Author Topic: Body Metronome  (Read 3431 times)

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Offline EEBlackSheepTopic starter

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Body Metronome
« on: December 10, 2011, 03:46:10 am »
I am a musician.  There is a metronome out called a body metronome and uses a vibrating clip rather than a speaker - so the musician "feels" the beat. *very* cool thing.  Anyways they are $120 and I can make one way cheaper.

I have a couple of eletronic metronomes with ear phone jacks.  These emit a square wave(ish) at 5Vpeak for about 5ms duration.  I also have scavenged a cell phone vibrator motor from an old phone that takes about 3.5VDC max.  I tried connecting the two thinking that the load from the motor would sag the voltage, but nothing happened.  So I am guessing one of a few things.  I need more current, I need a longer on time, I need a little less voltage.

So...  I am thinking I should have a sperate power source for the motor - a rechargeable lithium will do.  And use a transistor to control the power to the motor, and the transistor can be triggered by the metronome.  However, I am unsure about any supporting components or the right spec for the transistor.  Also I am unsure how I can increase the on time (although I am not sure if I even need it)

thanks for the help.
 

Offline Joshua

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Body Metronome
« Reply #1 on: December 10, 2011, 04:10:56 am »
I am also a very involved musician. I will be following this thread closely. This would also probably be great for my students who at the beginning have a hard time grasping the fact you have to play *with* the metronome. Sorry I don't have anything to add, but good luck and I will look forward to progress updates.
 

Offline robrenz

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Re: Body Metronome
« Reply #2 on: December 10, 2011, 04:12:42 am »
IMO the vibrator motor is not a good choice.  Too much time to accerate and decelerate, it would limit the highest frequency you could achieve.   A very small voice coil in a mini speaker might work, possibly with a properly sized weight added that would give a sufficient thump you could feel.  Others on the forum are more versed in giving advice on the electronic end of it.

Offline EEBlackSheepTopic starter

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Re: Body Metronome
« Reply #3 on: December 10, 2011, 04:15:43 am »
Well perhaps humour me and let me find out if this will work or not through experimentation.  Any suggestions on the control circuit?
 

Offline EEBlackSheepTopic starter

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Re: Body Metronome
« Reply #4 on: December 10, 2011, 01:27:15 pm »
These guys pulled it off at 100BPM - I only need 150 so I think its quite doable: 
 

Offline EEBlackSheepTopic starter

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Re: Body Metronome
« Reply #5 on: December 10, 2011, 01:44:43 pm »
He he - never mind - bought one for my android smart phone.  $2.93 - works just great. 

So much for the guess that it wouldn't work.  hah - naysayers.  Doom and gloom.  Reminds me of a song - "sunny side of the street". 

Time to go and play.
 


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