ak45c-048l-050f20han-8 Astec Powe, ak45c-048l-050f20han-8 Datasheet - Page 13

• Manufacturer Part Number: ak45c-048l-050f20han-8
• Description: 36 Vdc To 75 Vdc Inputs, 100 W America, Inc
• Manufacturer: Astec Powe

Technical Reference Notes (TRN)
Thermal Considerations
The power converter operates in a variety of thermal environments: however, sufficient cooling
should be provided to help ensure reliable operation of the converter. Heat-dissipating
components are thermally coupled to the case. Heat is removed by conduction, convection, and
radiation to the surrounding environment. Proper cooling can be verified by measuring the case
temperature.
Heat Transfer Characteristics
Increasing airflow over the converter enhances the heat transfer via convection. Figure 14 shows
the maximum power that can be dissipated by the converter without exceeding the maximum
case temperature versus local ambient temperature (T
(400 ft/min).
Systems in which these converters are used generate airflow rates of 0.25 m/s (50 ft/min) due to
other heat dissipating components in the system. Therefore, the natural convection condition
represents airflow rates of approximately 0.25 m/s (50 ft/min). Use of Figure 14 is shown in the
following example.
Example
What is the minimum airflow required for an 033F20 operating at 48 V, an output current of 15 A,
and maximum ambient temperature of 50 ºC.
Solution:
_____________________________________________________________
ASTEC POWER - Andover
Given: Vi = 48 V, Io = 15 A, T
Determine P
Determine minimum airflow (Figure 14): v = 1.0 m/s (200 ft/min)
20
18
16
14
12
10
8
6
4
2
0
* longitudinal airflow, transverse airflow is more efficient and extends
calculated maximum ambient by 5 °C
25
D
30
(Figure 17): P
Figure 14. Forced Convection Power Derating
35
40
45
D
A
= ~8 W.
Power Derating Curve*
= 50 ºC.
Ambient Temperature (ºC)
50
AK45C SERIES
55
60
65
A
) for natural convection through 2.0 m/s
36 Vdc to 75 Vdc Inputs, 100 W
70
75
80
2.0 m/s (400 ft/min)
1.5 m/s (300 ft/min)
1.0 m/s (200 ft/min)
0.5 m/s (100 ft/min)
Nat. Conv.
85
AK45C 100W Series
90
95 100
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