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Author Topic: Dr Ronald Stiffler SEC technology  (Read 278839 times)

NickZ

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Re: Dr Ronald Stiffler SEC technology
« Reply #570 on: July 15, 2018, 06:54:38 PM »
   erfandl:   My 13.5MHz crystal oscillator is pictured below. It runs best using the 7.2MHz crystal, or a 12.000MHz crystal.
   The diagram (below) was taken from one of Lidmotor's videos.
   I've provided for two outputs, one for the leds, and another for future power looping, back to the input.


mikrovolt

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Re: Dr Ronald Stiffler SEC technology
« Reply #571 on: July 15, 2018, 07:56:43 PM »
The projects getting better
https://www.slideserve.com/selah/bifilar-wound-toroids-session-2
https://www.bamlog.com/diyxfmr.htm
https://www.abcelectronique.com/annuaire/montages/cache/3560/melangeur-transmetteur.html

Hobbyist approach Doug DeMaw has good explanation hands on approach.
Starting on page 45 crystal circuits, impedance, vfo buffer, using small ferrite beads, ect

http://www.n5dux.com/ham/files/pdf/W1FB%20-%20QRP%20Notebook.pdf

erfandl

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Re: Dr Ronald Stiffler SEC technology
« Reply #572 on: July 15, 2018, 08:32:59 PM »
   erfandl:   My 13.5MHz crystal oscillator is pictured below. It runs best using the 7.2MHz crystal, or a 12.000MHz crystal.
   The diagram (below) was taken from one of Lidmotor's videos.
   I've provided for two outputs, one for the leds, and another for future power looping, back to the input.
thanks NickZ. how to provide output to input for looping ? do you connect 2 diodes to battery ?

gyulasun

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Re: Dr Ronald Stiffler SEC technology
« Reply #573 on: July 15, 2018, 08:45:12 PM »
Gyula,

thanks for the comments, i will digest them later this weekend.
The question you have i can answer, as the current pulled by the PS at 17.8V was 2.2mA.
Measuring the current from the battery feeding the oscillator was fouled up by RF? as i could not get
a correct reading.
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

gyulasun

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Re: Dr Ronald Stiffler SEC technology
« Reply #574 on: July 15, 2018, 08:56:29 PM »
Hi Slider,

First thing firsts: just test the oscilloscope and the probes with the built-in 1 kHz square wave output I assume you have in the front face (I do not know this scope type in detail).
Then if the scope is okay, then carry on exploring the waveforms from earlier known circuits. Then you can conclude something.

gyulasun

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Re: Dr Ronald Stiffler SEC technology
« Reply #575 on: July 15, 2018, 09:11:38 PM »
...
   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.
...
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

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Re: Dr Ronald Stiffler SEC technology
« Reply #576 on: July 15, 2018, 09:30:02 PM »
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

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Re: Dr Ronald Stiffler SEC technology
« Reply #577 on: July 15, 2018, 09:34:28 PM »

Gyula,

Quote
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.


Quote
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.

Quote
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

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Re: Dr Ronald Stiffler SEC technology
« Reply #578 on: July 15, 2018, 09:41:02 PM »
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

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Re: Dr Ronald Stiffler SEC technology
« Reply #579 on: July 15, 2018, 10:52:06 PM »
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

gyulasun

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Re: Dr Ronald Stiffler SEC technology
« Reply #580 on: July 15, 2018, 10:58:15 PM »
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
Okay, thanks.  The voltage-current characteristic of the paralleled LED strings within a LED board is very steap to cause the big change in current for the 2 V change in voltage.  But this is normal for LEDs.
I agree, the 3 coil setup surely increases the near field because all the 3 coils are air core coils and nothing confines their EM field like a ferromagnetic core normally does when used. 

gyulasun

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Re: Dr Ronald Stiffler SEC technology
« Reply #581 on: July 15, 2018, 11:11:44 PM »
Hmmm. increased the brightness by paralleling three 13.56 MHz crystal
Hi Erfandl,
I missed to comment your interesting test.  Would you check the DC input current to your oscillator how it changes when the 3 crystals work?

I think the number of oscillator harmonic frequencies are greatly increased with the use of 3 crystals versus a single crystal and this comes at a price of an increased input power too.   The harmonics can only be seen by using a spectrum analyzer (or a selective voltmeter). 
If you find the input current does not increase with the use of 3 crystals, that would be good news...  8)   but I think it increases.
Gyula

itsu

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Re: Dr Ronald Stiffler SEC technology
« Reply #582 on: July 16, 2018, 10:21:09 AM »
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

Gyula,

the trimmer cap does give a resonance-like coupling,  i use a plactic rod trimmer screwdriver to adjust.


I will take the differential probe measurement on the first AV-plug tonight.
I think we don't need the DC at that middle coil, just the RF AC to excite it.

Changing the distance between the 2 vertical coils has little or no influence on the brightness of the
leds, i demonstrated that in the first video of this setup in post #555.
So it seems that all the RF goes via the AV-plug / links.

Also the 1 Ohm csr measurement with removing the last coil/led strip combo was done in that video around
the 4 minute mark using my FG.

I see little or no change in current then,  but can repeat that for the oscillator circuit.


By the way, now with the trimmer cap set to 5pF and having the leds on using the oscillator i can again
measure the input current using my analoge voltmeter, its still 52mA with the leds at a 17.9V DC level.
(compared to the 2.6mA at 18V for the PS setup).
So the RF is loaded down enough to have no direct influence on the meter.


Thanks,   Itsu

erfandl

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Re: Dr Ronald Stiffler SEC technology
« Reply #583 on: July 16, 2018, 11:05:16 AM »
Hi Erfandl,
I missed to comment your interesting test.  Would you check the DC input current to your oscillator how it changes when the 3 crystals work?

I think the number of oscillator harmonic frequencies are greatly increased with the use of 3 crystals versus a single crystal and this comes at a price of an increased input power too.   The harmonics can only be seen by using a spectrum analyzer (or a selective voltmeter). 
If you find the input current does not increase with the use of 3 crystals, that would be good news...  8)   but I think it increases.
Gyula
Hi Gyula. thanks for reply. I tested and when I use one crystal current is 38 mA when I use three crystal the current is 33.4 mA !  so the brightness increased with lower current  ;D

NickZ

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Re: Dr Ronald Stiffler SEC technology
« Reply #584 on: July 16, 2018, 04:27:37 PM »
   Gyula:   I measured the current on my oscillator. Without the crystal it was 22mA, and with the crystal it was 52mA.   This is with the L3 on a load of 10 leds on an AV plug. This is with an 8v input.
   For some reason, now only the 7.2Mhz crystal is doing anything. No light with the other crystals on. 
Wireless near field distance is only about 1 cm away from the L3, as noticed on the led/av plug.