A piezo controller or driver is used to control the motion of a piezo positioning device. There are open and closed loop controllers. Open-loop controllers are often referred to as piezo driver or even piezo power supply. Closed-loop controllers are divided in two basic types: analog-servo and digital servo controllers. PI offers the largest selection of both digital and analog piezo motion controllers, drivers and high-voltage amplifiers for piezoelectric mechanisms worldwide. Digital servo controllers (not to be confused with digital interfacing) provide higher linearity, stability and dynamic performance compared to analog servo controllers; they are also easy to tune and optimize by software commands.
What Type of Piezo Mechanisms
The piezo controllers and drivers shown in this overview are designed to drive traditional piezo actuators or piezo flexure nanopositioning mechanisms in single axis or multi-axis configuration – providing typical motion ranges of a few microns to 1mm. (Piezo-motor controllers for longer travel ultrasonic motors, stick-slip motors, and PiezoWalk motors are shown here)
Open & Closed Loop Operation – How do they work
In these precision piezo flexure mechanisms, motion is proportional to the applied voltage at the piezo element (see piezo motion tutorial for details). Typically a position sensor (capacitive, piezoresistive, strain gauge or optical) integrated in the mechanism (or external) is used to provide position feedback to the servo controller to close the loop.
Open loop operation is also possible - in this case the position is roughly proportional to the driver voltage. This may be used in applications, where the exact position does not matter, because feedback is provided by another external signal such as an optical power meter, a quad cell, a force sensor, camera, etc.
Overview of our offering: Digital and analog servo designs; digital and analog interfaces; 60 to- 1100V amplifiers; 1W to 6kW peak power; modular, OEM and PC-plug-in designs; ultra-low-noise, high-stability closed-loop controllers; voltage and charge amplifiers; linear and switched amplifiers; energy-recovery designs. OEM cards, rack-mount solutions and custom controllers with 40 channels and more are available on request.
