EB-RMS Datasheet, PDF (1/2 Pages) Murata Manufacturing Co., Ltd. – AC-to-RMS Converter Application Board for DMS-30PC/LCD Meters

DMS-EB-RMS
AC-to-RMS Converter Application Board for DMS-30PC/LCD Meters
FEATURES
Displays true rms values of ac inputs
±0.5% accuracy for DMS-30PC-0 or DMS-
30LCD-0-5
±2% accuracy for DMS-30PC-1 or DMS-
30LCD-1-5
Also works with DMS-40PC/LCD meters (see Ap
Note 11)
PRODUCT OVERVIEW
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 electri-
cally 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-EB-
RMS board should only be installed and serviced by technically qualified personnel. See DMS
Application Note 11 for more details.
(–) INPUT LO 12
(+) INPUT HI 11
10
9
SG4
REF. OUT 8
REF. IN 7
Ḥ
For full details go to
www.murata-ps.com/rohs
C1 100μF
+
5
CAV
4
–VS
6 _OUT
7
U1
+VS
3
CF
2
VIN
8 _COM
1
CC
5
VOUT
4
CAP–
6
LV
GND ³
U2
7
2
OSC
CAP+
8
V+
1
BOOST
C5
+ ^2.2μF
1 +5V SUPPLY
2
J1
+
C2
10μF
C4
2.2μF
+
R1
988k
R2
988k
JP1
R3
1.98k
SG1
SG2
SG3
3 5V RETURN
4 DP3
5 DP2
6 DP1
TB1
1
AC HI
3
AC LOW
J4
J5
U3
1 VIN
3
VOUT
GND 2
2
PS1
4
+V
+VIN
DC/DC
3
–V
–VOUT
1
J6
5
6
+5V
5V Return
Note: Components are user-supplied
and not part of the standard product.
Figure 1. DMS-EB-RMS Schematic Diagram
www.murata-ps.com
Technical enquiries email: [e-mail], tel: [phone]
MPM_DMS-EB-RMS.B01 Page 1 of 2