Hi Tony
If you were to have such a circuit, you would want to have it turn on second
pump
when it falls below ~ 2 PSI differential pressure (fuel pressure going to carb
less the airbox pressure).
I have series with bypass laid out fuel system and to me it makes sense to have
second pump running when having fuel pressure going low would be a bad thing,
like during take offs and landings. This may not be the thing to do if you have
parallel pumps because you can blow over the ~ 5 PSI differential.
UMA can provide an output from their differential gauge to drive a LED to
indicate
below ~ 2 or above ~ 5. You could probably modify signal or have them do it
to only provide below 2 and use that to turn on second pump. Their gauge is
driven by a differential pressure sender.
I will have a LED in my gauge to indicate above ~ 5 and below ~ 2.
Ron Parigoris
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=303465#303465
|