Dr Ronald Stiffler SEC technology

[NickZ]

   Slider:   Today I'll be picking up two different DC to DC step up converters. So we'll see how their outputs compares to your converter, as far as signal noise goes.

   I found the problem with not having wireless effects. It was just a bad diode in the loop used on the leds bulb. Now it works, and has a near field effect, although somewhat limited in gain.
   I also can light the 10 led bulb by capacitance, which was what I could not do before.
   So, in moving forward with this project I will be using a higher powered transistor that can handle the 35v that the converters can provide.
   Gyula:  I placed a resistor on the input to the oscillator circuit, in line with the 220 choke that is connected to the transistor. And now the circuit works (all night long), and does not overheat the transistor. However, the output gain is restricted, as compared to before the resistor was placed. That was to be expected, as any resistor is going to lessen the output by wasting the tiny bit of input juice, as heat. I haven't finished with these tests yet, once I do I'll let you know just what value resistor works best at what voltage levels.  But, I need the DC to DC converters for those tests.
   I also added a puffer cap of 47uf 100v, across the diode loop that's on the led board.  It does helps to brighten things up a bit.
   The best way to go for varying loads, is with a controllable trim pot on the base, and on the transistor's control/emitter, also.

[shylo]

Slider,
So the two positive diodes coming off the leads of the 75 turn coil (paralleled) are connected to the negative of the LED?Which is only connected to one end of the floral wire?Sorry just a little confused.Thanks artv

[erfandl]

Gyula - Many thanks for the tips.
Will try the 9V battery and look into the exact terminations. All I usually see is 'into a 50ohm load' and have no real idea how the load can be exactly terminated in that way. It's all new, apologies for that.

TK - OMG, as they say, yes of course. The scope is usually over at the usual bench, but I tend to move it to the far cleaner table for vids etc. The usual scope lead was over at the other bench, so I grabbed another and...didn't check whether it was on 1x or 10x


All - Found something of possible interest, which I would have thought would have reared as a fault or feature, but haven't seen it mentioned. The Dr. Stiffler type L3, with 2x AV plugs, an LED and length of floral wire can be used as a tester for mains wiring continuity.
The circuit is shown in the video and there is a positive reaction with wood, believe it or not. Maybe it's because of the humidity here in Oklahoma, but the thing has some very strange properties.

https://www.youtube.com/watch?v=c4hCiUUcZ18

Hi slider. Thanks for sharing video. I think if you using germanium diodes like 1N60 or AA119 get better result.

[gyulasun]

Hi Itsu,

Regarding your differential voltage measurement across the middle coil in Reply #590: the waveforms are quasi identical, the 1 V difference is very small with respect to the 43-44 Vpp amplitudes. I believe the small decrease in brightness you notice due to the probes connection may happen because the differential probe capacitance may detune the middle coil. 
I cannot guess why the Math trace goes negative, a crazy idea would say: flip the AV diodes polarity going to the middle coil and see then whether it changes to positive or remains negative?
Regarding your 1 Ohm csr measurements (when run from the oscillator) and also with swapping the output and input coils (when run from the FG): it comes that my thought to blame the small difference in input and output coils inductance would not explain the around 5 V change on the 1 Ohm when you remove or attach the output coil/LED combo. I still think though that the answer may still inherently be in the tuning of the coils, perhaps try to use a small piece of powdered iron RF core and approach it to each coil to reduce their own resonance and see any change in the 5 V issue. Of course, when you have time and the mood because this is not so important at this time and maybe it will not be. But it is still good the Math output value does not change when removing the 3rd coil/LED combo.   Thanks for all your efforts.
Gyula

[gyulasun]

Hi TinselKoala,  thanks for the info on the 3 V amplitude test signal for this scope type. A 30 Vpp amplitude would have no sense.

Hi Slider,

I did some search and came up with a approximate schematic on the output circuit of the AD9850 chip, you can see it as the last picture in the vertical picture icons on the  left side at the seller Amazon site:https://www.amazon.com/HiLetgo-AD9850-Generator-0-40MHz-Equipment/dp/B01J7XPWNU/ref=sr_1_2?ie=UTF8&qid=1531858422&sr=8-2&keywords=hiletgo+dds+ad9850+signal+generator+module 
So it turns out there has to be at least one 200 Ohm chip resistor on Pin 20 or 21 to the negative ground and a second 200 Ohm chip resistor directly across the sinewave RF output also to the ground.

Switch off the supply voltages and measure with an Ohm meter across this output, you may find either around 100 Ohm value or around 200 Ohm value.  For the 100 Ohm case the two 200 Ohms are in place these terminate the output and the input of a low pass filter you see in the schematic I refer to above (the input of the filter is driven from Pin 20 or 21 which are the outputs of the Digital to Analog converters).  If you find around 200 Ohm across the sinewave output then this output is probaly not terminated by 200 Ohm internally, in this case your generatour output impedance is around 200 Ohm and you need to use a 200 Ohm chip resistor to terminate it if your desire is to flatten the output amplitude response you objected in the board test video.  Of course the use of the 200 Ohm termination involves halving the output voltage amplitude as is always the case with generator outputs when they are terminated by their own internal impedance (resistance).   
This is shortly for you... 

Gyula