Referee Whistle: the Physics -- CONTEST!!
Phil Pilgrim (PhiPi)
Posts: 23,514
I came across this NY Times article about the whistle being used these days by referees. Most people are familiar with the classic whistle that has a little ball ("pea") inside, but refs don't use those anymore. Instead, they use a "pea-less" variety that still produces the classic vibrato via three tones that beat against each other. Here's a link to the whistle's back-story:
From the link:
It's always nice to see physics principles being applied to the design of something we would otherwise take for granted as being simple.
-Phil
From the link:
"A pea-style whistle gets its shrill from the movement of the small cork pea in its interior, which alternately covers and uncovers the hole through which air is released. This process produces a rapid alternation of sound and silence, the characteristic whistle vibrato until the pea gets stuck in the hole.
The Fox 40 Pealess Whistle is much like a harmonically-tuned instrument, because it produces three slightly different frequencies simultaneously. The different frequencies are superimposed on one another out of phase, and thus alternately reinforce and cancel out each other. The result is a loud, piercing vibrato that has no moving parts to get stuck."
The Fox 40 Pealess Whistle is much like a harmonically-tuned instrument, because it produces three slightly different frequencies simultaneously. The different frequencies are superimposed on one another out of phase, and thus alternately reinforce and cancel out each other. The result is a loud, piercing vibrato that has no moving parts to get stuck."
It's always nice to see physics principles being applied to the design of something we would otherwise take for granted as being simple.
-Phil
Comments
So much of what makes life great started out with someone's dissatisfaction with the status quo.
Let us all go forth and be dissatisfied.
Who wants to participate? In honor of March Madness, the game is afoot!
-Phil
Participate? Sure! Complete and compete...you never know.
It should probably be using a standard board (activity board) or at least standard audio circuit so nobody goes tweaking the passives for that "studio sound".
Probably something simple like a 3-5 second whistle blast. Start or end of period?
The program can be developed on any board. My personal vote in the poll will be according to how it sounds on an Activity Board, possibly driving a Veho speaker.
BTW, prize has been ordered from Amazon. 'Got one for myself, too, for kayaking (required by the Coast Guard). Pea-less whistles work better than the pea'd variety, should they get wet.
-Phil
Yeah, you're correct! My old eyes can't tell a 6 from an 8 on my iPhone!!
By the final WHISTLE of the Championship game??
Pea'd whistles need to be kept in a Pea coat to stay dry!
Activity board and a Veho are good for a sounding board (sorry).
(By the way, sorry for the sports references for all the hard-core engineers - I'm sure someone can translate for you)
I suspect the makers of pea'd whistles are starting to pea in their pods, now that the Fox 40 has gained traction.
-Phil
Classic Pea Whistle
Whistle tests.
-Phil.
Bogie's whistles is classic!