Q: How to select an Actuator and Driver?

Selecting an Actuator and Driver

The application will always define the PZT and driver necessary. There is no universal PZT appropriate for all cases. As such, the user must evaluate the needs of a given system and find the PZT and driver that match these needs as well as each other. To determine the proper actuator and driver, here are a few helpful questions to consider:

1. What is the necessary shift/stroke for the application?

2. What forces will be generated by the PZT action?

3. What is the static preload on the PZT?

4. What external mass is acting upon the actuator?

5. At what frequency does the system need to be modulated?

6. What is the necessary displacement at the modulation frequency?

7. What is the desired maximum frequency at the maximum displacement?

8. How fast must the actuator act (i.e. fall and rise time)?

Not all of these questions may be applicable for a given application. For instance, if the system is to be a precision position or low dynamic system, then the first 3 questions would be most applicable as the actuator would not be modulated. If, however, the interest was for a system with dynamic operation, questions 4 - 8 will help select the appropriate driver (by calculating necessary Imax and Iave values).

When selecting an appropriate driver, keep in mind that less is more, as overdriving a PZT can damage it. The driver should match the voltage requirements of your PZT and no more. Do not use

a driver that outputs significantly higher voltage than the PZT is rated for. A properly matched PZT and driver will help increase the efficacy of system operation as well as its lifetime.