[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Re:High speed Tesla spark photographs - A summary of developments



Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx>

Hi Peter,

At 07:33 PM 10/5/2006, you wrote:
.......
Starting to work on my new "secret weapon" soon too.

:-)))))

Terry has made up his own superfast rotating mirror unit (10,000 RPM) and is also getting great results. He is planning a voltmeter/current meter for his unit as below.
.............
Peter

It actually goes to near "50,000 RPM" with the 300A(!) stall current motor being run at "only" 2X voltage :o)) But I only take pictures at around 10,000 RPM. The motor is really scarry at 50,000 =:O I ran it up there once with the mirrors and all (NOT the camera!) and it was sort of like a jet engine!! But it held together fine!! I may have bent the motor shaft "just a little" pressing the mirror block on it at 4000 pounds and tapping with a hammer... Like the Egg of Columbus thing... It just "finds" its center highest "Q" of rotating mass...

I removed the safety Lexan shield now since it "got in the way". The camera lens is now very close to the spinning mirror:

http://drsstc.com/~streakcam/instruments/StreakCamera2-02.JPG (mirror "was" spinning there, but "cheap cam" is "fast" and froze the image)...

http://drsstc.com/~streakcam/instruments/StreakCamera2-01.JPG

If it blows the old camera lens out, I could get one of these ;-))

http://www.olympusamerica.com/cpg_section/product.asp?product=1268


I have not done much for a long time now..., but I did manage to order parts and started work on the streak camera "oscilloscope" today :-))) Here is what I have so far:

http://drsstc.com/~streakcam/instruments/BarScope-01.JPG

The "Light Bar" has 24 high brightness LEDs. Three green ones define the top, middle, and bottom of the scale. 20 red LEDs fill in the bare graph scale on the +-5 volts at 0.5 volt increments. There is an extra green LED which will have the 100.0kHz calibration scale function. The holes were drilled in 0.75 inch angle aluminium to 0.192 inches and the LEDs are "pounded" in with a bit of 1/4 inch tubing "very tight". The LED spacing is 0.375 inch. The front was sprayed with matt black. The assembly is 9.75 inches long.

A proto board will hold the LM319s (all of them "cost less" than just "one" of the green LEDs!), the +-5V regulators, and the LMC555 circuit. I need to figure out how to do the voltage divider array and the LED drop resistors. That will be easily "creative" ;-))

I have two 9V batteries for +- 9V and 4 AA batteries to drive the LEDs. There is a block for the +-5V input and a power switch. I will sandwich it between copper FR4 board material cut to suit for HV/RF shielding. Running the circuit should not be any problem at all considering what I have done before ;-))

http://hot-streamer.com/temp/DaveTest-82.jpg

http://hot-streamer.com/temp/DaveTest-83.jpg

http://hot-streamer.com/temp/DaveTest-84.jpg

It should be able to sit on top of the toroid will a little aluminum foil field control stuff. Almost any CT can go into it. I have TI ICs which should go to 1MHz, and if they blow, they are $0.20 each... I will sprinkle in caps and 24V TVSs as needed... Should be cool!!!

Cheers,

        Terry