Mission Statement - De-Spinning the Pro-Taser Propaganda

Yeah right, 'Excited Delirium' my ass...

-------------------------------------------------------------------------

The primary purpose of this blog is to provide an outlet for my observations and analysis about tasers, taser "associated" deaths, and the behaviour exhibited by the management, employees and minions of Taser International. In general, everything is linked back to external sources, often via previous posts on the same topic, so that readers can fact-check to their heart's content. This blog was started in late-2007 when Canadians were enraged by the taser death of Robert Dziekanski and four others in a short three month period. The cocky attitude exhibited by the Taser International spokespuppet, and his preposterous proposal that Mr. Dziekanski coincidentally died of "excited delirium" at the time of his taser-death, led me to choose the blog name I did and provides my motivation. I have zero financial ties to this issue.

Friday, January 4, 2008

On the subject of "...continuous duty cycle..."

On reviewing the Ruggieri controversy surrounding the taser waveform, it becomes clears that Taser is also claiming an escape clause under the topic of 'continuous duty cycle' because the high frequency (50 or 100 kHz) component is cycled on and off with a relatively low duty cycle.

But the X26 waveform is also periodic at 19 Hz (the M26 is similar) and Taser recommends (but does not limit) the duration of the application to five seconds. There have been cases where the torture was applied for durations approaching three minutes.

So the overall taser waveform (at 19 Hz) is continuous 100% duty-cycle for as long as the trigger is held down. And it appears that even Taser admits that these frequency ranges (19 Hz and harmonics) are far more safety-critical than the higher frequencies they keep going on about (50 or 100 kHz).

It would be fair for Taser to claim that the 100 kHz pulse at the leading edge of the X26 DC pulse is of a very low duty cycle, but it is not fair to ignore the 19 Hz component that is continuous duty cycle for as long as the trigger is held down and the batteries hold out.

Essentially, they're denying the existence of the 19 Hz component for purposes of calculating safety margins.

Smells like a huge error.

All because they apparently failed to perform a Fourier Analysis on their taser waveform.

PS: Watch out that when they finally do provide this information that they don't square the currents to calculate power (or energy) because by such a trick the higher peak amplitude of the high frequency leading edge will be given a boost while the lower peak amplitude of the DC component will be minimized. In short, make sure they keep the vertical axis as current (not power, not energy). We want the frequency spectrum of the current.

PS2: They might also try to slip in a log scale for the horizontal frequency axis so as to spread-out the lower frequencies (thereby reducing the amplitude values per frequency bin). Don't let them.

No comments: