Amperage concerns on non-arduino power supply

Hi all,

Following from an earlier post, If I am running several servos etc. off of a separate power supply with a 5v BEC to regulate is 3amps too much ? I'm thinking of buying this BEC -

http://www.ebay.ie/itm/Hobbywing-3A-UBEC-5V-6V-max-5A-Lowest-RF-Noise-BEC-HW3ABEC-/270976446768?pt=UK_ToysGames_RadioControlled_JN&hash=item3f17747130#ht_2453wt_1110

But I'm worried that this kind of current running through things like sensors which will be returning a ping to the board might damage the input pins and the board.

Any advice appreciated

The current flow depends on resistance and voltage. As long as the voltage is correct (typically 5V for the Arduino) you can't hurt an input by having too much current available. You can connect an Arduino input to a 5V 50A power supply and not worry.