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| Joined: | Nov 7th, 2007 |
| Location: | Alabama USA |
| Posts: | 127 |
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Yep, Minnesota and going against the fact that my arcade machines made it through last year in there, I decided to bring several things in as space would allow in our basement.
Could you suggest a method of transducer construction ? it's another first build.
First, apologies for the delay in response! Right! Well, I'll need to ponder this one further as it will get very deep in physics, because mass, and material really needs to be considered here!
One thing that comes to mind is a type of "strain guage" transducer. A strain guage is a device that uses a fine thread of conductive material; usually nichrome wire. A small current is passed through the wire, as the wire is suspended under a slight pulling pressure. This wire will react to temperature, or external force changes by changing its resistance. If the wire is pulled with more pressure than the original static pressure, the resistance will change, and the resulting current will change with it. That current is fed into an ammeter to measure the change. Inversely, if pressure on the wire is relieved, again the resistance will change, the the current changes with it. This will change will be shown on the ammeter in the opposite direction.
Now, lets say the wire is disturbed by an acoustical force placed perpendicular to the wire. This force will "push" against the wire, stretching it; or placing it under more stress. The resulting current will change, along with the modulations of the acoustic forces on the wire. Really, this is how a microphone works by changing acoustic energy into electric energy.
But if the wire is replaced with a human hair, we cannot pass a current through the hair. But we can measure changes at least in length by placing a DC current through a potentiometer feeding a voltage into an op-amp of very high gain. The potentiometer would be varied by mechanical connection to one side of the fork we were discussing before. The small variances from the potentiometer would create very large, measureable changes at the output of the op-amp!
This would be one way to create the transducer.
Regards,
Jeff