DMS30DR MURATA [Murata Manufacturing Co., Ltd.], DMS30DR Datasheet - Page 5

• Manufacturer Part Number: DMS30DR
• Manufacturer: MURATA [Murata Manufacturing Co., Ltd.]

APPLICATIONS
6. Digital Ammeter: Digital ammeters are fi nding ever-increasing usage
4-20mA
85-264Vac
+
–
Example: For a meter with a 2V full scale input (1.999 full
scale reading) and a desired display reading of
"1000" (with an input of 20mA), V
To calibrate the circuit of Figure 7, perform the following:
1. With 4mA applied, adjust the 50kΩ potentiometer (R2) to
2. With 20mA applied, adjust the gain-adjust potentiometer on
because analog-style ammeters (moving-vane types) now cost roughly
the same as their digital counterparts. Additionally, analog ammeters
are not nearly as rugged as modern digital panel voltmeters. Figure 9
illustrates a typical ammeter application. The circuit uses a ±200mV
input meter — the preferred range for most ammeters — to measure
the voltage developed across a 0.1Ω current shunt. The circuit shown
display a reading of "000" (assuming that is the desired
reading).
the back of the meter to display a reading of "1000". For
different full scale readings, alter the value of R
AC to DC Converter
R1
R
R
Shunt
Shunt
ANA COMM
50k
(–) IN LO
Figure 7. 4-to-20mA Current Loop Operation
(+) IN HI
R2
= 1.000V/(0.020 – 0.004)A
= 1.000V/0.016A = 62.5 Ohms
11
10
12
1.225V
REF
9
Fsr
= 1.000 Volts
DMS-30DR-1
5V SUP
1
www.murata-ps.com
Shunt
5V RET
3
accordingly.
7
REF IN
8
REF OUT
7. External Gain Adjustment: Connect REFERENCE OUT
represents a basic ammeter connection diagram. A detailed application
note describing digital dc ammeters is available at www.cd4power.com.
(pin 8) to REFERENCE IN (pin 7) for normal, factory calibrated,
operation. Use the +1.225V REFERENCE OUT (pin 9) for applica-
tions needing external gain adjustment. Figure 10 shows the wiring
confi guration for each model. Calibration is performed with a precise,
near-full-scale, input voltage.
Technical enquiries email: [e-mail], tel:
Figure 8. Basic DC Ammeter Circuit
Sunlight Readable, 3½ Digit Panel Meters
Figure 9. External Gain Adjustment
DMS-30DR Series
with Auto-Dimming LED Displays
MPM_DMS-30DR.B04 Page 5 of 6
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