Abstract: Flow restrictors for aircraft inlet acoustic cores, and associated systems and methods are disclosed. A system in accordance with one embodiment of the invention includes an inlet flow surface having multiple openings, and an acoustic treatment positioned adjacent to the inlet flow surface. The acoustic treatment can have multiple cells in fluid communication with the openings in the inlet flow surface. A fluid collector passage can be positioned to collect liquid entering the acoustic treatment through the multiple openings, and can have an exit aperture through which the liquid drains. The fluid collector passage can include at least one flow restrictor positioned to at least restrict the flow of air from the exit aperture through the fluid collector passage to the multiple openings.

Abstract: A scrambler circuit for digital telephony equipment receives a sequence of input bits, generates the sequence of output bits based on the input bits and stores the sequence of output bits. The generating of the sequence of output bits includes selecting at least one of the stored output bits in accordance with contents of a mask register, and applying a logic operation to a current input bit and the selected at least one stored output bit to provide a current output bit.