DMS-20LCD-3-9-C Murata Power Solutions Inc, DMS-20LCD-3-9-C Datasheet - Page 3

• Manufacturer Part Number: DMS-20LCD-3-9-C
• Description: Digital Panel Meters Input Range +/-200V Power Source +9V
• Manufacturer: Murata Power Solutions Inc
• Type: 3 1/2 Digit, LCD Display Digital Panel Voltmeterr

Specifications of DMS-20LCD-3-9-C

• Equipment Type: 3 1/2 Digit, LCD Display Digital Panel Voltmeter
• Input: +/- 200 V
• Display Type: 3 - 1/2 Digit LCD
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: DMS-20LCD-3-9-C

4. BACKLIGHT (Pin 9) Function: Grounding pin 9 (i.e. connecting it to
5. Low Battery Annunciator: The “B” annunciator in the upper left-hand
6. Gain Adjust: There is a gain-adjust potentiometer on the back of each
7. Soldering Methods: All models in the DMS-20LCD Series easily
pin 3) turns on the backlighting LED’s. For non-backlit models, pin 9
has no internal connection. All backlit models include internal current-
limiting resistors. With nominal +5V or 9V supplies, backlit devices
typically draw 35mA of supply current. The current drawn by the back-
light (and therefore the current drawn by the meter) can be reduced by
installing a 1/4 Watt resistor between pins 3 and 9. The brightness of
the meter will be reduced proportionately.
9V-powered backlit models function with supply voltages up to +14V,
however, activating the backlight with voltages greater than 9.2V can
damage the meter. Therefore, a 1/4 Watt series resistor must be
installed between pins 3 and 9 in these situations. The value of the
series resistor is determined using the following formula:
point location pins should be left open. For 5V-powered models, the
decimal location pins are TTL compatible and may be hard wired as
described above or driven with 5V TTL logic gates.
corner of the display turns on when the supply voltage for 5V-powered
models falls below approximately +3.7V, or when the supply voltage for
9V-powered models falls below approximately 7.2V. However, the low-
battery annunciator’s turn-on threshold can vary signifi cantly from unit-
to-unit: as low as 2.7V for 5V-powered meters, and as low as 5.4V for
9V-powered models. Applications that use the LOW BAT annunciator
must be fully tested by the user, using a combination of low supply volt-
ages and the input signal’s minimum and maximum levels, to ensure
that all display readings are valid as long as the LOW BAT annunciator
remains off.
meter. It has approximately ±50 counts (±2.5%) range of adjustment.
Since these devices essentially have no zero/offset errors, a gain
adjustment is effectively an overall accuracy adjustment. Though they
may be performed at any point (except zero), accuracy adjustments
are most effective when performed with higher level input signals. The
circuit shown in Figure 9 provides ±10% range of adjustment.
withstand most common wave soldering operations. We recom-
mend, however, that you evaluate the effects your particular soldering
techniques may have on the meter’s plastic case and high-precision
electrical performance. We recommend the use of no-clean solders.
R
Example: If +BATTERY (pin 1 with respect to pin 3) is +12.6V,
R
R
Series
Series
Series
=
=
= 97 Ohms
+12.6 – 9.2V
+BATTERY – 9.2V
0.035
0.035
Ohms
Ohms
www.murata-ps.com/dpm
APPLICATIONS
DMS-20LCD meters are available in either 5V-powered or 9V-powered
models. 9V devices operate directly from 7.5V to 14V supplies (usually
batteries) without the need for external voltage regulators. 9V devices,
however, can not be used to measure voltages referenced to the negative
battery terminal (pin 3) because the minus input to the meter (pin 12, (–)
INPUT LO) must always be at least 1.5V above pin 3. 9V-powered meters
can only be used to make differential and not single-ended measurements.
5V-powered devices operate from any well-regulated +5V supply and will
accurately measure voltages both above and below pin 3 (5V RETURN) in
either single-ended or differential confi gurations.
1. Single-Ended Input Confi gurations: True single-ended measure-
8. Suggested Mating Connectors:
Panel mounted:
Board mounted:
ments can only be made with 5V-powered meters. The circuit of Figure
2 avoids problems normally associated with ground-loop currents.
Separate ground runs should be used for 5V RETURN (pin 3) and (–)
INPUT LO (pin 12).
Connector housing
Terminal type
Crimping tool
Wire size
Insulation diameter
Stripping length
Socket
3½ Digit, LCD Display Digital Panel Voltmeters
120 VAC
+
–
V
IN
AC to DC Converter
Figure 2. Single-Ended Input Confi guration
(–) IN LO
(+) IN HI
DMS-20LCD Series
(5V-Powered Models)
12
05 Apr 2011 MPM_DMS20LCD.B08 Page 3 of 6
11
+5V SUP
1
DATEL P/N 4320-01069-0
DATEL P/N 4400-01032-0
DATEL P/N 39-2099000
22 to 26 AWG
0.062” (1.57mm) maximum
0.100 to 0.125” (2.54 to 3.17mm)
DATEL P/N 4320-01074-0
DMS-20LCD-1-5
email: [e-mail]
6
DP1
3
5V RET
8
7
REF IN
REF OUT