Pacific Laser Equipment 1SA-1000 - Manual (Page 4)

Servo Amplifier 1ch-1000 User manual
1SA-1000
April 28, 2004 Release: 1.21 2003 by Pacific Laser Equipment
PLEquipment, 3941 S. Bristol St. Unit E, # 122, Santa Ana, CA. 92704, ( & Fax: 509-355-5155, Email: [email protected]
Page 4 of 16
Operation
Two operating modes can be selected from a front panel switch.
Voltage Controlled (VC) or Expansion Controlled (EC).
They are also referred as SERVO OFF ( for VC ) or SERVO ON ( for EC ).
In EC mode an analog input signal of +10 V causes the Piezo to expand to its nominal value and
the monitor out should also measure +10V.
Most dynamic applications require the power amplifier to deliver a short peak current higher than
the average value. This equipment is not designed for dynamic operation.
Manual Operation :
In VC mode the HV output can be controlled manually from 0 to -1200 VDC from the front panel
DC- Offset Potentiometer.
Voltage Controlled Operation (VC-Mode)
In Voltage Control (VC) mode the closed loop position control circuit is bypassed and the system
works like an amplifier. In this mode, the HV output is proportional to the Analog in signal input.
The sensor electronics however works independently and outputs the actual piezo position even
in VC mode if a sensor is connected to the unit.
The nominal input voltage range is 0 to +10 V for 0 to -1000 V output voltage range. For some
applications where the full expansion capability of the piezo translators is needed the full output
voltage range of 0 to -1200 V can be used.
The equivalent Analog IN voltage range is then 0 to +12 V.
For bipolar operation set the output with the external DC-Level potentiometer to an appropriate
level (-500 V) and drive the input with +/- 5 V to get full expansion.
Expansion Controlled Operation (EC-Mode)
The 1SA-1000 has position sensor processing electronics on board.
Sensor controlled operation offers drift and hysteresis free positioning, which enables the
expansion controlled ( EC )mode.
In EC mode, the expansion is directly proportional to the control input signal. The operating
voltage for the piezo actuator may change in the range from 0 to -1200 V. If the actual expansion
of the piezo can't match the commanded position defined by the control signal, the red overflow
LED comes on, on the front panel.
Our standard calibration procedure assures that that the PZT reaches its nominal expansion
value when the input control signal is +10 Volt.
Expansion Control (EC) mode supplies the amplifier with the output of the servo-controller and
the piezo position is changed until the final position is reached. In this controlled mode the
position is directly proportional to the input signal while the applied supply voltage is not.