screen is actually on the booster, such a screen would be on the output and would allow the measuring of current...something which I know Lidmotor has had troubles with and might hopefully be a fix.

[Lidmotor]

erfandl and All-----I was able to get this 'Crystal Circuit Exciter' to stay running at 20 volts (the voltage Dr. Stiffler used on his signal generator experiments).  The led array I am using came on super bright.  At that brightness be careful about looking directly at it.  I saw spots after doing this experiment.  Here is the short video of this thing at 20v.  The camera dimmed the light appearance down.  It is much brighter than it appears here.


https://www.youtube.com/watch?v=vW4RqHaZa-Q

--Lidmotor

PS---Slider I just ordered one of those voltage AND amperage meters off EBay.  We need to know the wattage or this experiment is somewhat meaningless.  The field 'excitation' messes with the electronic meters though and I really don't trust them.  Measuring the voltage drop across a resistor is a better way.  I will say this ---- That little MPSA06 didn't blow up producing a huge amount of light.  Interesting.