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

Re: [TCML] BPS Testing



Hi Bart,

Maybe do a DFFT thing to find the base frequency of the signal of interest and then sample at the 2X Nyquist rate. A simple RC filter might also turn the very fast "spike" into a "bump" that would be easier for the toys to pick up out of the noise.

Just a thought...

Terry


bartb wrote:
Hi All,

Looking into the data that Excel could not port in seems to be quite a bit (~8 seconds missed). I therefore counted each break in the waveform browser out of curiosity.

I counted 998 breaks and the actual total time recording is 12.747 seconds. This works out to 80 bps, so it's still very consistent (reason I did this is that when I filtered the csv file in Excel, I used a quick means of doing so [equations and smart filtering to make quick work of 65000 rows of data]). So, this was a cross check (there's nothing like physically counting to be sure).

All is good.

Gary is certainly correct that the gap is chaotic. There are times when a break occurs right after a previous one and times when there is no break for quite some time. Looks like the average over all balances out nicely.

If you guys want, you can download the waveform browser (free download) and I can just view the actual data collection file or save your own csv or other types of data. That way you can see everything the way I see it. If interested, the waveform browser can be downloaded here: (quick install).
http://www.dataq.com/support/downloads/newwwb.exe

The file is here:
http://www.classictesla.com/temp/gap15-60-NST-3.wdq

You can then just open the file and view it for yourself (if desired). There is a lot of dead time in the beginning. I think I started the coil about 28 seconds after I started recording (I had a difficult time finding the plug in the dark).

This was a good bps test. Had the pc not lost the hardware device, I could have recorded for a good 5 minute run at this sample rate (which I still hope to do). I obviously need to lower the sample rate (sorry it's so high, I just didn't want to miss anything). I may try it next weekend on a pc with a real chassis and ground connection. If anyone ever buys one of the DATAQ acquisition devices, I recommend a serial port (stay away from the usb interface if possible). I'm using model DI-158/UP/HS.

Take care,
Bart



bartb wrote:
Hi All,

I continued BPS testing today. I paralleled two 15/30's after phasing for 15/60 power. I didn't want to change any coil parameters other than power and a single 15/30 would have been just too small for the cap size. I removed the safety gap and used 120Vac input via switch to keep as many variables out of it as possible (no variac, etc.).

I did have some problems with the pc loosing the usb hardware device. It captures data up to the point where the usb hardware device gets lost. I'm aware of this problem (as is the manufacturer). I recorded 4.5 seconds of run time (actually a little more but Excel maxes out at 65000 rows of data). I probably should have turned down the sample rate. Hind site.

Here's a gif image of 15/60 run. Dead time on left of image is the time it took me to run in the garage and turn on the coil.
http://www.classictesla.com/temp/bps_compress.gif

When I save the csv file, I set the marker just before the first break (so data to left is not exported). Here is a picture of the break area expaned with no compression.
http://www.classictesla.com/temp/bps_test_1560.gif

The Excel file identifying time stamps and break voltages:
http://www.classictesla.com/temp/gap15-60-NST-3.xls

The raw csv file:
http://www.classictesla.com/temp/gap15-60-NST-3.CSV


Ok, Javatc calculated 70 bps for this NST, cap size, gap, etc..

What I measured were 373 breaks over a time span of 4.542 seconds. So 82 bps.

Seems about right to me. I don't see a large variation in calculation to measurement.

Take care,
Bart

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla


_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla



_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla