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air raidsiren help? Answered

http://www.youtube.com/watch?v=agejuU2rYDs


please help me make one of theese and find where to buy the motor! i made a video too

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Have you tried websearching "how does an air raid siren work"? (Actually, much like other mechanical sirens...)

For testing purposes, almost any motor which will spin the rotor and fan at a suitable speed should work. Hand-cranked versions were used on early fire engines; I think they used a gear or pulley drive so the siren mechanism spun faster than the handle did. And the classic "siren whistle" toy is a simple version of the same mechanism (using air pressure from your blowing into it to both spin the disk and provide the pressure for the sound).

Of course this assumes that the siren mechanism itself is built correctly and works. If it isn't producing sound when you spin it, that would suggest that either there isn't enough air pressure being developed or that the gates which produce pulses of air as it rotates aren't sealing tightly enough or opening sufficiently.

As noted on some of the websites: The classic siren mechanism poses severe hazard of amputation if you poke a finger at it incautiously. Be careful!


I'm not prepared to download a mystery video - what is the question?

L

If you'll repost as an audio only file, I'd be glad to listen to it and give you feedback. till then I'm game off.

You would probably get more responses if you just typed your question.