3D
AEC Calibration
CPI Canada Inc.
Use and disclosure is subject to the restrictions on the title page of this CPI document.
Page 3D-6
Rev. A CMP 200
®
Service Manual Ch # 901476-05
3D.2.2 AEC Board (Ion Chambers) Cont
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 that require a separate high voltage bias supply. R79 adjusts the value of the
+300 / +500 VDC, and the +45 VDC outputs, and should be set as per the ion chamber manufacturer
specifications.
Tables 3D-3 and 3D-4 show the pin outs for both the 9 pin D connectors and for the 12 pin in-line
connectors on the AEC board in figure 3D-2. The 9 pin connectors are compatible with most models of AID
ionization chambers. However, the installer should verify compatibility of the pin outs with the chamber(s)
being used.
FUNCTION PIN
NOTE
+300 VDC output
1
Only provided on configurations of this board that
require the +300 VDC output.
Left field select (refer to note below)
2
Middle field select
3
Reset / start
4
Chamber output
5
Right field select (refer to note below)
6
-12 VDC output
7
+12 VDC output
8
Ground
9
Table 3D-3: Pin outs for 9 pin D connector (J11 to J14)
NOTE:
Jumpers JW1 to JW8 swap the left and right fields on J11 to J14 as per the table below.
CHANNEL
LEFT / RIGHT FIELDS AS PER
TABLE 3D-3
LEFT / RIGHT FIELDS SWAPPED RELATIVE
TO TABLE 3D-3
1
Jumper JW7, JW8 pins 1-2
Jumper JW7, JW8 pins 2-3
2
Jumper JW5, JW6 pins 1-2
Jumper JW5, JW6 pins 2-3
3
Jumper JW3, JW4 pins 1-2
Jumper JW3, JW4 pins 2-3
4
Jumper JW1, JW2 pins 1-2
Jumper JW1, JW2 pins 2-3
FUNCTION PIN
NOTE
+500 VDC output
1
The +500, + or -300, and +45 VDC outputs are
+ or - 300 VDC output
2
only provided on configurations of this board
+45 VDC output
3
designed to interface to ion chambers requiring
+12 VDC output
4
these voltage outputs.
-12 VDC output
5
-24 VDC output
6
+12, -12, -24 VDC outputs are typically used as
Ground
7
the DC supply for a pre-amplifier, often part of
Reset / start
8
the ion chamber. -24 VDC is not available on
Right field select
9
CMP 200.
Middle field select
10
Left field select
11
Chamber output
12
Table 3D-4: Pin outs for 12 pin in-line connector (J1 to J4)
