I am looking for a switch that can be operate by vacuum to turn an electric vacuum pump ( i have already ) on when the vacuum level goes down.
For another project i have, basically to created vacuum for brakes and then top up up as the brakes get used.
Most of what i have found on ebay are switches that when powered, open valve. i want it the other way round.
Anyone any ideas.
richard.

Would something like This do

Mike

[Edited on 19-7-2009 by miikae]