MURATA EB-ACDC

DMS-EB-AC/DC
100-264Vac Power Supply
Accessory Board for DMS-30PC/LCD Panel Meters
FEATURES
Allows meters to operate from 100 to 240Vac
(50/60Hz)
Screw-type terminal block connections
PRODUCT OVERVIEW
Provides 1500V isolation between AC supply
and input signal
This low-cost accessory board provides an easy way of powering all DMS-30PC-X-RL (red low-power
models only), as well as all DMS-30LCD and DMS-40LCD (non-backlit, +5V-powered models only) panel
meters from 100-264Vac (50/60Hz). The on-board AC/DC converter provides an isolated +5Vdc to power
the meter’s electronics, while providing 1500Vac isolation between the AC supply and the input signal
being measured. Line power and input signals connect to two rugged, screw-style terminal blocks (TB1 &
TB2) permanently mounted on the DMS-EB-AC/DC. This type of terminal block provides reliable mechanical connections and eliminates the need for any extra wiring harness connectors.
The DMS-EB-AC/DC board includes provisions for installing several usersupplied components that
are required when the meter must be scaled to display non-standard input ranges. The DMS-EB-AC/DC
has provisions for such common applications as attenuation of high input voltages, gain (span) and offset
(zero) adjustments, and direct decimal point placement. The DMS-EB-AC/DC is compatible with all four
input versions of the DMS-30 Series meters (±200mV, ±2V, ±20V and ±200V). Solder gaps, conveniently
placed on the board, are easily bridged or cut to configure the board to meet each application’s specific
requirements.
Has prototyping features of the standard DMSEB board
On-board solder gaps for decimal point placement
Same size as DMS-30/40 meters 2.02"
(51.3mm)L x 0.82" (20.8mm)W
Low cost
SIMPLIFIED SCHEMATIC
(–) INPUT LO
12
+VIN
SG14
(+) INPUT HI
ANALOG
COMMON
SG10
R2 
11
–VIN
10
R3
10.5k
R4
2k
9
8
2
–VOUT

3
SG7
+
REF. OUT/DP4
SG13
SG8
4
R5 
5V
RETURN
SG3
SG6
SG11
DP 3
SG2
5
50k
SG1
SG4
REF. IN
+5V
SUPPLY
R1
SG9
+1.23V
REF. OUT
1
+VOUT
DC/DC
CONVERTER
6
DP 2
DP 1
7
SG12
~ Refer to Mechanical Layout drawing for components and
solder gap location.
 Components are user-supplied and not part of the
standard product.
€ SG5 is not used
Open solder gap
TB1
TB2
1
HI
(+)
2
LO
(–)
1
AC
LO
Closed solder gap
2
AC
HI
Figure 1. DMS-EB-AC/DC Simplified Schematic Diagram
For full details go to
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Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000
MPM_DMS-EB-AC/DC.B01 Page 1 of 4
DMS-EB-AC/DC
100-264Vac Power Supply
Accessory Board for DMS-30PC/LCD Panel Meters
Ordering Information
DMS-EB-AC/DC-C
AC power supply board
Functional Specifications
(TA = +25°C)
AC Supply Voltage:
100 to 264Vac @ 47-68Hz
AC Supply Current @ 264Vac/60Hz
60mA, maximum
Isolation
1500Vac, minimum
Operating Temperature Range
0 to +60°C
Storage Temperature Range
–25 to +75°C
Humidity
0 to 95%, non-condensing
Dimensions
2.02" (51.31mm)L x 0.82" (20.8mm)W
x 0.60" (15.3mm)D
TB1 and TB2 Wire Size and Strip Length
Wire Size
16 to 22 AWG (solid or stranded)
Strip Length
0.25" (6.35mm)
Screw Torque
3.6 pound-inches (0.4Nm)
Rated Voltage
310Vac
Introduction
As shipped, the DMS-EB-AC/DC is configured for use with +5V-powered DMS-30PC or DMS-30LCD 3½ digit meters using the meter’s internal reference (SG13 is closed). This configuration is the most common
and works well for most simple voltage measurements. Please read all
of the following technical notes and perform any required modifications
before soldering the DMS-EB-AC/DC onto the host meter.
Many of the applications described below apply to both DMS-30
(3½ digit resolution) and DMS-40 (4½ digit resolution) meters. However,
Application 5, installing the span (R4) and offset (R5) adjust potentiometers, can only be used with DMS-30PC/LCD meters. Also note that
some of the other applications require the installation of R4 and R5. See
Technical Note 4 when using the DMS-EB-AC/DC with DMS-40LCD
meters.
!IMPORTANT! AC power must be disconnected from TB2
terminals 1 and 2 before making modifications or installing
user-supplied components on the DMS-EB-AC/DC board! In many
applications, the DMS-EB-AC/DC installation is subject to electrical-code
requirements (for example, the NEC in the USA). Fusing, grounding,
wire gauges, and leakage currents may be regulated items. Since the
DMS-EB-AC/DC is a line-operated device, it presents a shock hazard
and should be installed only by qualified personnel. Do not hesitate to
contact DATEL if you have any questions.
TECHNICAL NOTES
1. Soldering and Wiring: DATEL recommends the use of “no-clean”
solders when installing components or making modifications to the
DMSEB-AC/DC. Before mating the DMS-EB-AC/DC to the host meter,
ensure that modifications, if any, have been correctly made and that
all cut solder-gaps are fully open. Align pin 1 of the meter with pin 1 of
the DMS-EB-AC/DC, slide the board down flush to the meter’s housing
and solder all 12 pins. Lastly, carefully cut the meter’s 12 pins as close
as possible to the pc-board surface.
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Making absolutely sure that the AC supply is de-energized (OFF), connect the AC supply to TB2 terminals 1 (AC LO) and 2 (AC HI). Connect
the input signal being measured to TB1 terminals 1 (+HI) and 2 (-LO).
2. Grounding/Isolation: Because DMS-30 and DMS-40 meters are
housed in a plastic case, a connection to AC earth ground is not
required. When wired per the instructions above, the DMS-EB-AC/DC
board provides a minimum of 1500V isolation between its AC supply
input (TB2) and its input signal (TB1). However, please keep in mind
that in many applications the LO side of the input signal may be connected to AC ground (i.e., earth ground) elsewhere in the system. Any
Issues pertaining to grounding and/or isolation of the DMS-EBAC/DC power supply board must be referred to qualified technical
personnel.
3. Input Resistor Dividers (See Figure 4): Use 1%, or better, metal film
resistors for R1 and R2 in DMS-30 applications, and 0.5%, or better, in
DMS-40LCD applications. Make sure the resistor’s power and voltage
ratings are adequate for the given application. Using tight-tolerance
resistors in input scaling circuits allows most calibration adjustments
to be made with the meter’s internal rear-mounted potentiometers,
through the access holes provided (see Technical Note 5 below).
4. DMS-40LCD Meters: To change the input range on DMS-40LCD
meters from the default low-range (i.e., with pin 2 of the meter open)
to the high range, short pin 2 to pin 1 (+5V) on the top right side of
DMS-EB-AC/DC board (refer to Figure 2 and the DMS-40LCD data
sheet for more information).
5. Calibration Potentiometer Adjustment Holes: Two overlapping
holes on the DMS-EB-AC/DC provide access to the built-in ¾-turn
calibration potentiometer on DMS-30 meters or the 3-turn potentiometer on DMS-40LCD meters. The adjustment range of both pots is very
narrow. See the applicable product data sheet for more information on
each meter’s calibration potentiometers.
6. Solder Gap Identification (See Figure 2): Each solder gap’s respective number is printed directly on the pc-board surface in copper etch.
Be sure to double check all solder gap modifications before applying
ac power and the input signal to the DMS-EB-AC/DC.
7. AC Supply Transients: The DMS-EB-AC/DC can withstand transients
typically found in instrumentation environments. Installations which
contain ac-powered equipment capable of generating large voltage
and/or current surges should use external energy-clamping devices. A
1500 Watt bi-directional transzorb with a minimum stand-off voltage
rating that matches the highest line-voltage peaks will provide additional protection under severe fault conditions. If a transzorb or other
energy limiting device is used, the ac supply feeding the DMS-EB-AC/
DC should have its own fuse. Refer to the fusing section for more
information.
8. AC Supply Fusing: The DMS-EB-AC/DC board does not have an
internal fusing device. If required, a 0.2A slow-acting fuse is recommended. Be sure the fuse is rated for the applied line voltage.
Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000
MPM_DMS-EB-AC/DC.B01 Page 2 of 4
DMS-EB-AC/DC
100-264Vac Power Supply
Accessory Board for DMS-30PC/LCD Panel Meters
SG10
12
1
SG14
SG7
SG8
DP4
SG6
TB2
TB1
SG4
SG13
SG12
SG3 (DP3)
SG11
SG2 (DP2)
R3
SG1 (DP1)
SG9
1
HI(+)
2
1
2
LO(–)
AC LO
AC HI
Figure 2. DMS-EB-AC/DC Board
APPLICATIONS
1. Decimal Point Placement: DATEL ships the DMS-EB-AC/DC with
all decimal point solder gaps (SG1, SG2, SG3 and SG4) open. To
enable a specific decimal point, close its respective solder gap with
solder. When reassigning decimal places for subsequent applications,
remember to open any previously closed solder gaps.
Close SG1 for 1.999 (DP1)
Close SG2 for 19.99 (DP2)
Close SG3 for 199.9 (DP3)
Close SG4 for 1999.9 (DP4 on DMS-40LCD)
2. Span (Gain) and Zero (Offset) Adjustments (See Figure 3): Locations are included on the DMS-EB-AC/DC to add user-supplied potentiometers R4 and R5. Recommended values for these two components
are as follows: R4: 2KΩ, 10-20-turns; R5: 50KΩ, 10-20 turns. Vishay's
T93YA series potentiometers are suitable for this application. Make
sure to use only RoHS-compliant components and solders when making modifications to DMS-EB-AC/DC.
Once installed, these components permit the span and zero adjustments described in the following sections. R4 provides span adjust,
while R5 applies and offset voltage to (-) IN LO (J1, pin 2).
Using Potentiometer R4 for Span Adjustment (DMS-30PC and DMS30LCD Meters Only)
1. For DMS-30-1, -2, and -3 models (+/-2V, +/-20V, +/-200V ranges):
Configuring the DMS-EB-AC/DC for span adjustment is simply a
matter of installing potentiometer R4, opening SG13, and then closing SG8, SG11, and SG12.
2. For DMS-30-0 models (+/-200mV ranges): Span adjustment requires that you open SG8, SG11 (if closed) and SG13 and then close
SG7, SG and SG12. Then install R4.
Adjust span as desired. DMS-30-1, -2, and -3 span adjustment
range is typically +10% and –5%. The DMS-30-0 has a much wider
span adjust, however, it should be limited to ±10% for optimum
accuracy and stability.
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Using Potentiometer R5 to Apply a Positive Offset to Pin 12 (-) IN LO
1. Open SG14 and close SG6.
2. Install 50K potentiometer R5.
Potentiometer R5 applies a stable, positive dc-offset voltage to
the meter’s IN LO terminal. This offset voltage has a range of 0 to
+1.2Vdc, measured with respect to TB1 terminal 2 (LO). It can be
used to null (or cancel) the effects of an input whose zero level is
not exactly zero volts. For example, adjusting R5 allows the display
to read “000” with an input whose lowest level is slightly above
zero volts. Please note, R5 cannot compensate for inputs whose
zero level is negative (i.e., if TB1 HI is more negative than TB1 LO).
3. Measuring Input Voltages Greater than 1.999Vdc (Use DMS-300 or DMS-30-1 Only): If possible, the resistors used for R1 and R2
should be ±1% metal-film types with TCR’s less than or equal to
100ppm/°C. More information on selecting 1% resistors can be found
in Application Note 14.
CAUTION: Do not apply inputs greater than +/-250Vdc.
1. Open SG10. For applications in which input voltages exceed
±100Vdc, also cut the 2 adjoining traces.
2. Configure the DMS-EB-AC/DC for span adjust using the procedure
previously outlined.
3. Calculate values for R1 and R2 as follows:
A typical value for R1 is 1MΩ. The sum of R1 + R2 should be
between 50kΩ and 10MΩ.
R2 = (FSI x R1) / ( |Vin| - FSI)
Where:
FSI = The attenuated voltage between the meter’s (–) IN LO and
(+) IN HI pins (pins 12 and 11, respectively) needed to achieve the
desired display readings
Vin = Input signal at TB1 terminals 1 and 2, disregarding polarity
Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000
MPM_DMS-EB-AC/DC.B01 Page 3 of 4
DMS-EB-AC/DC
100-264Vac Power Supply
Accessory Board for DMS-30PC/LCD Panel Meters
APPLICATIONS
1. Install R2: R2 = FSR / (IMAX . x 10000) where FSR is the desired
meter reading (0 up to 1999, disregarding any decimal points), and
IMAX is current in Amperes.
Example
Using a DMS-30-1 meter (+/-2V range), Vin is 0-5Vdc and the display
reading must be “000” to “1500”
2. Configure the DMS-EB for span adjust using the procedure previously outlined for the DMS-30-0 (+/-200mV range).
1. Assume R1 = 1.0MΩ.
2. R2 = (FSI x R1) / ( |Vin| - FSI)
R2 = (1.500 x 1,000,000) / (5.0 - 1.500)
R2 = 428,571Ω or 432kΩ
3. Apply the input signal (current) to TB1 (+) HI and (–) LO.
3. Calibrate the meter using a known voltage source. Adjust R4 to
compensate for tolerances in R1 and R2.
5. Enable the appropriate decimal point using SG1, SG2, or SG3.
4. Adjust R4 for desired full scale readings.
Example
4. DC Current Measurements (Use +/-200mV Range DMS-30-0
Meters):
Using a DMS-30-0 meter, a 0.100 Ampere input must read “100.0”
mA on the display.
When using R2 location for a dc current-shunt, please note that the
pc-board copper traces which short out R1 can only carry currents
up to 0.2A (200mA). However, dc currents up to 2A can be accommodated if a 20AWG jumper wire is soldered in location R1. Be sure R2
has a sufficient power rating to safely carry the full load current. Refer
to DMS Application Note 6 for more information on dc ammeters.
12
R2 = 1000 / (0.1 x 10000)
R2 = 1 Ohm
Enable DP3 via SG3 for a display reading of “100.0.”
R1
SG10
R5
12
R2
SG14
SG14
SG7
SG8
SG6
SG7
SG8
TB1
SG4 DP4
SG13
R4
TB1
SG4 DP4
SG11
SG11
SG13
R3
SG12
SG6
SG9
R3
SG12
1
HI(+)
2
SG9
1
LO(–)
HI(+)
Figure 3. R4 and R5 Installation
2
LO(–)
Figure 4. R1 and R2 Installation
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
12/30/08
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-AC/DC.B01 Page 4 of 4