Copyright PSC
2000781K MkII MLB Operating Procedure
Page 26 of 68
Step
Procedure
Date & Initials
Tech.
QA
8.1.5
Set the power source voltage according to Lightband size:
Diameter < 31.0 inch:
27 to 28 V
DC
Diameter
≥ 31.0 inch and greater:
30 to 31 V
DC
8.1.6
Set the current limit on the power source to
6.5 ± 0.1 A.
8.1.7
Set the timer relay to apply power for
1.50 ± 0.05 s
.
If using the recommended timer, set its function to
‘D: One Shot’
.
8.1.8
Adjust oscilloscope to properly capture all channels. Verify
1. Current probe scale matches oscilloscope on Ch. 2 & 4 (10A/V on
oscilloscope & 100 mA/V on current probes)
2. Current probes are zeroed
3. Voltage scales on Ch. 1 & 3 (recommend 5 V/div)
4. Vertical positions on Ch. 1 & 3 (recommend zero at 1.5 div from bottom
of screen)
5. Current scales on Ch. 2 & 4 (recommend 500 mA/div)
6. Vertical positions on Ch. 2 & 4 (recommend zero at 1 div from bottom of
screen)
7. Horizontal time scale will capture entire duration (recommend 250
ms/div)
8. Horizontal trigger position (recommend 1 div from left of screen)
9. Vertical trigger level and channel (recommend Ch. 1 set to 2 V)
8.1.9
Perform the following to operate the test circuit.
1. Turn on the power source output.
2. Verify the oscilloscope trigger is active and ready to acquire data.
3. Activate the timer relay.
4. Verify the following occurred:
4.1. Voltage and current recorded per step 8.1.1
4.2. Measured voltage meets requirement in step 8.1.5 for Channels 1 & 3
4.3. Measured current values are approximately 1/10
th
of applied voltage
for Channels 2 & 4
4.4. Timer relay applies power per step 8.1.7
4.5. Data saves and is readable on a computer
5. If positions or scales were altered to examine data, ensure they are
returned to their original values.
6. Turn off the power source output.
If any parameters are not met, make the required changes and repeat this step.
Upon completion of this step, the
Stow Power and Measurement Circuit
shall
not be changed.
8.1.10
Remove the
Test Circuit: Deployed
portion of
Stow Test Circuit #1
in Figure
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