Download RevF_093B

RTCA SC-135 and EUROCAE WG-14
Change Proposal Form
(One major comment per form.
Shaded blocks for committee use only.)
SC-135 Paper Number:
Date:
DO-160E/ED-14E Section:
Rev F #093B
17 March 2006
18
Author’s Name, Affiliation, and E-mail:
Paragraph:
Page:
John Birkland, Rockwell Collins Inc.
18.3.3
18-4
[email protected]
Reason for Change:
Have received several calls that Section 18 dwell times are too long. This proposal adds an option to
shorten the total test time without compromising the purpose of the long dwells.
Proposal Disposition:
Accepted As Written
Accepted As Modified
Withdrawn
X
Rejected
X
Other
Rejection Reason:
Proposal Deferred To:
For further consideration by WG-14, and RTCA Section 16 working Group
RTCA SC-135 Concurrence
EUROCAE WG-14 Concurrence
Proposal Disposition By:
Date:
Revise From:
No text is change or removed. Only an addition to the existing text is made. The location of the
addition is at the end of 18.3.3
It is assumed that the existing text has been corrected based in the previous proposal (author’s file
Section 18 2006_03_17 (01).doc).
Revise To:
As an option, the applicant may step per Table 18-1, or sweep per table 18-2. The dwell time for each
step shall be the longer of 3 seconds or the equipment response time. At each step record both applied
interference voltage and resulting ac current into the EUT. Divide the applied interference voltage by the
resulting ac current to generate an equivalent impedance. In addition, a 5 minute dwell is required at each
step or frequency where the equivalent impedance goes through a minima
Table 18.1 Step Sizes
Logarithmically spaced steps (fo is the test frequency)
Proposal Page Number:
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SC-135/ED-14 Change Proposal Form Rev E
Frequency Range
Max Step Size
Steps / decade
Min. # Steps in range
Total Step Dwell Time
10 Hz - 100 Hz
0.05 fo
49
49
2.5 min
100 Hz - 1 kHz
0.05 fo
49
49
2.5 min
1 kHz - 10 kHz
0.05 fo
49
49
2.5 min
10 kHz - 100 kHz
0.05 fo
49
49
2.5 min
100 kHz - 150 kHz
0.05 fo
49
10
0.5 min
Table 18.2 Sweep Rates
Analog (Continuous) sweeps
Proposal Page Number:
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SC-135/ED-14 Change Proposal Form Rev E
Frequency Range
Analog Maximum
Scan Rate
Actual
Scan Time
10 Hz - 100 Hz
0.333 Hz/sec
4.5 min
100 Hz - 1 kHz
3.33 Hz/sec
4.5 min
1 kHz - 10 kHz
33.3 Hz/sec
4.5 min
10 kHz - 100 kHz
333 Hz/sec
4.5 min
100 kHz - 150 kHz
3.33 kHz/sec
0.3 min
NOTE: If the system response time (Equipment under test and monitoring test equipment)
exceeds 3 seconds, than the dwell time must be increased to ensure the response is detected. The
analog scan rates must be adjusted accordingly. This can be achieved by multiplying the rates
(table above) by the factor (3 seconds / tr) where / tr is the response time in seconds. For example,
if tr is 30 seconds, (3 seconds / tr) is 0.1. The rate for the 1 kHz to 10 kHz range becomes
3.33 Hz/sec. The other ranges are handled in the same way.
Proposal Page Number:
3 of 4
SC-135/ED-14 Change Proposal Form Rev E
As Modified Text:
The dwell time based on power limit is not acceptable. It needs to be based on current peaks
(inflection points)
Roll comments from section 20 into this test.
Paul is suggesting that the dwell occur at each inflection point of the input current, not at
the power limit. Problems can occur at injection levels below the power limit.
Note: An inflection point is a point on a curve at which the sign of the curvature (i.e., the
concavity) changes.
Paul is also suggesting a compromise that this is an option for single phase and dc
equipment, not three phase.
John has asked Kamiar to provide documentation on why the test can not be done with the
proposed new test method.
Proposal Page Number:
4 of 4
SC-135/ED-14 Change Proposal Form Rev E