Dr Ronald Stiffler SEC technology

[gyulasun]

....
Here is a test picture from this computer--

Hi Lidmotor,

An oversized picture causes the text to widen automatically in a post too but only in case you do not use
carriage return (Enter) after ,say, 7-8 words, this will make the text a column-like format.  So whenever you
make a post in a thread which is already too wide by a high resolution picture, then you can make it easily
readable by reediting your text to a narrower series of lines, all this within 12 hours after the posting time.

This forum software sucks in this respect and Stefan Hartmann should resolve such issues now that he is going to
change the forum software he has been postponing for ages now...

The Tesla picture you have uploaded to test one of your computers is ok by size because it has pixel number of
512x655 and the 512 number (the horizontal pixel number) can go as high as about 900 with the present forum
software without causing thread widening.

If you open a picture in an editor like Paint (built into Windows) before uploading to your post, you can see the
number of pixels in the very bottom line in the editor and using the Resize feature you can adjust it.As Slider
mentioned above, the width and resolution of one's PC monitor also counts in a certain extend but generally
many forum members 'suffer' when a too wide picture is attached to a post in a thread.

Gyula

[Slider2732]

Oh and just to explain my posts following the supersized pic...yes I too hit enter after several words, as Gyula mentioned.
For all pics, I open them in GIMP, resize to a width of 640 and save out again. Am running Linux Mint.
Can Peter over at Overunityresearch be approached to share his code ? because the forums have a very similar layout. Both seem to be using code from Simple Machines. Over there, each pic is a large thumbnail that can be clicked for larger.


Here's where the sig gen is up to. Am wiring it up now. At some point it'll get a case

[Lidmotor]

Gyula and Slider---Thanks for the help on the post size issue.  I will get there but it takes me awhile to learn certain things.

-- Lidmotor

P.S.-- Slider that little signal generator looks really cool!  I hope it works.  If it does I guess my next project might be that one.  I can team it up with my old computer O scope and maybe get something meaningful done.

[Slider2732]

If you're not used to editing pics then it can seem a bit daunting. It really isn't a trauma, after the first couple of times. Oh, your camera may have resolution and size settings, which may be in the menu's if it's a phone.   


The build has been interesting, shall we say.
It's comprised of the AD9850 module, an Arduino, a screen and a rotary encoder. The bits laid out well on the perfboard.
Schematic that has been followed is here:
http://arduinotehniq.blogspot.com/2015/03/signal-generator-with-ad98509-and.html

I soldered everything up and plugged in the USB cable.
Smoke escaped from the Arduino diode !!!!
It wasn't just a whimpish puff of a slow fail either, the damn thing went off like it meant to fail properly !
I disconnected power to the screen and AD9850, then connected directly to the +5V and GND of the Arduino....life.
So then I connected the screen, it came on fine and showed the code running.
Twiddling the encoder works fine, values go up and down and the push button bit works fine too. As you can see in the image below, it was set readily to 13.6MHz (I had also changed the code because it had said 'Mhz' originally).
But connecting the VCC of the AD9850 powers everything off. That shorting condition will have blown the diode under the Arduino.

Am now going to power the AD9850 on its own and see if the red power LED comes on.   

[gyulasun]

...
Edit: ok, i just finished winding the new magnet wire coil, it is bifilar 24awg. magnet wire, strands are in parallel at 300 milliohms and 31 grams weight, which includes a little electrical tape, that is used to tighten the windings together.

Hi SkyWatcher,

Okay, so the paralleled wires now give 0.3 Ohm DC resistance for the primary air coil. This means the dissipated loss in the primary will certainly be less than earlier for the 0.69 Ohm (calculated by me) single wire winding, considering similar collector current.

Here I have to tell you I made a calculation mistake for the dissipated power for the single wire primary coil in my post #239 where I got a rather high loss at the 11.2 mA collector current: this was only 0.0912 (and not 91.2) mW, sorry for the mistake, I rang the alarm unfounded.   

Because you have increased since then the supply voltage to 16 V and the collector current was 21 mA, the loss for the single wire primary may have been 0.021² * 0.69 = 0.304 mW. If you now keep the supply voltage and current the same for the paralleled two wires in the new primary coil, then the dissipated loss in the paralleled wires would be 0.021² * 0.3 = 0.132 mW only.

So all these mean that such low primary coil dissipation is negligble versus your earlier 336 mW total input power (for the single wire primary coil case).  Probably you will not see much improvement in brightness with the paralleled wire primary coil versus the single wire one, provided you insure identical input power for both.

Gyula