CPI CMP 200 Series Service Manual page 199

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