Functional Specifications

Ordering Information

DMS-EB-C

Application board with mating connector

and terminals

DMS-BZL1-C

DMS-30/40 bezel assembly

DMS-BZL2-C

DMS-30/40 bezel assembly with

sealing gasket

TECHNICAL NOTES

1. LCD Backlighting: For DMS-30LCD backlit models, close SG15. For

DMS-40LCD backlit models close SG18. See the DMS-30LCD or the

DMS-40LCD data sheets for limitations on backlighting 9V-powered

meters.

2. 9V-Powered, LCD Display Models: DMS-30LCD-X-9 and DMS-

40LCD-X/X-9 meters cannot be used in single-ended input configura-

tions, i.e., LO (J1, pin 2) cannot be connected to GND (J1, pin 6). When

operating from a 7.5 to 14Vdc power source with a single-ended

input, use a +5V-powered meter and install U1 (see Battery Operation

section and Technical Note 4).

Input Supply Range

See applicable meter's data sheet

Input Supply Range

U1 (LM7805CT) Installed:

DMS-30/40PC-X-XS

+7.5 to +12.6V

DMS-30/40PC-X-XL

+7.5 to +18.0V

DMS-30/40LCD-X-5

+7.5 to +32.0V

DMS-30/40LCD-X-5B

+7.5 to +12.6V

Operating and Storage Temperature

See applicable meter's data sheet

Humidity

0 to 95%, non-condensing

Dimensions

2.02" (51.31mm)L x 0.83" (21.08mm)W

J1 Connector & Wire Information

Terminal Type

DATEL P/N 4400-01032-0

Crimp Tool

DATEL P/N 39-2099000

Wire Size

22 to 26 AWG

Insulation Diameter

0.062" (1.57mm) max.

Stripping Length

0.100" to 0.125" (2.54 to 3.17mm)

Introduction

As shipped, the DMS-EB is configured for 5V-powered DMS-30 3½

digit meters operating in the single-ended mode (SG5 closed) using the

meter's internal reference (SG13 closed). This configuration is the most

common and works well for most simple voltage measurements.

Many of the applications described below apply to both DMS-30

and DMS-40 meters. However, Application 5, installing the span (R4) and

offset (R5) adjust potentiometers, can only be used with DMS-30 meters.

Also note that some of the other applications require the installation of

R4 and R5. See Technical Note 5 when using the DMS-EB with DMS-40

meters.

Please read all of the following technical notes and perform any

required modifications before soldering the DMS-EB onto the meter

(aligning pin 1 to pin 1). After soldering, carefully connect +5Vdc to +V

(J1, pin 5) and power return to –V (J1, pin 6).

Close SG6 when measuring floating inputs with a 9V-powered meter

(floating inputs are described in Technical Note 7). SG6 provides a bias

reference for the input signal by tying LO to the meter's Analog Com-

mon terminal (pin 10).

3. Input Resistor Dividers: Use 1%, or better, metal film resistors for

R1 and R2 in DMS-30 applications, and 0.5%, or better, in DMS-40

applications. Using tight-tolerance resistors in input divider networks

allows most final calibration adjustments to be made with the meter's

rear calibration pots through the access holes provided. Make sure

the resistor power and voltage ratings are adequate for the given

application.

4. Using U1 (LM7805CT): The power supply voltage range listed in the

Battery Operation section is rated for a 150mA LED meter or a 35mA

backlit LCD meter. A 10μF/35V tantalum capacitor (C2) should be

installed with the polarized end next to the + symbol on the DMS-EB.

This is especially important if the power supply is located far from U1.

5. DMS-40 Meters: When the DMS-EB is used with DMS-40PC or DMS-

40LCD meters, be sure to open SG13. The RN-DMS resistor acces-

sory kit comprised of resistor R3 and potentiometers R4 (Gain/Span)

and R5 (Offset/Zero), cannot be used with DMS-40 series meters. To

change the input range on DMS-40LCD meters from the low range to

the high range, close SG16.

6. Calibration Potentiometer Adjustment Holes: Two overlapping

holes on the DMS-EB provide access to the ¾-turn calibration poten-

tiometer on DMS-30 meters and the 3-turn potentiometer on DMS-40

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.

7. Input Configurations: The DMS-EB is supplied with SG5 closed. SG5

connects J1, pin 2 (LO) to power return J1, pin 6 (GND) and configures

the meter for single-ended operation, that is, the low side of the input

is at system ground or zero Volts. SG5 must also be closed when

measuring floating inputs. Floating inputs are signals which have no

electrical connection, or reference to, the power supply which powers

the meter.

In applications in which input LO is connected to ground elsewhere in

the system, and SG5 is closed, unwanted ground-loop induced display

errors may develop. Ground loops, a condition in which display drive

currents also flow through the input signal wiring, can cause unstable

display readings. If this occurs, try opening SG5 to see if the display

stabilizes.

SG5 must be open when measuring differential inputs that are refer-

enced to the same supply which powers the meter. DMS Application

Note 2 (Input Configurations, Power Supplies and Ground Loops)

provides a detailed discussion of input configurations.

8. Soldering: DATEL recommends the use of "no-clean" solders when

installing or making modifications to the DMS-EB.

DMS-EB

Multi-Purpose Application Board for DMS-30 & DMS-40 Series Meters

www.murata-ps.com

MPM_DMS-EB.B01 Page 2 of 4