Technical data

1260-118/-118A User Manual Publication No. 980824-118 Rev. A
Specifications 1-4 Astronics Test Systems
Altitude
Operating 10,000 feet
Non-operating 15,000 feet
Power Requirements
+5 VDC 150 mA + 30 mA per energized relay
max.
Weight Current -118 -118A
9 oz. (260 g) 7 oz. (200 g)
Mean Time Between 783,668 hours (MIL-HDBK-217E)
Failures (MTBF)
Mean Time to Repair < 5 minutes
(MTTR)
Power
Dissipation
While the cooling of the Adapt-a-Switch carrier is dependent upon
the chassis into which it is installed, the carrier can normally
dissipate approximately 100 W. Care must be taken, then, in the
selection and loading of the plug-in modules used in the carrier. It
is not possible to fully load the carrier, energize every relay, and
run full power through every set of contacts, all at the same time.
In practice this situation would never occur.
To properly evaluate the power dissipation of the plug-in modules,
examine the path resistance, the current passing through the relay
contacts, the ambient temperature, and the number of relays
closed at any one time.
For example, if a 1260-118 module (containing 80 relays) has 25
relays closed, passing a current of 0.5 A, then:
Total power dissipation =
[(current)
2
* (path resistance) * 25 ] + (quiescent power)
By substituting the actual values:
Total power dissipation =
[(0.5 A)
2
* (1 Ω) * 25] + ( 0.75 W) = 7 W at 55°C