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Re: [TCML] BPS Testing
I was looking at my input VA for the 140Vac situation. If I work the
math backwards for the bps measured, my calculated current would be 11.6
rms amps. Strangely enough, the expected output spark length equates to
1.42 x sqrt(11.6*240). Why does 1.42 sound so darn familiar? When you
first derived the JF formula, wasn't it 1.42? Probably nothing, but as
soon as I saw the value, it felt very familiar.
In Javatc in the Transformer section, there is an input for "ballast
current". It is meant to insert a measured value. If you insert your
measured input draw value here, it will override the transformer current
plate specifications and adjust for that particular current draw. So I
simply set this current value until my static gap section achieved the
measured 104 bps with my gap geometry (11.6A). At that point, I looked
at the spark length in the static gap section (57.2") and then found
57.2/sqrt(16.2*240) = 1.42 and that's when familiarity set it. Probably
Unfortunately, I didn't pay attention to spark lengths. Once I flipped
the switch to run the coil, I ran back in the house (turning off the
garage light in the process) and hit the record function on the pc (I
then watched events unfold in real time on the pc). But, I could "hear"
some "good" gap and spark firing happening. I'm certain about 50" was
real, but can't say if it reached 57" or not.
Today I ran the coil at 140Vac and retested bps.
I also measured input current at both 120Vac and 140Vac while running
During the 120V measurement, current fluctuated between 12.7A to 13.7A
= 13.2A average = 1.58 kva.
During the 140V measurement, current fluctuated between 14.6A to 15.8A
= 15.2A average = 2.13 kva.
For the BPS Testing, I ran similarly as before, except this time I got
rid of the switching power supply and simply installed some 9V
battery's on the board to power the light transducer.
The total recording time is 11.3263 seconds. Total breaks were 1176.
BPS is then 104. So still pretty low.
Photo of the setup:
Photo of the gap:
The sample rate was set to 2500/s, so time divisions are 0.008 seconds.
Here's the various files (windaq, raw csv, filtered bps excel file):
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