DMS-20LCD-1-9B-C Murata Power Solutions Inc, DMS-20LCD-1-9B-C Datasheet - Page 4

• Manufacturer Part Number: DMS-20LCD-1-9B-C
• Description: Digital Panel Meters +-2 Volts/+9V Backlit Model
• Manufacturer: Murata Power Solutions Inc
• Type: 3 1/2 Digit, LCD Display Digital Panel Voltmeterr

Specifications of DMS-20LCD-1-9B-C

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

2. Differential Input Confi gurations: Differential measurements can be
3. Engineering Scaling: For measuring voltages greater than the full
APPLICATIONS
made with either 5V-powered or 9V-powered meters. Figure 3, though
not a practical real-world application, uses a voltage divider to demon-
strate the concept of a differential input signal. Be careful not to exceed
the ±2V common mode voltage limitation for 5V powered meters.
scale input range of a given meter, the input signal must be attenuated.
A simple voltage divider (similar to that shown in Figure 4) will scale
the input to within the range of the selected meter. R1 and R2 should
be precision, ±1%, metal-fi lm resistors with absolute TCR’s less than
50ppm/°C. See Ap Note 4 for more information on engineering scaling.
120 VAC
+
120 VAC
–
R1 + R2
V
50k: < R1 + R2 < 10M:
IN
R2
AC to DC Converter
Figure 3. Differential Input Confi guration
REF IN
REF OUT
R1
R2
AC to DC Converter
Figure 4. Input Attenuation Circuit
DP1
x V
(–) IN LO
(+) IN HI
8
7
6
+5V SUP
(5V-Powered Models)
IN
11
12
= Reading
1
+5V SUP
DMS-20LCD-1-5
DMS-20LCD-1-5
1
5V RET
3
5V RET
3
11
12
(–) IN LO
(+) IN HI
8
7
REF OUT
REF IN
www.murata-ps.com/dpm
R1
R2
R3
1k
1k
1k
4. Floating Signal Source Measurements: Floating signals can be
5. Process Control (4-to-20mA) Measurements: In many common
measured using the circuits shown in Figures 5 and 6. Figure 5 uses
a 5V-powered meter. Figure 6 uses a 9V-powered meter. Connecting
pin 10 (ANALOG COMMON) to (–) INPUT LO (pin 12) provides the
reference point for the meter’s input.
A “fl oating” input is a signal that has no galvanic connection to the
meter’s power supply. In the fi gures below, the 1.5V battery illustrates a
true fl oating input.
process-control applications, a 4-to-20mA current loop is used to
transmit information. Because DMS-20LCD meters have such high
input impedance, a simple shunt resistor across the meter’s input can
be used to convert the loop current to a voltage. See Figure 7. The
value of the shunt resistor is a function of the scaling requirements of
the particular application and can be calculated using the following
equation:
CELL
1.5V
CELL
1.5V
120 VAC
3½ Digit, LCD Display Digital Panel Voltmeters
+
–
–
AC to DC Converter
Figure 5. Floating Input Measurements
Figure 6. Floating Input Measurements
ANA COMM
(–) IN LO
(+) IN HI
(–) IN LO
BATTERY
(+) IN HI
DMS-20LCD Series
(5V-Powered Models)
(9V-Powered Models)
9V
12
11
10
+ BAT
11
12
+5V SUP
05 Apr 2011 MPM_DMS20LCD.B08 Page 4 of 6
1
1
DMS-20LCD-1-9
–
DMS-20LCD-1-5
3
–BAT
3
5V RET
email: [e-mail]
DP1
6
DP1
6
8
REF OUT
7
REF IN
8
7
REF IN
REF OUT