LVM-110 SIGNAL CONDITIONER
With DC Voltage Output
TE CONNECTIVITY SENSORS
/// LIM-420
MANUAL 09290051-000 REV C
07/2016
Page 5
Initial Setup
In order to begin this process, you must first know a few basic characteristics about the LVDT or RVDT you intend to use with
the LVM-110 conditioning board. The information may be obtained from the sensor calibration sheet, catalog literature, or
datasheet. The list below is the minimum information required to perform a successful calibration:
Recommended operating frequency
Sensitivity at that frequency
Primary (input) impedance at that frequency
The ± full scale (inch or degree) you intend to calibrate over
Analog output signal required by your application
6.1. Oscillator Frequency
Once you have established the proper excitation frequency for your transducer, refer to the table below and the DIP switch
locations on the Circuit Top View (in this manual) to set the LVM-110 oscillator frequency:
Oscillator
Frequency
S1-C
S1-D
2.5 KHZ
OFF
OFF
5 KHZ
ON
OFF
8 KHZ
OFF
ON
10 KHZ
ON
ON
(Refer to Circuit Top View in this manual for ON/OFF positions)
6.2. Oscillator Mode
The Oscillator mode setting depends on the number of LVM-
110’s and LVDT/RVDTs in your system. For a single LVDT or RVDT
system, run the LVM-110 in the stand alone (master) mode. For multi sensor systems, it is best to master and slave the LVM-
110 oscillators to prevent beat frequencies and crosstalk between amplifiers and LVDTs. Select one LVM-110 to serve as the
master oscillator, and setup the balance in the slave mode.
Attempting to synchronize two LVM-110 set as masters may damage one or both units.
Connecting Pin-1 (Sync) of the barrier strip, from unit to unit, will complete the sync bus circuit. The power common serves as
the return line. Use the table below to configure your oscillator mode:
S1-B
Mode
OFF
SLAVE
ON
MASTER
6.3. Oscillator Drive Capability
To ensure LVDT/RVDT compatibility with the LVM-110 you must know the transducer current draw. The LVM-110 is designed
with a robust sine wave oscillator; it is rated for a maximum drive current of 20mA RMS with a fixed amplitude of 3 VRMS. To
ensure compatibility, you will need to know the LVDT/RVDT input impedance for the frequency at which you intend to operate
it.
The transducer input impedance must be equal to or greater than 150 Ohms
, which will result in current draw of 20mA
or less. The input impedance information is available on the datasheets for all our LVDTs and RVDTs.
CAUTION
