DMS-EB-RMS Datasheet, PDF (1/1 Pages) List of Unclassifed Manufacturers – AC-to-RMS Converter Application Board for DMS-30PC/LCD Meters

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DMS-EB-RMS
AC-to-RMS Converter
Application Board for
DMS-30PC/LCD Meters
Features
Technical Notes
• 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)
Functional Specifications
(TA = +25°C, VCC = +5V)
Vac Measurement Range:
±200mV meters 0 to 199.9Vac
±2V meters
0 to 750Vac
Conversion Accuracy:
0-200Vac
±0.5%
0-750Vac
±2%
Crest Factors
3, maximum
Input Frequency Range
40Hz to 2kHz
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
DMS-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.
J1
R3
12
11
U1
10
9
C1
8
7
SG 4
C2
JP 1
1
C4
1
R 2 J2
R 1 J3
U3
J4
TB1
PS1
J6
1
2
J5
C5
23 456
U2
SG 3
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
(–) INPUT LO 12
(+) INPUT HI 11
10
9
REF. OUT 8
REF. IN 7
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
3
GND
U2
7
2
OSC
CAP+
8
V+
1
BOOST
C5
+ ^2.2µF
1 +5V SUPPLY
2
J1
+
C2
10µF
C4
2.2µF
+
SG4
R1
988k
R2
988k
R3
1.98k
JP1
SG1
SG2
SG3
3 5V RETURN
4 DP3
5 DP2
6 DP1
J4
J5
Ordering Information
DMS-EB-RMS
DMS-BZL1
DMS-BZL2
AC-to-RMS conversion
board
Bezel assembly
Bezel assembly with
sealing gasket
TB1
1
AC HI
3
AC LOW
U3Q
1 VIN
3
VOUT
GND 2
2
PS1Q
4
+V
+VIN
DC/DC
3
–V
–VOUT
1
J6
5
6
+5V
5V Return
Q Components are user-supplied
and not part of the standard product.
Figure 1. DMS-EB-RMS Schematic Diagram
DS-0398A 1/98
DATEL, Inc., Mansfield, MA 02048 (USA) • Tel: [phone] Fax: [phone] • Email: [e-mail] • 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. Specifications are subject to change without notice. The DATEL logo is a registered DATEL, Inc. trademark.