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1260-21 User Manual
Specifications 1-4
Racal Instruments
©
2005
Altitude
Operating
10,000
feet
Non-operating
15,000
feet
Power Requirements (with Option-01T)
+5V
0.541 A dynamic current
1.805 A peak current
+12V
3.000 A dynamic current
3.000 A peak current
Cooling (25% Relays energized operating at full rated current)
1.69 Liters/sec @ 0.113 mmH
2
O
Weight
with Option-01T
3.0 lbs. (1.361 kg)
w/o Option-01T
3.0 lbs. (1.361 kg)
MTBF (MIL-HDBK-217-FN2 method)
Excluding relays
1,500,000 hours
Including relays
280,000 hours
Relay Life Expectancy
Mechanical
5,000,000
operations
Electrical
10,000 operations at full load
Dimensions (Module)
C-Size, Single Slot VXI bus Module
Power
Dissipation
While the cooling of the 1260-21 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, power to the coils, the ambient temperature, and the
number of relays closed at any one time.
For example, if a 1260-21 module (containing 12 relays) has 3
relays closed, passing a current of 10 A, then:
Total power dissipation =
[(current)
2
* (path resistance) * 3 ] + (coil power * 3) +
(quiescent
power)