C&D Technologies DATEL DMS-EB2 User manual

MPM_DMS-EB2_D00 Page 1 of 4
DIGITAL PANEL METERS
DMS-EB2
Multi-Purpose Application Board
for DMS-20PC/LCD Meters
The DMS-EB2 Application Board was designed for quick and easy application/evalu-
ation of DATEL's subminiature DMS-20PC/LCD Series, 3½ Digit, LED/LCD Display, Digital
Panel Voltmeters. The DMS-EB2's versatility, low cost and direct DMS-20PC/LCD plug-in
compatibility makes interfacing a breeze. The DMS-EB2 covers many common panel-
meter applications while providing easy signal and power I/O terminations (via a standard
MOLEX connector) and plug-in versatility when changing from one application to another.
The DMS-EB2 has provisions for such common applications as input dividers for high
input voltages, gain (span) adjustment, 9/12Vdc battery operation, and decimal point place-
ment. The board permits direct signal I/O wiring via the interface connector or soldering
directly to the board. The DMS-EB2 is fully compatible with all four versions of the DMS-
20PC/LCD (±200mV, ±2V, ±20V, ±200V) making it interchangeable from meter to meter
and application to application. Solder gaps
are conveniently placed on the board and
may be quickly bridged or cut as required.
This low-cost addition to DATEL's
expanding line of subminiature meters dem-
onstrates our continuing commitment to offer
the most versatile, easy-to-use panel-meter
products.
FEATURES
■ Gain (span) adjustment
■ Input divider network for attenuating voltages
up to 250Vdc
■ Operate meter and board from +5V supply or
9/12V battery
■ On-board solder gaps for decimal point placement
■ On-board I/O connector for easy power and signal input
Figure 1. DMS-EB2 Schematic Diagram
U1
+VIN
+VOUT
1 2 3 4 5 6
SG15
(–) INPUT LO
(+) INPUT HI
ANALOG�
COMMON�
TEST/HOLD
�
REF. OUT
REF. IN
12
11
8
7
10
9
SG3
SG2
SG1
DP 3
DP 2
DP 1
+5V SUPPLY/�
+BATTERY
�
3
4
5
6
2
1
5V RETURN/�
–BATTERY
�
DISPLAY�
ENABLE
�
LM7805CT
+
C2
10µF
35V
GND
SG5
C1
1.5µF, 50V
SG14 SG10
R2
R1
R3
+5V SUPPLY/�
+BATTERY
(Close for�
Offset Adjust)
SG6
SG4
(+) (–)
+V
GND
HI LO
TST/�
HOLD�
IN
TST/�
HOLD�
OUT
–V
Components are user-supplied �
and not part of the standard product
SG7-SG9 and SG11-SG13 are not used.
J1
J2
Closed solder gap
Open solder gap








R1
R2
R5 U1
SG15
SG14 SG6 SG5
J1
SG4
SG3
SG1
SG2
C1 +C2
1
SG10
12
1 2 3 4 5 6
J2
For updated, full-size data sheets visit: www.cd4power.com
For full details go to
www.cd4power.com/rohs

MULTI-PURPOSE APPLICATION BOARDS FOR DMS-20METERS
DMS-EB2
MPM_DMS-EB2_D00 Page 2 of 4
DIGITAL PANEL METERS
www.cd4power.com
TECHNICAL NOTES
APPLICATIONS
1. LCD Backlighting: To backlight a DMS-20LCD meter, connect J1, pin
3 (TEST/HOLD IN) to J1, pin 6 (GND). This allows for external control,
via a switch, of the backlight feature. The switch should be rated for low
voltage operation at 35mA.
2. 9V LCD Meters: DMS-20LCD-X-9 meters cannot be used in a single-
ended configuration, i.e., with (–) IN LO tied to GND. On these models,
both (–) IN LO and (+) IN HI have to be a minimum of 1.5V above and
1.5V below J1 pins 6 and 5, respectively. To operate from a 9V or 12V
battery with (–) IN LO tied to GND, use a 5V-powered meter (DMS-
20LCD-X-5), install U1 (LM7805CT) and open SG4.
3. Input Resistor Dividers: Always use 1%, or better, metal-film resistors
for R1 and R2, and also make sure their power and voltage ratings are
adequate for the given application.
4. Using U1 (LM7805CT): The input power range specified in the Battery
Operation section is rated conservatively assuming a 100mA LED meter
or a 35mA backlit LCD meter. If a non-backlit LCD model or the low-
power LED model is used, the input voltage range can be extended up to
32Vdc.
As shipped, the DMS-EB2 is configured for single-ended operation. This
configuration is preferred for simple voltage measurements and will gen-
erally cover most standard applications. Figure 1 indicates which solder
gaps are shipped closed from the factory.
Simply solder the board onto the meter (pin 1 to pin 1), connect the power
supply to J1, pin 5 (+V) and the power return to J1, pin 6 (GROUND).
1. Decimal Point Placement: DATEL ships the DMS-EB2 with all decimal
point solder gaps (SG1, SG2 and SG3) open. To enable a specific deci-
mal point, close its respective solder gap with solder. When re-assigning
decimal places for subsequent applications, remember to unsolder previ-
ously closed solder gaps.
Close SG1 for 1.999 (DP1)
Close SG2 for 19.99 (DP2)
Close SG3 for 199.9 (DP3)
2. Display Test (Not Available on LCD Models): Tie pin 4 (TEST/HOLD
OUT) to pin 3 (TEST/HOLD IN) to test the display of the DMS-20PC. Do
not leave the meter in the test mode for more than 10 seconds. On LED
meters with the HOLD option, tying pins 3 and 4 together freezes the
display reading.
3. Battery Operation: Open SG4 and install U1 (LM7805CT) with its metal
tab facing to the left as shown in Figure 3. Allowable input power ranges
(J1, pins 5 and 6) are as follows:
DMS-20PC-X-XS +7.5 to +12.6Vdc
DMS-20PC-X-XL +7.5 to +32Vdc
C2 (10µF/35V) can be added to reduce noise. Observe correct polarity.
Refer to Technical Note 4 for more information.
Figure 2. J1 Connector Pinout
Pin Function
1 (+) INPUT HI
2 (–) INPUT LO
3 TEST/HOLD IN
4 TEST/HOLD OUT
5 +V (Positive power connection)
6 –V (Ground, negative power return)
1 2 3 4 5 6
� �
+V
HI�
(+)
LO�
(–)
TST/�
HOLD�
IN
TST/�
HOLD�
OUT
–V�
GND
J1
DMS-EB2 Application board with mating connector and terminals
DMS-BZL3 DMS-20 bezel assembly
DMS-BZL4 DMS-20 bezel assembly with sealing gasket
39-0304000 LM7805CT (U1), +5V-output, three-terminal regulator
39-2359625 6-position pc-board socket
Input Supply Range
See applicable meter's data sheet
Input Supply Range U1 (LM7805CT) Installed:
DMS-20PC-X-XS +7.5 to +12.6V
DMS-20PC-X-XL +7.5 to +32.0V
DMS-20LCD-X-5 +7.5 to +32.0V
DMS-20LCD-X-5B +7.5 to +12.6V
Operating and Storage Temperature
See applicable meter's data sheet
Humidity 0 to 95%, non-condensing
Dimensions 1.25" (31.8mm)L x 0.75" (19.1mm)H
J1 Connector & Wire Information
Terminal Type DATEL P/N 39-2099090
Crimp Tool DATEL P/N 39-2099000
Wire Size 22 to 26 AWG
Insulation Diameter 0.062" (1.57mm) max.
Stripping Length 0.100" to 0.125"
(2.54 to 3.17mm)
Ordering Information
Functional Specifications (TA = 25ºC) A 10µF/35V tantalum capacitor (C2 on schematic) should be installed
with the polarized end next to the + symbol on the DMS-EB2. This is
especially important if the power source is located far from U1.
5. Soldering: DATEL recommends the use of "no-clean" solders when
making modifications to the DMS-EB2.

MULTI-PURPOSE APPLICATION BOARDS FOR DMS-20METERS
DMS-EB2
MPM_DMS-EB2_D00 Page 3 of 4
DIGITAL PANEL METERS
www.cd4power.com
Figure 3. Installing U1
Figure 4. Installing R1
SG10
12
R3
R1
To measure input voltages
greater than ±100Vdc,
these two etch paths.
open SG10 and also cut
SG1
SG2 SG3
1
U1
TO-3-style tab
points to left
4. Calibration Adjustment: The DMS-EB2 has provisions for adjusting the
calibration of the DMS-20 meter. Calibration adjustment is useful when
an input divider (using R1 and R2) is necessary to scale the input voltage.
The calibration potentiometer allows "tweaking" of the display reading.
Using the calibration potentiometer
Adjust the calibration pot on the back of the meter as desired. The
adjustment range is only 3/4 of a turn. Do not force the pot past its end
stops.
5. Differential Input Signals (Signal Referenced to Power Source): Open
SG5. Apply the input signal to pin 1, (+) IN HI, and pin 2, (–) IN LO, of J1.
NOTE: Common mode voltage must not exceed ±2Vdc.
6. Measuring Input Voltages Greater than 1.999Vdc (Use DMS-20PC/
LCD-1 Only):
CAUTION: Do not exceed 250Vdc input signal.
1. Open SG10. For applications in which input voltages exceed ±100Vdc,
also cut the 2 adjoining traces.
2. Calculate values for R1 and R2 as follows:
R2 = (FSI x R1) / ( |VIN| - FSI)
Where:
FSI = The attenuated voltage, between the meter's (–) IN LO and (+) IN
HI pins, needed to achieve the desired display readings
VIN = Input voltage at J1 (beween pins 1 and 2)
A typical value for R1 is 1MΩ. The sum of R1 + R2 should be
between 50kΩ and 10MΩ.
3. Enable DP3 by soldering SG3.
4. Calibrate the meter using a known voltage source. Adjust the internal
gain potentiometer to compensate for variations in R1 and R2.
Example
VIN is 199.9Vdc, and the display reading must be "199.9".
1. Assume R1 = 1.0MΩ.
2. R2 = (FSI x R1) / ( |VIN| - FSI)
R2 = (1.999 x 1,000,000) / (199.9 - 1.999)
R2 = 10101.01Ω or 10kΩ
7. Current Measurements (Use 200mV Model, DMS-20PC/LCD-0): The
following instructions are for measuring current derived from the DMS-
20PC/LCD's power source. When measuring current that is floating with
respect to J1, pin 6 (GROUND), leave SG5 closed.
CAUTION: Do not exceed 1 Ampere input current.
1. Install R2 (R2 = FSR / (IMAX x 10000)) where FSR is the
desired reading (0-1999) and IMAX is between 0 -1 Ampere.
2. Open SG5.
3. Apply input signal (current) to (+)IN HI and (–) IN LO.
4. Adjust internal gain pot for desired full scale readings.
5. Enable decimal points using either SG1, SG2 or SG3.
Example
A 1.0 Ampere input must read "1.000" on the display.
R2 = 1000 / (1 x 10000)
R2 = 0.1 Ohm
Enable DP1 via SG1 for reading of 1.000
8. Displaying DMS-20PC/LCD's Power Source
(Use DMS-20PC/LCD-2, 5V-Powered Models Only):
1. If the power source is higher than 5Vdc, be sure to install U1 and cut
SG4. See Battery Operation section and Technical Note 4.
2. Solder a short piece of jumper wire across the two holes labeled J2.
3. Close SG2 to enable DP2.

MULTI-PURPOSE APPLICATION BOARDS FOR DMS-20METERS
DMS-EB2
DS-0340D 05/2007
© 2006 C&D Technologies, Inc.
C&D Technologies, Inc. makes no representation that the use of its products in the circuits described herein, or the use of other technical
information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein do not imply the
granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without
notice. The DATEL logo is a registered C&D Technologies, Inc. trademark.
C&D Technologies, Inc.
11 Cabot Boulevard, Mansfield, MA 02048-1151 U.S.A.
Tel: [phone] [phone] Fax: [phone]
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MPM_DMS-EB2_D00 Page 4 of 4
DIGITAL PANEL METERS
For updated, full-size data sheets visit: www.cd4power.com