Lightband Electrical Verification - PSC 2000781J MkII MLB Operating Procedure

14. Lightband Electrical Verification

Measuring the electrical resistance of components in the Motor Bracket Assembly verifies Lightband functionality
and diagnoses potential problems. Take the measurements directly at the Lightband electrical interface (DB-9
socket connector). See Figure 16-2. Motor resistance may vary slightly depending on commutator position.
Contact PSC and do not operate the Lightband if any value is out of spec.
PSC recommends using a DMM. It will not cause damage to or operate the Lightband. If using a milliohm meter,
four wire Kelvin probe system, ensure the test current is <0.01 A to prevent rotating the motors.
Table 14-1: Motor Bracket Assembly resistance measurement (values apply only at NTP)
Lightband State
Stowed
Post
Set-For-Flight
Post Deploy
PSC Proprietary
Object Being Measured
Motor A
Motor B
Deploy Limit Switch A
Deploy Limit Switch B
Stow Limit Switch A
Stow Limit Switch B
Stow Limit Switch A
Stow Limit Switch B
Motor A
Motor B
Deploy Limit Switch A
Deploy Limit Switch B
Stow Limit Switch A
Stow Limit Switch B
Stow Limit Switch A
Stow Limit Switch B
Motor A Deploy Circuit
Motor B Deploy Circuit
Motor A
Motor B
Deploy Limit Switch A
Deploy Limit Switch B
Stow Limit Switch A
Stow Limit Switch B
2000781J MkII MLB Operating Procedure
Resistance [Ω]
Pin
Connections Allowable
2 , 4 8.0 to 11.0
6 , 8 8.0 to 11.0
1 , 2 < 0.3
5 , 6 < 0.3
3 , 4 > 1E6
7 , 8 > 1E6
4 , 9 < 0.3
8 , 9 < 0.3
2 , 4 8.0 to 11.0
6 , 8 8.0 to 11.0
1 , 2 < 0.3
5 , 6 < 0.3
3 , 4 > 1E6
7 , 8 > 1E6
4 , 9 < 0.3
8 , 9 < 0.3
1 , 4 8.0 to 11.0
5 , 8 8.0 to 11.0
2 , 4 8.0 to 11.0
6 , 8 8.0 to 11.0
1 , 2 > 1E6
5 , 6 > 1E6
3 , 4 < 0.3
7 , 8 < 0.3
Measured
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