Shaker table calibrator

[Jaguarjoe]

I am building a small shaker table from a nice sub woofer and other junk err... stuff.
I am trying to figure out how to make an accurate vibration sensor to use as a calibration "standard". My first plan was to use a10 turn pot with the shaft attached to the platform through a small pulley.
The last place I worked had a shaker and had a Kistler accelerometer and a double integrator but that's a tad pricey.
Any ideas?

Thanks!

 

[MrAl]

Hi,

Plan on experimenting with non Newtonian fluids?

How about a small reflector with photo detector of some sort

 

[alec_t]

A cheap piezo disc with an inertial mass attached (though accuracy/repeatability is dubious)?

 

[unclejed613]

you could use a dual voice coil speaker. the second voice coil would provide the acceleration information

 

[alec_t]

.....perhaps add a coil to your existing sub-woofer?

 

[Jaguarjoe]

I never knew there were dual VC speakers. This sounds like a plan.

 

[canadaelk]

How about a non-contact Hall-effect setup? E

 

[cowboybob]

Using a pot might introduce unacceptabe wear issues.

Perhaps a variable inductor tuner element from an old car radio? Or a variable cap from a similiar device.

Either one controlling the frequency of a simple oscillator circuit whose output is fed to an appropriate opamp 2nd order bandpass filter. The output could be rectified (and filtered) giving a repeatable DC value.

Obviously not linear, but that could be dealt with a number of ways, if needed.

 

[Mr RB]

A $5 accelerometer PCB with 3 analogue outputs.