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motor keeping time with music

Posted: Sat Feb 14, 2004 11:43 pm
by Latta
I tried using sound senors to make music keep time with a motor. The only thing that happen was it produced a jerky motion, and was not very fluid. Does anyody have any suggestions? I'm trying to control a motor with an MP3 player so that it looks like it's keeping time with the music. Thanks

Re: motor keeping time with music

Posted: Sun Feb 15, 2004 2:24 am
by Edd
MAYBE YOU’RE USING JERKY MUSIC……(the devil made me do it)…surely I jest..he ..he.
Seems like the last sentences composition seems to be more in order with what you are trying to accomplish rather than the motor controlling the music, right? Also I think all of us could do with a bit more specific details on your attempted electro/mechanics. Like is the motor just a very lightweight unit that would not have a great amount of inertia/weight factor to contend with. Hopefully… Low Voltage DC drive? Sensors… how many and what is the mode of sensing?, …and they are sampling from the MP3 audio source, right ? any frequency determinate filtering of the audio source involved?...e.g. like in the manner of a Light Organ, wherein AF frequency spectra sampled/via/bandpass filters feed different colored lamps in frequency selective response to the music and modulate them with the AF’s amplitude variances.
If a DC motor and its drive electronics is involved, at an early stage, a PRECISE degree of capacitance filtering of the varying signal would be the first thing to experiment with, naturally, if excessive, the fluctuating drive level to the motor would be smoothed out too much.
Looking in a different perspective, a variance might be used in the manner of a motors fixed speed being diminished by electro or mechanical braking action, this typically could provide a greater and quicker response.<p>
73's de Edd
[email protected] .........(Interstellar~~~~Warp~~~Speed)
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;)<p>[ February 15, 2004: Message edited by: Edd Whatley ]</p>

Re: motor keeping time with music

Posted: Sun Feb 15, 2004 4:32 am
by Mike
Yes, I say put a capcitance across the motor, probably somewhere between 100uf and 1000uf<p>and good one Edd !!!! :) :) :D <p>-Mike

Re: motor keeping time with music

Posted: Sun Feb 15, 2004 6:57 am
by MrAl
Hello there,<p>If i understand you right, you're trying to
control the motor speed with the audio output.<p>It sounds like the motor is responding mainly
to the audio peaks. To get a smoother control
another idea is to compress the audio first.<p>Also cool would be to have two or more motors
that respond more to different frequencies
with blades that cross along the horizontal
thus creating unusual patterns as the music changes.<p>Take care,
Al

Re: motor keeping time with music

Posted: Sun Feb 15, 2004 8:48 am
by CeaSaR
I know a fellow who runs a Sound Company (does the PA work for LOTS of fairs on the East Coast and a number of bands - mostly country - Charlie Daniels is one that comes to mind immediately) and he used to have a bass driver composed of a motor and balanced hammers on the end of the shaft that struck a large sheet of ?plywood? or something like that. He said it worked great for really low frequencies, but was just too big to lug around. No idea what the driver was, but I think a frequency to voltage converter to drive a dedicated PWM motor controller would probably solve the problem. Yeah, it sounds like you are taking a round about way to accomplish your desired effect, however, the buffering and added drive capabilities would more than offset the aggravation of trying to be more "direct".<p>CeaSaR