DMS-EB-RMS - Murata Power Solutions

DMS-EB-RMS
AC-to-RMS Converter Application Board for DMS-30PC/LCD Meters
PRODUCT OVERVIEW
FEATURES
Displays true rms values of ac inputs
±0.5% accuracy for DMS-30PC-0 or DMS30LCD-0-5
±2% accuracy for DMS-30PC-1 or DMS30LCD-1-5
Also works with DMS-40PC/LCD meters (see Ap
Note 11)
Description: The DMS-EB-RMS board allows the true rms value of ac signals to be displayed on
5V-powered DMS-30PC/LCD digital voltmeters. The meter/board combination has an input range of
0-750Vac with ±2V meters (1Vac resolution) or 0-199.9Vac with ±200mV meters (0.1Vac resolution).
A built-in screw-terminal block reliably interfaces signal and power connections. The DMS-EB-RMS
now accommodates user-installed modifications such as input-scaling resistors and isolated +5V dc/dc
converters.
Power and Safety Precautions: The DMS-EB-RMS’s AC HI and AC LOW inputs are not electrically isolated from its 5V supply (AC LOW is connected directly to 5V RETURN). When measuring any
input signal which is derived from ac power mains, a dedicated (i.e., it only powers the DMS-EB-RMS),
transformer-isolated +5V supply, with a minimum 1kV breakdown rating, must be used to power the
DMS-EB-RMS board/meter combination. When measuring ac power mains inputs, never connect the
DMS-EB-RMS’s 5V RETURN to chassis/earth ground anywhere in the system. Failing to follow these
instructions could defeat any safety grounding and will place the system +5V power supply, and all its
associated circuitry, at dangerously elevated ac-line potentials. In many applications, the MS-EB-RMS
installation is required to meet electrical code requirements. To ensure safe operation, the DMS-EBRMS board should only be installed and serviced by technically qualified personnel. See DMS
Application Note 11 for more details.
C1 100μF
+
5
6
(–) INPUT LO 12
7
8
(+) INPUT HI 11
CAV
–VS
OUT
CF
U1
+VS
VIN
COM
CC
10
J1
4
5
3
6
2
7
1
8
C4
2.2μF
+
CAP–
VOUT
LV
GND
U2
CAP+
OSC
V+
BOOST
4
C5
2.2μF
3
+
2
1
2
3 5V RETURN
+
SG1
4 DP3
C2
10μF
9
SG2
SG4
REF. OUT 8
REF. IN
1 +5V SUPPLY
R1
988k
5 DP2
R2
988k
R3
1.98k
SG3
6 DP1
7
JP1
J4
J5
U3
3
1 VIN
PS1
2
+V
VOUT
4
+VIN
DC/DC
GND 2
1
–V
–VOUT
3
J6
TB1
1
AC HI
3
AC LOW
5
+5V
6
5V Return
Note: Components are user-supplied
and not part of the standard product.
Figure 1. DMS-EB-RMS Schematic Diagram
For full details go to
www.murata-ps.com/rohs
www.murata-ps.com
Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000
MPM_DMS-EB-RMS.B01 Page 1 of 2
DMS-EB-RMS
AC-to-RMS Converter Application Board for DMS-30PC/LCD Meters
Ordering Information
DMS-EB-RMS-C AC-to-RMS conversion board
DMS-BZL1-C
Bezel assembly
DMS-BZL2-C
Bezel assembly with sealing gasket
Functional Specifications
(TA = +25°C, VCC = +5V)
Vac Measurement Range:
±200mV meters
±2V meters
0 to 199.9Vac
0 to 750Vac
Conversion Accuracy:
0-200Vac
0-750Vac
±0.5%
±2%
Figure 2. DMS-EB-RMS Board
Crest Factors
3, maximum
Input Frequency Range
40Hz to 2kHz
Primary Operating Power
+5V (±5%)
Current Consumption (Board only)
+0.5mA typ., +1mA max.
Operating Temperature Range
0 to +60°C
Storage Temperature Range
–20 to +75°C
Humidity
0 to 95%, non-condensing
Dimensions
2.02" (51.31mm)W x 0.83" (21.08mm)H
USA:
Murata Power Solutions, Inc.
11 Cabot Boulevard, Mansfield, MA 02048-1151 U.S.A.
Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356
www.murata-ps.com email: sales@murata-ps.com ISO 9001 and 14001 REGISTERED
12/15/08
Murata Power Solutions, 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.
© 2008 Murata Power Solutions, Inc.
www.murata-ps.com
Mansfield (MA), Tel: (508) 339-3000, email: sales@murata-ps.com
Canada:
Toronto, Tel: (866) 740-1232, email: toronto@murata-ps.com
UK:
Milton Keynes, Tel: +44 (0)1908 615232, email: mk@murata-ps.com
France:
Montigny Le Bretonneux, Tel: +33 (0)1 34 60 01 01, email: france@murata-ps.com
Germany:
München, Tel: +49 (0)89-544334-0, email: munich@murata-ps.com
Japan:
Tokyo, Tel: 3-3779-1031, email: sales_tokyo@murata-ps.com
Osaka, Tel: 6-6354-2025, email: sales_osaka@murata-ps.com
China:
Shanghai, Tel: +86 215 027 3678, email: shanghai@murata-ps.com
Guangzhou, Tel: +86 208 221 8066, email: guangzhou@murata-ps.com
Singapore:
Parkway Centre, Tel: +65 6348 9096, email: singapore@murata-ps.com
Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000
MPM_DMS-EB-RMS.B01 Page 2 of 2