Copyright PSC
2000781K MkII MLB Operating Procedure
Page 24 of 68
8.
Stowing the Lightband
This section will Stow the Lightband. During the Stow operation t
he Lightband’s internal switches experience
three collective switch states. Prior to Stowing, three test circuits will be operated to verify proper power and data
acquisition. Emulating each switch state reduces the probability of an anomaly. In order, the states are
1. Deployed (full voltage and current draw for entire duration)
2. Intermediate (full voltage and current draw for entire duration)
3. Stowed (no voltage or current draw as this state emulates the stow switches cut power)
8.1 Stow Test Circuit #1 (Deployed State)
Step
Procedure
Date & Initials
Tech.
QA
8.1.1
Oscilloscope shall record voltage and current per the following requirements:
1. Sample rate:
≥ 1,000 Hz
2. Voltage resolution:
≤ 0.2 V
3. Current resolution:
≤ 0.02 A
-----N/A-----
8.1.2
Set up the
Stow Power and Measurement Circuit
portion of
Stow Test Circuit
#1
per Figure 8-1.
8.1.3
Excessively long harnesses and/or thin wires have significant resistance which
will reduce the voltage at the motors. Verify the resistance between the power
source and Lightband connector is acceptable. This applies to the complete
loop (power and return). PSC recommends the following method
1. Ensure power source output is off.
2. Set the timer relay function to
‘D: One Shot’
and 5 s duration.
3. Set a DMM to measure resistance and connect it across the power
source.
4. Jumper pin 2 to pin 3 on a DB-9 socket connector and connect to the
Stow
Power and Measurement Circuit
.
5. Activate the timer relay and read the DMM resistance measurement. It
shall be < 1.0
Ω. This verifies the Motor A portion of the circuit.
6. Remove the pin 2 to pin 3 jumper and connect pin 6 to pin 7.
7. Activate the timer relay and read the DMM resistance measurement. It
shall be < 1.0
Ω. This verifies the Motor B portion of the circuit.
8. Remove the jumper connector and DMM.
8.1.4
Set up the
Test Circuit: Deployed
portion of
Stow Test Circuit #1
per Figure 8-1
and connect to the
Stow Power and Measurement Circuit
.
