In article , "Dave Plowman (News)" wrote:
In article ,
ian field wrote:
A good clue as to whether its a piezo sounder is that some other
component would provide a DC path for the collector of the driver
transistor - maybe an inductor or just a resistor if its a real
cheapie.

Isn't it easier just to look at it? A piezo sounder looks nothing like a
moving coil speaker.


And sounds nothing like a moving coil speaker. I say,
throw a resistor across it and measure the AC signal voltage to
get something we can compute with.

greg