Mission Statement - De-Spinning the Pro-Taser Propaganda

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

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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.

Saturday, May 3, 2008

Forgetting Fourier are we ?

I've mentioned this before and it's time to mention it again.

Taser makes much of the short duration of the individual pulses that form the 'taser' waveform. Each pulse is only about 100 microseconds and 'therefore the heart cannot possibly be stimulated blah blah blah...' You will see this same argument in many many places.

Although this logic might apply to the older M26 model (introduced in 1999), the newer X26 model (introduced in 2003) has a significant DC-offset component in each pulse. This asymmetric pulse in the X26 waveform results in the primary frequency being related to the Pulse Repetition Frequency of the waveform (19 Hz), not the high voltage arc phase at 100kHz.

(See older posts such as [LINK] for backup on this information.)

Taser has as much as admitted all this up to this point. They list the frequency of the X26 as being just "19 Hz". But they also continue to justify the safety based on the short pulse width. They are still using this argument. Ah, excuse me. That's a discrepancy.

Let's review quickly:

The X26 waveform is a series of very short DC-offset pulses, and those pulses form a waveform that is primarily at 19 Hz. I believe that we're all in agreement up to this point. But 19 Hz (and harmonics) components of the X26 waveform are continuous 100% duty cycle for FIVE SECONDS. That step is almost common sense.

So what happens to their argument about the short pulse width? Perhaps it applies to the older 1999-era M26, but the argument appears to be stale with respect to the X26 model introduced in 2003.

Is this a real problem? You decide: [LINK] Pay attention to the direction of the curve starting in 2003. But I certainly admit that there may be other factors at play - and it might just be a coincidence.

This is why we need some organization like CSA (or UL in the USA) to get involved.

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