14 Nov
2008
14 Nov
'08
9:45 p.m.
Date: Sat, 15 Nov 2008 11:51:35 +1030
From: Matthew Smith <matt(a)smiffytech.com>
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.
very cool. do you have somewhere that you could post a picture of this thing? i'd love
to see it!
What I was wondering was whether end frequencies
coincided with any
musical notes.
not in the western equal-tempered scale, anyway.
see http://www.phy.mtu.edu/~suits/notefreqs.html
cheers!
--
.pltk.