The question has arisen as to the necessity of sense lines on 
five volt switching power supplies.

Background:
Traditionally, we have designed our in-house power supplies with 
remote sense for the five volts output. We found this necessary 
because there was an appreciable difference between the voltage 
at the power supply and the voltage at the logic board, due to IR 
drop in the harness and in particular at the edge connector. As 
the board aged the voltage drop tended to get worse, due to dirt 
and wear on the edge connector.

In recent times we have learned to make shorter harnesses and use 
connectors more suitable for power connections at the logic 
board.

For example, on Gauntlet while drawing 5.5 - 6 amps, there is a 
difference of 90millivolts between the 5 volt power connections 
and the sense connections, measured at the power supply. This is 
not likely to change with age, as the connectors are better and 
tend to be self cleaning.

The question then is. At what load current do we need remote 
sense on purchased power supplies. We have a sample of a japanese 
switching supply rated at 10amps. It does not have remote sense.
It does have an accessable voltage adjustment pot. A similar 
model from the same company, rated at 20amps does have remote 
sense.

Do we require remote sense for:
     		all supplies
     		all supplies supplying more than 5 amps
     		all supplies supplying more than 10 amps
     		we don't need remote sense

Send your vote,comments,thoughts,suggestions,etc. to this address 
please.
     			Pat.