Pacific Laser Equipment 1SA-1000 - Manual (Page 12)

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 12 of 16
6. Strain Gage Sensors
Strain Gage Sensors (SGS) for piezo actuator applications use DC signals and consist of
resistive films bonded to the ceramic piezoelectric actuator. The change in length of the piezo
stack changes the resistance of the strain gage. The change is proportional to the change in
displacement of the piezo actuator. Up to 4 strain gages are used in a bridge configuration for
better stability and resolution.
Depending on the PZT model, either all four-bridge quadrants are active (full bridge) or two are
active and the other two consist of fixed resistors (half bridge).
The Wheatstone bridge is balanced if all branches have the same resistance. The bridge
becomes unbalanced if one or more resistances change due to expansion or contraction.
Relative changes in length of 0.1% can be detected. At with 90µm nominal expansion the
resolution is 90nm.
Wiring of SGS:
Name: 1SA-1000UM
Release: 1.21
Release Date: April 28, 2004
© 2001 by
Pacific Laser Equipment