[LAU] [Slightly OT] 312.5Hz

[Matthew Smith]

Hi Folks

Slightly off-topic, but does anyone here know any audio significance of 
312.5Hz?

I have here a module from a piece of equipment dated back to 1968.  It 
consists of a 4-pole, 50Hz motor, a printed disc, a lamp and a 
photocell.  The printing on the disc (rotor) is a wiggly line of 
changing frequency which - according to the disc - represents a signal 
between 312.5Hz and 3kHz when spinning at 1500rpm.  You light the lamp, 
spin the motor, then amplify the signal from the photocell.

I've decided to use this as a tone source, replacing the filament lamp 
and photocell with an LED and LDR, or possibly a phototransistor.

What I was wondering was whether end frequencies coincided with any 
musical notes.

Cheers

M

-- 
Matthew Smith
Smiffytech - Technology Consulting & Web Application Development
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