6 Starting and O
38
Version: 1.1.0
PZ259E
P-88x/P-08x Piezo Actuator
6.2.4
Calculating the Forces that Occur During Dynamic Operation
Calculate the dynamic forces acting on the unilaterally clamped piezo actuator during
sinusoidal operation at the frequency f using the following formula:
F
dyn
= Dynamic force [N]
m
eff
' = Effective mass m
eff
(approx. 1/3 of the mass of the piezo actuator) + additional
load M [kg], see also "Calculating the Effective Mass" (p. 36)
Δ
L = Displacement in the application (peak-to-peak) [m]
f = Frequency [Hz]
Example:
The dynamic forces at 1000 Hz, 2
μ
m displacement (peak-to-peak) and 1 kg
effective mass are approximately ±40 N.
6.2.5
Calculating the Power Requirement for Sinusoidal Operation
Calculate the average current requirement for sinusoidal operation using the following
formula:
Calculate the peak current requirement for sinusoidal operation using the following
formula:
Variable
Description
Notes
I
a
Required average current of the
amplifier (source / sink) [A]
It is essential that the power supply can
supply enough current.
I
max
Required peak current of the amplifier
(source / sink) [A]
The provided peak current depends on
the internal storage capacity of the
amplifier.
f
Operating frequency [Hz]
Details on the operating frequency see
"Overview of Limiting Factors" (p. 35).
C
Capacitance of the piezo actuator
[F (= As/V)]
See "Data Table" (p. 47) for the small-
signal capacitance of the piezo actuator.
For large-signal conditions, a safety
factor of 70 % should be added to the
small-signal capacitance.
U
p-p
Operating voltage (peak-to-peak) [V]
Voltage difference between positive and
negative peak voltage