THORLABS AMP002 User manual

AMP002
Brand
THORLABS
Model
AMP002
Type
User manual

Below you will find brief information for AMP002. This pre-amplification circuitry amplifies resistance changes within a full Wheatstone bridge strain gauge, producing a signal for monitoring. It uses a low-power instrumentation amplifier with high accuracy, suitable for strain gauge bridge amplification. Current-feedback input provides wide bandwidth of 200kHz at G = 100. A single external resistor sets gain from 1 to 10,000. The Thorlabs strain gauge reader expects a voltage range of >0v to 2V Pk-Pk. It's designed for positive strain and doesn't monitor phase for bridge polarity.

Below you will find brief information for AMP002. This pre-amplification circuitry amplifies resistance changes within a full Wheatstone bridge strain gauge, producing a signal for monitoring. It uses a low-power instrumentation amplifier with high accuracy, suitable for strain gauge bridge amplification. Current-feedback input provides wide bandwidth of 200kHz at G = 100. A single external resistor sets gain from 1 to 10,000. The Thorlabs strain gauge reader expects a voltage range of >0v to 2V Pk-Pk. It's designed for positive strain and doesn't monitor phase for bridge polarity.

HA0172T
AMP002
Strain Gauge Pre Amp
Original Instructions
Page 0 17430-D01
AMP002 Strain Gauge Pre-Amp
Contents
Chaper 1 Overview ................................................................................................................................. 1
Chaper 2 Safety ...................................................................................................................................... 2
2.1 Safety Information ............................................................................................................. 2
2.2 Adjustments ...................................................................................................................... 3
2.3 D-Type Connections ........................................................................................................ 3
2.4 Strain Gauge Bridge Connections ................................................................................... 4
Chaper 3 Thorlabs Worldwide Contacts .............................................................................................. 5
Rev E Aug 2022 Page 1
Chapter 1 Overview
Chapter 1 Overview
This pre-amplification circuitry is designed to amplify resistance changes within a full Wheatstone bridge strain gauge, to produce
a signal suitable for monitoring and interpretation by the Thorlabs strain gauge reader or other piezo electronics with feedback.
This circuit can also be used in other custom applications.
The amplification circuitry uses a low power, general purpose instrumentation amplifier offering excellent accuracy suitable for
strain gauge bridge amplification. Current-feedback input circuitry provides wide bandwidth even at high gain (200kHz at G = 100).
A single external resistor sets any gain from 1 to 10,000. The INA128 amplifier component provides an industry standard gain
equation.
Under normal operating conditions the Thorlabs strain gauge reader anticipates a voltage range of >0v to 2V Pk-Pk for minimum
and maximum strain.
Note: There is no phase monitoring to determine bridge polarity. The bridge should only be used for positive strain, where the
bridge does not cross the balance point during operation.
Page 2 17430-D01
AMP002 Strain Gauge Pre-Amp
Chapter 2 Safety
2.1 Safety Information
For the continuing safety of the operators of this equipment, and the protection of the equipment itself, the operator should
take note of the Warnings, Cautions and Notes throughout this handbook and, where visible, on the product itself.
The following safety symbols may be used throughout the handbook and on the equipment itself.
The following safety symbols may be used throughout the handbook and on the equipment itself.
Warning: Risk of Electrical Shock
Given when there is a risk of injury from electrical shock.
Warning
Given when there is a risk of injury to users.
Caution
Given when there is a risk of damage to the product.
Note
Clarification of an instruction or additional information.
Rev E Aug 2022 Page 3
Chapter 2 Safety
1.2 Adjustments
1) To obtain the required voltage range the offset (VR2) and gain (VR1) potentiometers may need to be adjusted.
See the circuit diagram opposite.
2) For some applications the default gain range may need changing beyond the limit of the adjustable gain. In this instance the
value of R3 may need to be changed. The following equation can be used to help determine what gain resistance is needed.
1.3 D-Type Connections
Pin1: Oscillator Input
Pin2: +15v Input Supply
Pin3: -15v Input Supply
Pin4: 0v Supply
Pin5: Amplifier Output
Pin6: 0v Supply
Pin7: ID Resistor Connection
Pin8: N/C
Pin9: N/C
Note
In order to avoid saturating the Thorlabs strain gauge reader (or other piezo electronics feedback), under full strain conditions
the output should not exceed 2V Pk-Pk.
Note
The pin out of the D-Type connector is such that the amplifier can be connected directly to the Thorlabs range of closed loop
controllers. If used with the BPC301 or BPC302 seriescontrollers, the output is limited to 75 V. If the full 150 V drive is required
the BPC303 controller or KPZ101 Piezo K-Cube together with the K-Cube strain gauge reader (KSG101) should be used.
These controllers provide all the circuitry to convert the output of the preamplifier to a measure of displacement, allowing
accurate position monitoring. In addition, the preamplifier can also be incorporated into other equipment.
G = 1 + 50kΩ
RG
Where:
RG = VR1 x R3
VR1 + R3
12345
6789
Page 4 17430-D01
AMP002 Strain Gauge Pre-Amp
Fig. 1.1 AMP002 Circuit Diagram
1.4 Strain Gauge Bridge Connections
The Thorlabs piezo actuator with feedback (PZS001) is fitted with a full Wheatstone bridge strain gauge that can be monitored by
this circuitry.
See Fig. 1.2 for connection details, where necessary:
Fig. 1.2 Bridge Connections
Caution
When used with the BPC series controllers, connections to the bridge amplifier circuit are as detailed in Fig. 1.1 above.
When used with the KSG101 K-Cube Reader, the TP2 and TP3 connections must be swapped as follows:
TP1 (Red) Oscillator output to strain gauge bridge
TP2 (Blue) Positive input for differential amplifier
TP3 (Yellow) Negative input for differential amplifier
TP4 (Black) Ground
Caution
For correct operation, the value of the ID resistor (R6) must be chosen to match the travel of the piezo stack being driven
- see Table 1 in Fig. 1.1 above.
Use a standard 1% 0.25W resistor.
0VA
0VA
+15V
0VA
0VA
-15V
0VA
0VA
0VA
0VA
0VA
0VA
0VA
+15V
-15V
+15V
-15V
+15V
-15V
0VA
0VA
0VA
0VA
ID RESISTOR
BLACK
GAIN
RED
TP1
OSC
REF
V-
V+
_
+
U1
INA128UA
6
2
3
1
8
5
7
4
C6
10uF
25V X5R
C3
100n
R6
Refer to Table 1
-
+
U2A
TLE2072
2
3
1
4
8
C9
22pF
YELLOW
TP2
IN-
GREEN
TP7
MON
R8 3K3
D9M
J1
1
2
3
4
5
6
7
8
9
OFFSET
VR2
10K
VR1
1K
C7
22pF
TP6
ID_RES2
C1 10uF
25V X5R
C2 10uF
25V X5R
TP8
GND
R2
47R
R3
270R
BLUE
TP3
IN+
C8
220pF
TP5
ID_RES1
-
+
U2B
TLE2072
6
5
7
R10
1K
BLACK
TP4
GND R7 10K
R5
47R
R1
47R
R4
10K
C4
100n
0VA 0VA 0VA 0VA
O3
MOUNTING HOLE
1
O2
MOUNTING HOLE
1
O1
MOUNTING HOLE
1
O4
MOUNTING HOLE
1
R9 1K
C5
10uF
25V X5R
Table 1 - ID Resistor Values
for Thorlabs Piezo Stacks
Value ±1% Max Displacement
0 20μm
1.1k 10μm
2.0k 30μm
3.0k 40μm
4.3k 50μm
6.2k 60μm
8.2k 200μm
10k 80μm
13k 15μm
18k 100μm
Vo
R4
R2 (dummy) R1 (active)
R3
(dummy)
VEX
Bridge Excitation Voltage
Blue (+ve)
Yellow (-ve)
Red (+ve) Black (-ve)
(active)
V0 = Output voltage of full bridge
VEX = Excitation voltage
Rev E Aug 2022 Page 5
Chapter 2 Thorlabs Worldwide Contacts
Chapter 2 Thorlabs Worldwide Contacts
For technical support or sales inquiries, please visit us at www.thorlabs.com/contact for our most up-to-date contact
information.
Thorlabs verifies our compliance with the WEEE (Waste Electrical and Electronic Equipment) directive of the European Community
and the corresponding national laws. Accordingly, all end users in the EC may return "end of life" Annex I category electrical and
electronic equipment sold after August 13, 2005 to Thorlabs, without incurring disposal charges. Eligible units are marked with the
crossed out "wheelie bin" logo (see right), were sold to and are currently owned by a company or institute within the EC, and are not
dissembled or contaminated. Contact Thorlabs for more information. Waste treatment is your own responsibility. "End of life" units
must be returned to Thorlabs or handed to a company specializing in waste recovery. Do not dispose of the unit in a litter bin or at
a public waste disposal site.
USA, Canada, and South America
Thorlabs, Inc.
[email protected]
[email protected]
Europe
Thorlabs GmbH
[email protected]
France
Thorlabs SAS
[email protected]
Japan
[email protected]
UK and Ireland
[email protected]
[email protected]
Scandinavia
[email protected]
Brazil
[email protected]
China
Thorlabs China
[email protected]
www.thorlabs.com
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THORLABS AMP002 User manual

AMP002
Brand
THORLABS
Model
AMP002
Type
User manual

Below you will find brief information for AMP002. This pre-amplification circuitry amplifies resistance changes within a full Wheatstone bridge strain gauge, producing a signal for monitoring. It uses a low-power instrumentation amplifier with high accuracy, suitable for strain gauge bridge amplification. Current-feedback input provides wide bandwidth of 200kHz at G = 100. A single external resistor sets gain from 1 to 10,000. The Thorlabs strain gauge reader expects a voltage range of >0v to 2V Pk-Pk. It's designed for positive strain and doesn't monitor phase for bridge polarity.

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