On Fri, 9 Feb 2001 12:56:14 -0500, you wrote:

>Yes, both sine waves.  I intend to filter the driving signal to clean up=
 the
>40KHz signal into a pure sine wave.. The next question is, will an =
ultrasonic
>transducer respond to 40KHz sine just as well as square wave??
No - you will get less output. US transducers and piezo discs are
essentially capacitive, but also have strong mechanical resonance
effects, which combine to produce some strange electrical
characteristics. Using an efficient squarewave driver stage, and
measuring the DC into it will be by far the easiest way to measure
transducer input power (which of course will often have a somewhat
nonlenear correlation to output power)
>Chris~
>
>Olin Lathrop wrote:
>
>> > In the mean while, I discovered in reading that if I take the RMS of=
 the
>> > volts and current, multiply them together, then multiply by the cos =
of the
>> > phase angle, I will have real power.
>>
>> True, but this assumes that both the voltage and current waveforms are
>> sinusoids.

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu