Testing the TK Tar Baby

[TinselKoala]

 

[TinselKoala]

I see that there are a lot of people lurking, as usual. I hope we are providing you all with some amusement. It is better than reality TV but probably not as much fun as National League Hockey.

@neptune..... if you are out there, I must congratulate you on your early perspicacity. It's too bad that YKW didn't deign to answer your questions about the use of the 555 timer.

I can assure you that your surmises about the 555 timer not being able to make the bipolar pulses, as well as your thoughts about extended continuous oscillations or very slow switching using, e.g. relays, are also perfectly correct and on the money.

[TinselKoala]

The scope shots shown in this forum post are interesting. Look at them in chronological order (the bottom one comes first) NOT the way she implies at the top of the post. The BOTTOM one,SCRN0235, comes first in the time sequence.

Compare, contrast, discuss. Attack, bloviate, bury.

I think we are witnessing a mosfet being tortured to death. It's too bad the Drain trace is.... mentioned in the "caption".... but not shown on the traces.

http://www.overunity.com/10407/rosemary-ainslie-circuit-demonstration-on-saturday-march-12th-2011/msg278651/#msg278651

So... If the circuit is being operated sometimes with a bad Q1, as it seems from some of the scopeshots, where is the high load heat coming from if the "off" or Gate LO oscillations don't pass much current and the DC current is nil during the "on" or Gate HI periods?

[MileHigh]

TK:

I assume that you took that picture.  Very impressive.  I would have poked a hole in a piece of cardboard.   

I've never been a fan of Rosemary's scope captures.  It looks like Q1 MOSFET is not switching on in some of the captures.  You can also see robust gate drive signals that are high in voltage and flat.  So who knows?  What the specific setup was for each capture is possibly unknown.  Personally I don't know if much reliable information can be extracted from them.  For example, you have captures with a robust gate signal and captures with a very corrupted gate signal and there is no attempt to explain that.  It's just like the 'missing' CVR current when Q1 is supposed to be on.

MileHigh

[TinselKoala]

TK:

I assume that you took that picture.  Very impressive.  I would have poked a hole in a piece of cardboard.   

MileHigh

Thanks... yes, I took it yesterday or the day before, it's all kind of blurry lately.

I'm trying to get my solar technique down for the Transit of Venus on the 5th of June. If I can make a timelapse of that I will be very happy indeed.

It looked a lot better in the eyepiece, and that image is just a single frame, not heavily processed and stacked from multiple frames like most of my AP work. I just haven't had time to work on it, but I'm sure I can get a better final image from the 50 or so frames that I shot. I put a video on my YT channel showing the "observayurt" and the telescope/camera. The video was shot just before I took the images of the sunspot.

Actually, if you can get the right kind of hole in your cardboard, you can make a quite good solar viewer out of a big cardboard box, using the 'pinhole camera' layout. A tiny teeny hole in thin opaque material, with perfectly round edges. You could try heating up a pin and poking it gently through a bit of black plastic, then putting that "hole holder" into a larger hole in the cardboard box, and project against a white screen on the other side of the box, and provide a viewport (facing AWAY from the SUN and towards the screen on the rear of the box. Or you could even use a piece of tracing vellum and make a "rear projection" solar pinhole camera. I might try that !

(This is why I lol and lol whenever YKW complains about my lousy photography. I actually do understand a little about the subject, and when it's important to me, I can take properly exposed, high resolution, absolutely stable images, videos, timelapse, highspeed.... you name it, if it's important I can do it. Do you need high speed high contrast Schlieren video photography of 3000m/sec underwater shockwaves? I can do that. Do you need air-to-air aerial photography of your new aerobatic airplane flying upside down? I can do that. Do you need an extreme blow up of a grainy monchrome microdot showing your enemy's dirty underwear? Sure, no problem. Long exposure deep sky astrophotography is a piece of cake compared to some of the photography I can do...if it's important enough.  But shooting impromptu documentation of demonstrations designed to entertain a small audience and to educate an even smaller one... heck. I'll hold the camera under my chin, dim the lights to encourage hallucinations, reduce the HD originals to .flv, show the dog and the NERD preventer, all of that. If someone doesn't like it, they really should take the issue up with whoever it is that forces them to watch my videos. And if they fail to Get The Message, they only have their early educational choices and experiences to thank for that.)