CSI DSM-5 User manual
FEATURES:
• Battery Powered
• Large 5 Digit Sunlight Readable LCD
• 0.00° to 359.99° Range
• ±0.03° Degree Accuracy
• 47 to 440Hz Reference frequency Range
• 20 to 130V Reference Voltage Range
• 11.8V L-L or 90V L-L Stator Inputs
• No Reference or Stator Loading
• Synthesized Reference
APPLICATIONS:
• Synchro Zeroing
• Field Testing
• Troubleshooting
• Synchro System Alignment
HAND-HELD DIGITAL SYNCHRO METER
HIGH ACCURACY 5 DIGIT
DSM-5
DESCRIPTION
The DSM-5 is the industries first 5 digit hand-held digital
synchro meter. This synchro meter allows the user to
conveniently align and checkout synchro systems on the
assembly line or in the field. The meter comes complete with
rugged carrying case, test leads and battery.
The meter is designed to measure and accurately display the
output angle of the most common synchros. The DSM-5
accepts reference inputs of 20-130VRMS at 47-440Hz. Stator
inputs of either 11.8V L-L or 90V L-L are accepted via switch
selection.
A large sunlight readable LCD display is used to read the
synchro angle over a range of 0.00° to 359.99° to an accuracy
of 0.03°. The display features a low battery indicator that
minimizes the possibility of any false readings.
The DSM-5 uses a ratiometric conversion technique and
employs a type II tracking loop with a synthesized reference
that insures high noise immunity and flicker free operation.
High stator input impedances virtually eliminate loading
effects on the synchro system under test.
OPERATING THE DSM-5
When the instrument is received, the battery is not installed.
A 9V alkaline battery is found in a pouch in the carrying case.
Follow the procedure below for installing or replacing the
battery:
1. Place screwdriver blade into slot in the battery cover and
pry open.
2. Remove battery strap and snap on new battery.
3. Place battery into battery compartment.
4. Replace battery cover.
When battery replacement is necessary, replace with either
9V alkaline or 9V lithium battery. The meter will operate for
an average of 20 hours continuous using an alkaline battery
or 40 hours continuous using a lithium battery. When the low
battery indication (flashing colon) appears, there is
approximately 20 minutes of battery life remaining.
CONTROL SCIENCES INCORPORATED • 9509 VASSAR AVENUE • CHATSWORTH, CA 91311 •818-709-5510 •FAX: 818-709-8546
WEB: WWW.CONTROLSCIENCES.COM •EMAIL: INFO@CONTROLSCIENCES.COM
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CONTROL SCIENCES INCORPORATED • 9509 VASSAR AVENUE • CHATSWORTH, CA 91311 •818-709-5510 •FAX: 818-709-8546
WEB: WWW.CONTROLSCIENCES.COM •EMAIL: INFO@CONTROLSCIENCES.COM
SPECIFICATIONS
Reference Input (R1-R2)
Voltage Range 20 to 130VRMS
Frequency Range 47 to 440Hz
Input Impedance 800KΩ
Stator Input (S1-S2-S3) (Consult factory for custom voltages)
Voltage Select Slide Switch
Voltage Input
Lo Range 11.8V L-L ±10%
Hi Range 90.0V L-L ±10%
Impedance 450KΩ L-L
Rotor/Stator Phase Shift ±45° max.
Display
Type 0.4 inch LCD, sunlight readable
Range 0.00 ° to 359.99°
Resolution 0.01°
Accuracy ±0.03°
Lo Battery Indication Flashing colon
Battery
Type 9V alkaline (supplied) or 9V lithium
Operating Life 20 hours (alkaline)
Temperature Range
Operating 0° to +50°C
Storage -40° to +85°C
Humidity 80% RH non-condensing
Physical
Dimensions 6.0” x 3.12” x 0.81”
Weight 8.0 oz
Material ABS plastic
Color Yellow
ACCESSORIES
The DSM-5 comes complete with the following accessories:
(1) Soft carrying case
(2) Test leads
(3) 9V alkaline battery
CALIBRATION
The DSM-5 comes calibrated with a Certificate of
Conformance. It is recommended that the meter calibration
be checked once per year. A Calibration Test Procedure will
be furnished upon request. Meters may be returned to CSI,
postage pre-paid, for calibration and certification at a
nominal charge. The meter contains no user adjustment
controls. If the meter is found to be out of calibration, it
must be returned to CSI, postage pre-paid, for servicing.
WARRANTY
All units warranted against defects in materials and
workmanship for 1 year from date of shipment. Liability is
expressly limited to servicing, adjusting, or replacing any CSI
product returned to our factory with delivery charges
prepaid. In no case shall our liability exceed the original
purchase price.
OPERATING THE DSM-5
To connect the test leads to the DSM-5, insert the appropriate
lead plug into the DSM-5 input jacks as indicated below:
Connect the DSM-5 to a synchro as follows. Connect R1 and
R2 leads to the corresponding rotor terminals R1, R2. Connect
S1, S2 and S3 leads to the corresponding stator terminals S1,
S2 and S3.
To turn on the DSM-5, set slide switch to either HI or LO range
position depending on which stator voltage to be measured.
LO position is used to measure 11.8VL-L voltages, HI position is
used to measure 90VL-L voltages. The meter will not be
damaged by the application of an over-voltage.
The meter does not contain an internal reference excitation
supply, therefore the synchro rotor voltage (R1-R2) must be
supplied from an external excitation source.
THEORY OF OPERATION
The heart of the DSM-5 is a 16 bit synchro to digital converter.
The reference input (R1-R2) and synchro stator (S1-S2-S3)
signals are combined creating a synthesized reference signal
that is in-phase with the stator signals. The synchro stator
signals are converted to sine and cosine voltages via a solid
state Scott-T circuit with high input impedance and is
insensitive to voltage and frequency variations. The sine and
cosine voltages are ratiometrically multiplied producing an
error signal that is demodulated using the synthesized
reference signal, allowing for up to ±45° of rotor to stator
phase shift without any degradation of accuracy. The
demodulated error signal is fed to an analog integrator, VCO
and 16 bit binary up/down counter that is fed back to the
sine/cosine multipliers creating a type II servo loop. The 16
bit binary angle is converted to a 5 decade BCD angle and
displayed on a 5 digit LCD display.
10/14 REV A
TEST LEAD
DSM-5
INPUT JACK
MARKING COLOR MARKING
R1 RED R1 (H)
R2 BLACK R2 (C)
S1 BLUE S1 (X)
S2 BLACK S2 (Z)
S3 YELLOW S3 (Y)
