Datenblatt-Suchmaschine für elektronische Bauteile
  German  ▼
ALLDATASHEETDE.COM

X  

AD693 Datenblatt(PDF) 10 Page - Analog Devices

Teilenummer AD693
Bauteilbeschribung  Loop-Powered 4-20 mA Sensor Transmitter
Download  12 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Hersteller  AD [Analog Devices]
Direct Link  http://www.analog.com
Logo AD - Analog Devices

AD693 Datenblatt(HTML) 10 Page - Analog Devices

Back Button AD693_15 Datasheet HTML 4Page - Analog Devices AD693_15 Datasheet HTML 5Page - Analog Devices AD693_15 Datasheet HTML 6Page - Analog Devices AD693_15 Datasheet HTML 7Page - Analog Devices AD693_15 Datasheet HTML 8Page - Analog Devices AD693_15 Datasheet HTML 9Page - Analog Devices AD693_15 Datasheet HTML 10Page - Analog Devices AD693_15 Datasheet HTML 11Page - Analog Devices AD693_15 Datasheet HTML 12Page - Analog Devices  
Zoom Inzoom in Zoom Outzoom out
 10 / 12 page
background image
AD693
REV. A
–10–
increasing the application voltages by adding resistance between
Pins 14 and 3 will decrease the temperature span.
An external voltage divider may also be used in conjunction
with the circuit shown to produce any range of temperature
spans as well as providing zero output (4 mA) for a non 0
temperature input. For example, measuring VX with respect to a
voltage 2.385 times the excitation (rather than 2 times) will
result in zero input to the Signal Amplifier when the RTD is at
100
°C (or 138.5 Ω).
As suggested in Table I, the temperature span may also be adjusted
by changing the voltage span of the Signal Amplifier. Changing the
gain from 2 to 4, for example, will halve the temperature span to
about 52
°C on the 4-20mA output configuration. (See section
“Adjusting Input Span.”)
The configuration for a three-wire RTD shown in Figure 17 can
accommodate two-wire sensors by simply joining Pins 1 and 5
of the AD693.
INTERFACING LOAD CELLS AND METAL FOIL STRAIN
GAGES
The availability of the on-chip Voltage Reference, Auxiliary
Amplifier and 3 mA of excitation current make it easy to adapt
the AD693 to a variety of load cells and strain gages.
The circuit shown in Figure 18 illustrates a generalized approach in
which the full flexibility of the AD693 is required to interface to a
low resistance bridge. For a high impedance transducer the
bridge can be directly powered from the 6.2 V Reference.
Component values in this example have been selected to match
the popular standard of 2 mV/V sensitivity and 350
Ω bridge
resistance. Load cells are generally made for either tension and
compression, or compression only; use of the 12 mA zero tap
allows for operation in the tension and compression mode. An
optional zero adjustment is provided with values selected for
+2% FS adjustment range.
Because of the low resistance of most foil bridges, the excitation
voltage must be low so as not to exceed the available 4 mA zero
current. About 1 V is derived from the 6.2 V Reference and an
external voltage divider; the Aux-Amp is then used as a follower
to make a stiff drive for the bridge. Similar applications with
higher resistance sensors can use proportionally higher voltage.
Finally, to accommodate the 2 mV/V sensitivity of the bridge,
the full-scale span of the Signal Amplifier must be reduced.
Using the load cell in both tension and compression with 1 V of
excitation, therefore, dictates that the span be adjusted to 4 mV.
By substituting in the expression, RS1 = 400 Ω/[(30 mV/S) – 1],
the nominal resistance required to achieve this span is found to
be 61.54
Ω. Calculate the minimum resistance required by
subtracting 10% from 61.54
Ω to allow for the internal resistor
tolerance of the AD693, leaving 55.38
Ω (See “Adjusting Input
Span.”) The standard value of 54.9
Ω is used with a 20 Ω
potentiometer for full-scale adjustment.
If a load cell with a precalibrated sensitivity constant is to be
used, the resultant full-scale span applied to the Signal Amplifier is
found by multiplying that sensitivity by the excitation voltage.
(In Figure 18, the excitation voltage is actually (10 k
Ω/62.3 kΩ)
(6.2 V) = 0.995 V).
THERMOCOUPLE MEASUREMENTS
The AD693 can be used with several types of thermocouple
inputs to provide a 4-20 mA current loop output corresponding
to a variety of measurement temperature ranges. Cold junction
compensation (CJC) can be implemented using an AD592 or
AD590 and a few external resistors as shown in Figure 19.
From Table II simply choose the type of thermocouple and the
appropriate average reference junction temperature to select
values for RCOMP and RZ. The CJC voltage is developed across
RCOMP as a result of the AD592 1
µA/K output and is added to
the thermocouple loop voltage. The 50
Ω potentiometer is
biased by RZ to provide the correct zero adjustment range
appropriate for the divider and also translates the Kelvin scale of
the AD592 to
°Celsius. To calibrate the circuit, put the
thermocouple in an ice bath (or use a thermocouple simulator
set to 0) and adjust the potentiometer for a 4 mA loop current.
The span of the circuit in
°C is determined by matching the
signal amplifier input voltage range to its temperature equivalent
Figure 18. Utilizing the Auxiliary Amplifier to Drive a Load Cell, 12 mA
± 8 mA Output


Ähnliche Teilenummer - AD693_15

HerstellerTeilenummerDatenblattBauteilbeschribung
logo
Analog Devices
AD693AD AD-AD693AD Datasheet
496Kb / 12P
   Loop-Powered 4.20 mA Sensor Transmitter
REV. A
AD693AD AD-AD693AD Datasheet
462Kb / 12P
   Loop-Powered 4??0 mA Sensor Transmitter
REV. A
AD693AE AD-AD693AE Datasheet
496Kb / 12P
   Loop-Powered 4.20 mA Sensor Transmitter
REV. A
AD693AE AD-AD693AE Datasheet
462Kb / 12P
   Loop-Powered 4??0 mA Sensor Transmitter
REV. A
AD693AQ AD-AD693AQ Datasheet
496Kb / 12P
   Loop-Powered 4.20 mA Sensor Transmitter
REV. A
More results

Ähnliche Beschreibung - AD693_15

HerstellerTeilenummerDatenblattBauteilbeschribung
logo
Analog Devices
AD693BQ AD-AD693BQ Datasheet
462Kb / 12P
   Loop-Powered 4??0 mA Sensor Transmitter
REV. A
AD693 AD-AD693 Datasheet
496Kb / 12P
   Loop-Powered 4.20 mA Sensor Transmitter
REV. A
AD421BNZ AD-AD421BNZ Datasheet
173Kb / 14P
   Loop-Powered 4 mA to 20 mA DAC
REV. C
AD421BRZRL AD-AD421BRZRL Datasheet
173Kb / 14P
   Loop-Powered 4 mA to 20 mA DAC
REV. C
AD421 AD-AD421 Datasheet
171Kb / 14P
   Loop-Powered 4 mA to 20 mA DAC
REV. C
AD421 AD-AD421_15 Datasheet
173Kb / 14P
   Loop-Powered 4 mA to 20 mA DAC
REV. C
logo
Schneider Electric
876CR SCHNEIDER-876CR Datasheet
126Kb / 1P
   Loop-powered transmitter with 4-20 mA and HART digital outputs for contacting conductivity sensors
Apr 26, 2022
logo
Analog Devices
AD5421 AD-AD5421_13 Datasheet
726Kb / 36P
   16-Bit, Serial Input, Loop-Powered, 4 mA to 20 mA DAC
Rev. F
AD5421 AD-AD5421_11 Datasheet
757Kb / 32P
   16-Bit, Serial Input, Loop-Powered, 4 mA to 20 mA DAC
REV. 0
logo
Agilent(Hewlett-Packard...
HCPL4100 HP-HCPL4100 Datasheet
230Kb / 12P
   Optically Coupled 20 mA Current Loop Transmitter
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12


Datenblatt Download

Go To PDF Page


Link URL




Privatsphäre und Datenschutz
ALLDATASHEETDE.COM
War ALLDATASHEET hilfreich?  [ DONATE ] 

Über Alldatasheet   |   Werbung   |   Kontakt   |   Privatsphäre und Datenschutz   |   Linktausch   |   Hersteller
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com