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22882-D02
Single-Channel Piezo Controller, 75 V to 150 V
Zero Button
– Initiates the zeroing routine - see Section 3.5.2.
Control Potentiometer
– Used to adjust the voltage applied to the piezo actuator/
stack.
Resolution Button
– Toggles the ‘Control’ potentiometer between ‘Coarse’ and
‘Fine’ adjustment and ‘Parked’ mode - see Section 3.5.1.
Max Voltage Button
– Used to adjust the maximum drive voltage output - see
3.5 Button Operation
3.5.1 Resolution Button
The resolution button cycles the behaviour of the Control potentiometer between
‘Coarse’ and ‘Fine’ adjustment, and ‘Parked’ mode.
In ‘Coarse’ mode, one revolution of the pot varies the output by a factor of 10 greater
than in ‘Fine’ mode. In ‘Open loop’ mode, the full voltage range corresponds to about
12 turns of the pot in ‘Coarse’ mode. In ‘Parked’ mode, the ‘Control’ potentiometer is
disabled, and turning it has no effect.
At power up, the resolution defaults to ‘Coarse’.
3.5.2 Zero Button
The position sensor is a strain gauge fitted to the piezo actuator. Due to limitations in
manufacture, the strain gauge may give a small signal when the actuator is at zero
position with zero volts applied. This ‘offset’ signal must be removed before the
position attained by a specific applied voltage and the position attained by a
corresponding specified distance can be rationalized.
Each actuator has a unique offset value. Therefore the offset should be adjusted
whenever an actuator is replaced. Temperature and prolonged use can affect the
performance of the strain gauge and therefore the offset value. It is good practice to
adjust the offset value whenever the unit is powered up.
To adjust the offset zero:
1) Click the ‘Zero’ button. Notice that the ‘Zeroed’ led flashes to indicate that zeroing
is in progress.
Note
The ‘Zero’ and ‘Open/Closed Loop’ buttons perform the same function as their
respective equivalents on the software GUI panel. If a control PC is connected,
pressing these buttons has the same effect as pressing the correspondingGUI
button. Similarly, the ‘Zeroed’ and ‘Closed’ LEDs correspond to the virtual button
lights on the GUI.
The ‘Volts/Microns’ button is similar in function to the ‘Volts’ button on the GUI but it
operates independently. For example, it is possible to display microns on the GUI
but volts on the front panel
