In Reply to: Darn it ! This shoulda worked ! posted by Andy G on December 06, 2001 at 17:23:43:
The circuit you've shown basically has 10 ohms or 30 ohms in series with a primarily capacitive device having more than 1K ohms reactance over much of the audio band. In laymen's terms what this means is that you have just no voltage division whatsoever, either way.Put that 7.5 ohm resistor across the piezo and the switched resistor network in front of it. That will give you a two-position variable attenuator. I prefer to use capacitors to attenuate piezo tweeters, but you can also use a resistive voltage divider as long as it has two resistors rather than using the load as the second one. In this case, your load is capacitive.
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