CPI Indico 100 Series Service And Installation Manual page 150

3D
AEC Calibration
3D.2.6 AEC Board (Ion Chambers) Cont
The following potentiometers are used for short AEC exposure time compensation:
•
R11 is used for channel 1 short exposure time compensation.
•
R12 is used for channel 2 short exposure time compensation.
•
R13 is used for channel 3 short exposure time compensation.
•
R14 is used for channel 4 short exposure time compensation.
R79 adjusts the output of the high voltage bias supply. This is only fitted on versions of this board intended for
use with ion chambers which require a separate high voltage bias supply. R79 adjusts the value of the +300
and/or the +500 and the +45 VDC outputs, and should be set as per the ion chamber manufacturer
specifications.
The following tables show the pinouts for both the 15 pin D connectors and for the 12 pin in-line connectors
on the AEC board in figure 3D-9.
FUNCTION
+300 or +500 VDC output
Not used
Right field select
Start command output
+45 VDC output
-24 VDC output
Signal input
Ground
Not used
Not used
Left field select
Middle field select
Ground
+12 VDC output
-12 VDC output
FUNCTION
+500 VDC output
+300 VDC output
+45 VDC output
+12 VDC output
-12 VDC output
-24 VDC output
Ground
Start command output
Left field select
Middle field select
Right field select
Signal input
Page 3D-16
PIN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Table 3D-6: Pinouts for 15 pin D connector
PIN
1
2
3
4
5
6
7
8
9
10
11
12
Table 3D-7: Pinouts for 12 pin in-line connector
Rev. D Millenia / Indico 100 Series Service Manual
NOTE
+500 and/or +300, and +45 VDC outputs are
provided on configurations of this board
designed to interface to ion chambers requiring
these voltage outputs only. Pin 1 will be wired
to supply +300 VDC OR +500 VDC, as per the
AEC chanber requirements.
NOTE
+500, +300, +45 VDC outputs are provided on
configurations of this board designed to
interface to ion chambers requiring these
voltage outputs only.
+12, -12, -24 VDC outputs are typically used as
the DC supply for a pre-amplifier, often part of
the ion chamber.
CPI Canada Inc.
Ch # 740904-06