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lilrags16
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Help understanding chopper slots to hz...

Thu Aug 21, 2014 5:21 am

Hello, I would like to build a mini siren. I need help finding out how speed, chopper slots effects the sound.
Thanks
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holler
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Re: Help understanding chopper slots to hz...

Thu Aug 21, 2014 10:09 am

https://airraidsirens.com/forums/viewtopic.php?p=15565

Remember the higher the speed the higher the pitch.

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lilrags16
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Re: Help understanding chopper slots to hz...

Thu Aug 21, 2014 1:22 pm

holler wrote:https://airraidsirens.com/forums/viewtopic.php?p=15565

Remember the higher the speed the higher the pitch.
Thank you. Still getting use to Tapatalk(can't search that well)
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Re: Help understanding chopper slots to hz...

Thu Aug 21, 2014 7:12 pm

If a chopper has n ports, it will produce n pulses of air for every revolution. Multiply n by the number of revolutions per second and you have frequency in Hz (pulses, or cycles, per second). Since most motor speeds are given in revolutions per minute (RPM), you must divide motor speed by 60 to get revolutions per second. The whole equation is:

Frequency (Hz) = (RPM / 60) x n
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Re: Help understanding chopper slots to hz...

Fri Aug 22, 2014 3:07 am

landmobile wrote:If a chopper has n ports, it will produce n pulses of air for every revolution. Multiply n by the number of revolutions per second and you have frequency in Hz (pulses, or cycles, per second). Since most motor speeds are given in revolutions per minute (RPM), you must divide motor speed by 60 to get revolutions per second. The whole equation is:

Frequency (Hz) = (RPM / 60) x n
But bigger the slot the louder??
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Re: Help understanding chopper slots to hz...

Sun Aug 31, 2014 2:36 pm

lilrags16 wrote:
landmobile wrote:If a chopper has n ports, it will produce n pulses of air for every revolution. Multiply n by the number of revolutions per second and you have frequency in Hz (pulses, or cycles, per second). Since most motor speeds are given in revolutions per minute (RPM), you must divide motor speed by 60 to get revolutions per second. The whole equation is:

Frequency (Hz) = (RPM / 60) x n
But bigger the slot the louder??
Larger slots are one of the ways you can increase airflow. Increased airflow will make the siren louder, however larger ports might not always do this as the intake size can limit airflow as well.

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