DATEL, Inc., Manseld, MA 02048 (USA) • Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356 • Email: sales@datel.com • Internet: www.datel.com
DATEL 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. Specications are subject to change without notice. The DATEL logo is a registered DATEL, Inc. trademark.
® ®
SG13
(–) INPUT LO
(+) INPUT HI
ANALOG
COMMON
+1.23V
REF. OUT
REF. OUT
REF. IN
12
11
8
7
10
9
R3
10.5k
R4
2k SG7
SG11
R1
R2
SG10
SG14
SG9
SG8
SG12
R5
50k
SG6 SG4
SG5
C3
22µF
10V
C4
0.1µF
50V
+
C2
0.22µF
50V
LM7805CT
R6
4.7k
SG3
SG2
SG1
DP 3
DP 2
DP 1
+5V SUPPLY/
+BATTERY
3
4
5
6
2
1
5V RETURN/
–BATTERY
TEST/
BACKLIGHT
(+) (–) IN OUT
+V
GND
HI LO TST TST –V
Components are user-supplied
and not part of the standard product
Components are part of the resistor accessory
kit RN-DMS (see Ordering Information).
J1
Closed solder gap
Open solder gap
U2
U1
+VIN
-VIN
+VOUT
-VOUT
+VIN
+VOUT
1 2 3 4 5 6
DMS-EB-DC/DC
DC/DC Converter
and Isolation Board for
DMS-30PC/LCD Meters
Features
DS-0396C 04/02
Actual Size
• Provide isolated +5V power for
DMS-30 Series meters
• 750V minimum isolation
• Ideal for high-side dc ammeters shunts
• Provisions for +12V operation
• Includes all the features of the standard
DMS-EB board
• Use with: All DMS-30PC
DMS-30LCD (5V models only)
Ordering Information
DMS-EB-DC/DC DC/DC converter board
(with mating connector)
DMS-BZL1 Bezel assembly
DMS-BZL2 Bezel assembly with sealing gasket
RN-DMS Resistor accessory kit
Input Voltage +5V (±5%)
Input Current:
Typical +150mA
Maximum +250mA
Regulator Input Voltage Range (LM7805CT):
DMS-30PC-X-XS +7.5 to +9.5Vdc
DMS-30PC-X-RL +7.5 to +18Vdc
DMS-30LCD-X-5(B) +7.5 to +18Vdc
Output Voltage +5V (±5%)
Isolation 750V, minimum
Operating Temperature 0 to +60°C
Storage Temperature –20 to +75°C
Dimensions:
2.02" (51.31mm)L x 0.83" (21.08mm)W
Humidity (Non-condensing) 0 to 95%
Functional Specications (TA = 25°C, VCC = +5V)
Order online at www.datel.com
Description: The DMS-EB-DC/DC Application Board provides isolated +5V
power for DATEL's DMS-30PC/LCD Series, 3 Digit, LED/LCD Display, Digital
Panel Voltmeters. This add-on board is ideal for applications requiring isolation (up
to 750V) between the input signal and the meter's +5V supply.
Features: The DMS-EB-DC/DC is an excellent choice for dc ammeter applica-
tions. These ammeters typically have the current shunt located on the positive side
of the power supply — a condition which usually exceeds the meter's common
mode voltage limit. Input-to-output isolation is required if the power source being
measured also powers the DMS-30. DATEL's new Panel Meter Catalog has a
detailed application note on dc ammeters.
Applications: The DMS-EB-DC/DC incorporates all standard features of the
DMS-EB board; the only exception being the smaller allowable range of power
supply voltage when using the LM7805 3-terminal regulator. Use the DMS-EB-
DC/DC with any DMS-30PC meter or DMS-30LCD meter (5V-powered models
only).
+7.5-18V Operation (Optional): Open SG4 and install U2 (LM7805CT) with
its metal tab adjacent to U1. Applications requiring a lower dropout voltage should
consider the LM2931T-5. Exceeding the allowable regulator input voltage ranges
(see Functional Specications) will cause device overheating! As is the case
when specifying any electronic power component, be sure to consult all applicable
manufacturer's data sheets.
Figure 1. DMS-EB-DC/DC Schematic Diagram
R3
R1 R2
R5 R4
U2
SG10
SG11 SG9 SG8 SG7
C3
SG14
SG6 SG5
C4
C1
J1
SG4
SG3 SG1
SG2
C4
1
SG12
SG13
12
1 2 3 4 5 6
U1
R6
