# Question on lvd, and load cell output

1. Oct 27, 2013

### jddj

Hello, I graduated last year for mechanical engineering and have a project that i am working on at home that i need some help on with the electrical part. what i am trying to build is a shock dyno, i need to measure force and velocity, i plan on using a lvt and a load cell unless someone has a better idea. my problem is i am not quite sure how to hook these components up to output to my computer. i am guessing i will need a DAQ module and maybe some other devices for signal conditioning. I have Simulink on my computer which i think i can output to? i do not have too much electrical knowledge and was hoping someone could lead me in the right direction.

Thanks

2. Oct 28, 2013

### meBigGuy

Can you speak a little more of your stimulus and the nature of the object and motion you are measuring.
F = ma or F=mv/t
When I think of shock measurement I first tend to think of the acceleration of a known mass to determine the force. But, that's just me. Or you can measure the force and acceleration to determine the mass.

Anyway. a little more information will help focus.

As for the interface, that also depends on the magnitude of the measurements you are making (which determines the available transducers) and the sample rates, number of channels, and accuracy you require.

EDIT --- is this what you mean? http://www.shockdyno.com/ or http://farnorthracing.com/autocross_secrets20.html

3. Oct 28, 2013

### jddj

thanks for the reply, my goal is to get a graph of velocity vs. force and from this i will be able to get the damping coefficient of the shock. I figured if i could measure these directly it would be the easiest. i have not decided yet if the shock dyno will be driven by a motor or manually, i have seen them done both ways on the internet. the one in your link is basically what i am aiming for but it looks like it is powered by a cylinder. i would like it to measure around up to 1000 lbs of force and around 10 inches per second for velocity. i guess i don't know enough about circuits or electroincs to know what i need for channels or sample rates.

Thanks for the help

4. Oct 28, 2013

### meBigGuy

I think you need to measure position also. (BTW did you notice there were two links)

Actually you are talking about a pretty ambitious sensor signal conditioning and data acquisition system.

You can get familiar with DAQ systems at National Instruments. Sketch out what it would take with their equipment.

For sample rate you need to think of how fast things are moving and how many data points you need.