User Manual

Page 17

Figure 15. Magnitude response of R-C filter

Figure 16. Phase response of R-C filter

Figure 17. Magnitude response shown as log/log plot

Frequency

Response

This is illustrated in the

following example graphs.

First, a lin/lin plot is

shown (Figure 15, linear y-

scale or amplitude, plotted

against linear x-scale or

frequency) with the

corresponding phase plot

(Figure 16) also shown in

lin/lin form. Following

these is a log/log plot

(Figure 17), which will be

dealt with in a little greater

detail.

Note that the phase curve

indicates that at very low

frequencies, the observed

voltage will show

significant phase deviation

from the source (limiting at

-90

or -π/2 radians at "dc"

or zero Hz). The significance of this effect is great if the piezo film element is to be used as part of a

control loop.