DMS-20PC-1-RL-C DATEL, DMS-20PC-1-RL-C Datasheet - Page 5

• Manufacturer Part Number: DMS-20PC-1-RL-C
• Description: Digital Panel Voltmeter
• Manufacturer: DATEL

Specifications of DMS-20PC-1-RL-C

• No. Of Digits / Alpha: 3.5
• Meter Function: DC Voltmeter
• Meter Range: ± 0V To ± 2V
• Digit Height: 9.4mm
• Operating Temperature Range: 0°C To +60°C
• Length/height, External: 20mm
• Accuracy: ± 1 Count
• Body Material: Polycarbonate
• Sample Rate: 2.5 Samples/sec
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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APPLICATIONS
DMS-20PC Series
To calibrate the circuit of Figure 7, perform the following:
Example: For a meter with a 2V full scale input (1.999 full scale
input of 20mA), V
6. Power Supply Monitoring: One of the most common digital panel
1.
display a reading of "000" (assuming that is the desired
reading).
2.
on the back of the meter to display a reading of "1000".
For different full scale readings, alter the value of R
accordingly.
meter applications involves monitoring the output voltage of the
system power supply — often this supply also powers the meter
itself. The low-power, red LED DMS-20PC-2-RL can be configured
to allow power supply monitoring over the range of 4.5-18Vdc. The
circuit in Figure 8 uses a low-drop-out, three-terminal regulator
(LM-2931Z-5, available from National Semiconductor) to provide
regulated 5V-power to the meter.
reading) and a desired display reading of "1000" (with an
4-20mA
85-264Vac
+
–
+
–
4.5 - 18Vdc
R
R
With 4mA applied, adjust the 50kΩ potentiometer (R2) to
With 20mA applied, adjust the gain-adjust potentiometer
Shunt
Shunt
AC to DC Converter
= 1.000V/0.016A = 62.5 Ohms
R1
= 1.000V/(0.020 – 0.004)A
Figure 7. 4-to-20mA Current Loop Operation
LM2931Z-5
IN
DMS-PS1-CM
Figure 8. 4.5-18V Power Supply Monitor
GND
Fsr
DATEL
OUT
= 1.000 Volts
ANA COMM
22µF
50k
10V
(–) IN LO
(+) IN HI
R2
11
10
12
+
+5V SUP
+5V SUP
DISP EN
5V RET
1
DMS-20PC-1
DP2
1
2
3
5
REF
2
DISPLAY
ENABLE
11
IN
7
DMS-20PC-2-RL
(+) IN HI
5V RET
3
Shunt
8
OUT
REF
8
REF OUT
7
REF IN
3 ½ D I G I T , L E D D I S P L A Y D I G I T A L P A N E L V O L T M E T E R S
12
(–) IN LO
8. External Gain Adjustment: Connect REFERENCE OUT
7. Digital Ammeter: Digital ammeters are finding ever-increasing
12
(pin 8) to REFERENCE IN (pin 7) for normal, factory calibrated,
operation. Use the circuit shown in Figure 10 for applications
needing external gain adjustment. Calibration is performed with
a precise, near-full-scale, input voltage.
The LM-2931 was chosen because it has the following on-chip
protection features: reverse polarity, short circuit and thermal
runaway. When using other, higher-power, DMS-20PC models
with three-terminal regulators, be sure to consult the regula-
tor manufacturer's data sheet to ensure the regulator is being
utilized safely and correctly.
usage 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 applica-
tion. 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 represents a
basic ammeter connection diagram. A detailed application note
describing digital dc ammeters is included in DATEL's new Digital
Panel Meter Databook.
CALIBRATOR
VOLTAGE
+
–
COM
OUT
5Vdc
Figure 10. External Gain Adjustment
1.5 Amp (Load Current)
Figure 9. Basic DC Ammeter Circuit
(–) IN LO
(+) IN HI
5V RET
+5V SUP
DISP EN
COMM
5V RET
11
D I G I T A L P A N E L M E T E R S
12
ANA
3
DP1
10
1
2
3
6
732, 1%
8.06k, 1%
(–) IN LO
DMS-20PC-1
NC
8
12
1
DMS-20PC-0
= 10 to 20 Turns
REF
IN
7
R
0.1W
0.150V
Shunt
200
MPM_DMS-20PC_C00
2k
1
1
1
+5V IN
17.4k, 1%
11
(+) IN HI
24.3k, 1%
(3.3 )
Load
W
8
REF OUT
7
REF IN
and ±200V models
Connections
for ±200mV
for ±2V, ±20V
Connections
models
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