Wasn't sure where to post this so here goes.
I want to build a stand alone circuit that i can use to trigger a relay when the line pressure on my LPG injectors drops below a (yet to be determined) threshold value.
The idea is that the relay will override the LPG master switch and cause the vehicle to fall back to Petrol running.
I have a spare MAP sensor lying around, is there anyway I can use this to drive such a circuit?
Key points I guess are:
1) The trigger value for firing the relay needs to be adjustable at the moment, until I can do some datalogging and determine what pressure drop causes AFR's to change too much and therefore need a switch back to petrol.
2) The MPX4250A needs a 5v input, so a voltage regulator will be required.
Any suggestions on which way to go are gratefully recieved.
Many thanks!
Simple pressure switch circuit using standard MS MAP sensor?
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- Super MS/Extra'er
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Re: Simple pressure switch circuit using standard MS MAP sen
Sounds like you're looking for a simple comparator circuit.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
Re: Simple pressure switch circuit using standard MS MAP sen
Thanks Matt, so from some googling something like an LM393 would be needed then?