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29434 Application Note G123-821 Page 1 of 4: C70276 REV B 03.04
Mini DDV Amplifier
G123-821
3.2 Cooling
Vents in the top and bottom sides of the G123-821 case
provide cooling for the electronics inside. These vents should
be left clear. It is important to ensure that equipment below
does not produce hot exhaust air that heats up the G123-821.
3.3 Wiring
The use of crimp "boot lace ferrules" is recommended for the
screw terminals. Allow sufficient cable length so the circuit
card can be withdrawn from its case with the wires still
connected. This enables switch and capacitor changes on the
circuit card to be made while the card is still connected and
operating. An extra 100mm for cables going outside the
enclosure, as well as for wires connecting to adjacent DIN rail
units, is adequate. See section 6 for instruction on
withdrawing the circuit card from its case.
Terminal identification is on the block-wiring diagram on
page 3.
Application Notes
M
1. Scope
These application notes are a guide to applying the G123-821
Mini DDV Amplifier. They cover the following process:
Determine which input signal to use.
Provide an enable signal.
Determine required frequency response.
Draw your wiring diagram.
Install and commission your system.
Aspects such as hydraulic design, actuator selection and closed
loop design are not covered by these application notes.
2. Description
The G123-821 Mini DDV Amplifier is a ±1 Amp output
amplifier suitable for driving a Moog Mini DDV. Its bipolar
output enables the DDV to produce flow to both ports A and
B, an essential feature in a closed loop servo system.
Its intended application is to accept a command from a servo
amplifier output and produce a proportional ±1A output for
the coil of a Mini DDV. Three permanently connected input
signals are summed to produce the ±1A output. This feature
simplifies initial set up, the user needing only to connect to the
required terminals and set the 4-20mA switch on the circuit
board to the appropriate position.
When 4-20mA is selected, a wire break output is enabled and
will indicate if the input connection has been lost. The output
is normally on and turns off if a wire break is detected.
An enable input turns the output current amplifier on and off.
A user accessible plug-in capacitor sets the frequency response.
Front panel indicators and test points provide ease of set-up
and trouble shooting. The Mini DDV Amplifier is housed in a
compact DIN rail mounting enclosure and requires a 24V DC
power supply.
Refer also to data sheet G123-821.
3. Installation
3.1 Placement
A horizontal DIN rail, mounted on the vertical rear surface of
an industrial steel enclosure, is the intended method of
mounting. The rail release clip of the G123-821 should face
down, so the front panel and terminal identifications are
readable and so the internal electronics receive a cooling
airflow. An important consideration for the placement of the
module is electro-magnetic interference (EMI) from other
equipment in the enclosure. For instance, VF and AC servo
drives can produce high levels of EMI. Always check the
electro-magnetic compatibility (EMC) compliance of other
equipment before placing the G123-821 close by.
Top vents
Screw
terminals
1 - 8
Cover
release
tabs (2)
Screw
terminals
9 - 16
DIN rail
DIN rail
release
clip
Cooling
airflow
Bottom
vents
13
14
15
16
9
10
11
12
1
2
3
4
5
6
7
8 Page 2 of 4: C70276 REV B 03.04
cable gland
100mm Loop
Wires
Enclosure
Radial screen
termination
Cable
Grounded EMI
Preferred wiring
Cable gland
100mm Loop
Cable
Enclosure
Cable
Wire soldered
to screen
Drain wire.
or
(Heat shrink to
cover the screen)
Alternative wiring
Test Points
LEDs
Trim Pot
LEDs
Test Point
LK1 cuttable link
on reverse (solder) side
4-20mA
switch
ON
OFF
C13
3.4 EMC
Use high quality shielded cable to ensure emissions are below
the level needed for EMC compliance. Shield coverage of 96%
or greater is recommended. Immunity from external interfering
radiation is dependent on careful wiring techniques. The
accepted method is to radially terminate the cable screens, in
an appropriate grounded cable gland, at the point of entry into
the industrial steel enclosure. If this is not possible, chassis
ground screw terminals are provided on the G123-821.
Exposed wires should be kept to a minimum length. Connect
the screens at both ends of the cable to chassis ground.
4. Power Supply
24V nominal, 22 to 28V.
100mA @ 24V with all LEDs illuminated and no output load.
500mA @ 24V and ±1.0A Mini DDV load.
If an unregulated supply is used, the bottom of the ripple
waveform is not to fall below 22V.
5. Set-up
5.1 4-20mA switch
This switch is located on the circuit card. See section 6 for
instructions on withdrawing the circuit card. Set the switch to
on, if a 4-20mA input signal is connected. If not, set it to off. If
this switch is incorrectly set, the amplifier will not function
correctly.
5.2 Frequency response capacitor
This capacitor is mounted in plug-in sockets on the circuit card.
See section 6 for instructions on withdrawing the circuit card.
The value loaded at shipping is 2.2nF, which gives a 3dB point
of 482Hz. The capacitor can be changed to adjust the 3dB
point. C = 1061, C is in nano Farad (nF) and f is in Hertz (Hz).
f
The plug-in spacing is 0.2 inches (5mm) and a metallised
polyester film type with a tolerence of ±10% is suitable.
Roderstein MKT1826, Arctronic MKT185 or Wima FKS2 are
suitable types.
5.3 ±10V input resistance link LK1
The voltage input terminals 9 and 10 have a 10kOhm resistor
between them. This ensures that if an input wire breaks, the
G123-821 output drops to approximately zero. Without this
resistor, a wire break could result in just a minor degradation in
performance that may not be detectable to a person observing
the process being controlled by the G123-821. This 10k
resistor can be disconnected by cutting LK1 on the rear (solder)
side of the card. When disconnected, the input resistance goes
to 150k. Cut the fine trace between the two square pads with
a sharp packing knife.
5.4 ±10mA and ±10V unused input
An unused mA input can be connected to 0V or left floating.
To ensure best gain accuracy, leave it floating.
An unused V input must be connected to 0V.
6. Withdrawing the circuit card
from its case
To select 4-20mA input signal and to change the frequency
response setting capacitor, the circuit card needs to be
withdrawn from its case. To do this, push one tab in with a
pen or screwdriver while gently pulling on the top cover on
that side. The cover will release approximately 1 mm. Repeat
on the other side and withdraw the cover and circuit card until
the required adjustment points are exposed. The rigidity of the
connecting wires will hold the circuit card in position while
adjustments are made. Page 3 of 4: C70276 REV A 03.04
7. Block-wiring diagram
+15V
-15V
TP
Pow
er
Suppl
y
1
2
in
TP
LED
Vs
bac
k
s
hell
M
i
n
i
DDV
PLC
Out
put
5
D
A
+24V
+
0V
4
Supply
3
+24V
0V
w
i
re break
enable
*
not
e:
LK1 is
a c
u
t
t
able link
on t
he s
o
lder s
i
de of
t
he PC
B.
+/

10mA input
0V
+/

10V input
I
nput
s
0V
4-20m
A input
16
15
7
6
14
13
12
11
10
9
1R
4-20m
A
+
ON
+
OF
F
+
200R
+
150K
10K
LK1
150K
200R
200R
+
ze
r
o
in
LED
Dr
i
v
e
r
PW
M
+
out
TP
out
LED
enable
LED
+
+
+
+
C1
3
+
8 Page 4 of 4: C70276 REV B 03.04
Industrial Controls Division. Moog Inc., East Aurora, NY 14052-0018. Telephone: 716/652-3000. Fax: 716/655-1803. Toll Free 1-800-272-MOOG.
Moog GmbH. Germany. Telephone: 07031-622-0. Fax: 07031-622-100.
Moog Sarl. France. Telephone: 01 45 60 70 00. Fax: 01 45 60 70 01.
Moog Australia Pty. Ltd. Telephone: 03 9561 6044. Fax: 03 9562 0246.
Moog pursues a policy of continuous development and reserves the right to alter designs and specifications without prior notice. Information contained herein is for guidance only and does not form part of a contract.
Australia: Melbourne, Sydney, Brisbane Austria: Vienna Brazil: S
~
ao Paulo Denmark: Birkerød England: Tewkesbury Finland: Espoo France: Rungis Germany: Böblingen, Dusseldorf Hong Kong: Shatin India: Bangalore
Ireland: Ringaskiddy Italy: Malnate (VA) Japan: Hiratsuka Korea: Kwangju-Kun Philippines: Baguio City Singapore: Singapore Sweden: Askim USA: East Aurora (NY)
Internet Data
For a detailed Data Sheet and the latest version of these
Application Notes, please refer to the Moog website
www.moog.com/dinmodules
M
8. Specifications
Amplifier frequency response figures quoted using an
unpressurised Mini DDV D633-7205 as a load.
Command: All 3 inputs constantly summed to produce output
Each 100% input produces the maximum 1.0A
output
Input 1:
0 to ±10V for 0 to ±100% output
Differential
Input resistance, 10kOhm between the two input
terminals
Cuttable link to remove the 10kOhm to give
150kOhm
Input 2:
0 to ±10mA for 0 to ±100% output