Low profile battery pack with aircraft power provisions

摘要

A transportable power source (P) for an image viewing device (D) includes a battery pack housing assembly (10) to internally hold a first battery pack (12). An electrical interface circuit (14) receives an input voltage level (16) and provides a resulting output voltage level (18) as an output therefrom to operate the viewer device (D). The interface circuit (14) receives a selected first input voltage level (20) from the first battery pack (12). Alternatively, the interface circuit (14) receives a selected second input voltage level (22) from a power supply source (S) external to the battery pack housing (10). The interface circuit (14) further includes a switch (24) for selecting between sources of input voltage levels from among at least the first input voltage level (20) and the second input voltage level (22). The switch (24) also selectively controls the source for the resulting output voltage level (18).