Bob Masta
Guest
|
Posted:
Wed Nov 23, 2005 5:35 pm Post subject:
Re: interesting sounding ultrasound |
|
|
You have two issues here: Generating the electrical signal,
and turning it into sound. To create the signal, you can use
any of a number of voltage controlled oscillators (VCOs) and
use a low frequency sine wave as the control voltage. That
will cause the VCO frequency to slide up and down like a
police siren, etc. Note that VCOs tend to have non-sinusoidal
output waveforms, typically ramps or square waves with lots
of harmonics.
The big problem is converting this to sound. For near-audio
frequencies (say, 20 kHz-40 kHz) you can try plastic piezo
horn tweeters. Many have strong output in this range, but
you will not get a flat frequency response... lots of huge
dips and peaks. But its cheap enough to try.
For higher frequencies, transducers tend to be tuned
to specific ranges. You could warble a little within a
given range, I suppose.
If we knew what you plan to do with this, we might
have more-specific suggestions.
Best regards,
Bob Masta
dqatechATdaqartaDOTcom
D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Home of DaqGen, the FREEWARE signal generator |
|