Piezo Stack Amplifier, 3 Channel, Open-loop Position Control

In open-loop, a piezoelectric actuator can reach its nominal displacement in approx. one third of the period of its first resonant frequency. The resonant frequencies for all our devices are provided for different loads, see specifications on the individual product pages. For loads in between, a linear relationship between the load and the resonant frequency can be assumed. Example: With 105 g load, the resonant frequency of the NanoPositioning linear stage NPXYZ100 in z-direction is 250 Hz. It can reach its nominal displacement within 1.3 ms. When the stage is excited with a sharp electrical pulse, the stages resonant frequency will be excited resulting in position overshoots with a damped oscillation. Hence, shorter electrical pulses may result in higher super-elevation, but not in shorter rise times.

Another boundary for fast open-loop operation is the current that can be provided by the piezoelectric amplifier. The diagram displays the max. sinusoidal frequency which can be supplied by the NPC3 and NPC3SG amplifiers as a function of the capacitance of the piezoelectric transducer and the voltage amplitude. For other models please see user manual for drive frequency curves.