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, April 18, 2008

Duty-cycle of 19 Hz component = 100%

"LEVELS OF SHOCK: The Taser X26 puts out 2 milliamperes [("average"), or 151mA RMS] at 19 hertz. The gun packs its current into 100-microsecond pulses, so it can capture muscle with lower current than if it had been delivered as a sine wave, as the rest of the chart shows."

Any complex waveform can be reduced to a series of sine waves. And a series of sine waves can be combined to produce any complex waveform. That's about all you need to know about the Fourier transform. This transform isn't just a math trick for representation and analysis; the relationship between the time domain and the frequency domain is perfectly real. These frequency components actually exist and will interact with whatever they meet.

What this means is that if a certain waveform is periodic and repeats at 19 Hz, then the frequency component at 19 Hz is CONTINUOUS 100% DUTY CYCLE at that frequency. Especially if the waveform is offset from zero (as is the X26). Although the waveform may be a pulse of current that lasts only about 100 microseconds, the frequency component at 19 Hz is a perfectly normal sine wave at 19 Hz.

Taser's specifications for the X26 waveform are 19 Hz, 2mA "average" (and 151 mA RMS according to the older specification sheets).

The 19 Hz component is CONTINUOUS 100% DUTY CYCLE during each 5-second cycle.

Keep this (the low frequency and continuous 100% duty cycle) in mind when fitting the taser waveform specifications against the applicable safety standards. Don't be misled about the 100-microseconds when considering the X26 waveform.

The older 1999-era M26 "advanced" waveform was quite different. It was a nicely damped burst of 50 kHz so that it's primary frequency component was quite likely at that frequency. The newer 2003-era X26 waveform is quite different in that the primary component is a DC pulse repeating at 19 Hz which results in a primary frequency at 19 Hz. They're totally different waveforms.

I don't understand why they switched from a low duty cycle (safer) high frequency (safer) waveform with the 1999-era M26, to a continuous duty cycle (more dangerous) low frequency (more dangerous) waveform with the 2003-era X26. Apparently they walked away from a couple of safety factors for a stated 5% increase in their so-called Muscular Disruption Units.

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