![]() |
Cost effective binary fuel pressure sensor?
I have two 5gal aux tanks that will pump into my main wet wings. Been running all over the internet looking for a low pressure fuel switch that I can T into the feed line to tell me when the line pump runs the aux tank dry. Just some simple "there is pressure/there isnt pressure" switch that I can hook an idiot light to, to tell me to shut the pump off. Not at all keen on a diaphram/contactor style sensor as is typical for oil pressure switches. Just seems like an explosion waiting to happen when used with fuel/fuel vapor.
I also looked at optical sensors, but they are some $200+ per, and the economical plastic Honeywell ones are metric threads so no joy on a T (though I could hog one out of brass if I have to). Anyone got any ideas? |
Like this? 80 PSI, 1/8?-27 NPT THREAD
|
Thats a piezo electric transducer, I'm pretty sure. It'll put out a varied voltage for a given pressure. I have no idea how to make that be a binary on/off 12v signal. I'm not a circuit guy or for sure I'd do it.
|
Diaphragm type switches are reliability used in aerospace applications. Stewart Warner/hobbs switches are used in many GA airplanes for fuel and oil pressure. Might give them a try.
|
Like the Honeywell contactor units, the Stewart Warner 5000 series only list oils and Jet fuels, not gasoline or combustible fuels. Maybe I'm being overly cautious, but I dont get a warm fuzzy about using them in a 100LL line.
|
That's a knockoff of the Kavlico; available in many different pressure ranges. Zero to ~4.5volts output at full scale. Google 'voltage comparator' to find a circuit that you can set to trip at the voltage of your choice.
Or, find an oil pressure sender for a car that uses an 'idiot light' instead of a gauge. But you'll need to run your transfer line at similar pressures to an oil pump on an engine. Optical sensors aren't always $200. http://www.ebay.com/itm/GEMS-ELS-950...AAAOSwh2xYB90M But...I contemplated doing it that way. If you insert it in a T fitting, the sensor T will probably need to be just above horizontal, so the fuel can cover the sensor cone while flowing, and drain away from it when the line empties. Charlie |
Check out Pillar Point... Their optical sensors work pretty well.
http://www.pillarpointelectronics.com/sensors.html |
Quote:
------- Looks like these guys had at one time (2003) a controller for the Facet cube pump to do exactly what I'm talking about, but Facet changed the pump design, so Pillar went with a more generic "controller" ala their existing off board set up......... Thanks again to DR and VAF for a great info resource. |
Quote:
http://www.omega.com/subsection/opti...FdgKgQodiQ4BoA |
Hi,
I'm using the optical sensors from Aircraft Extra, $51 cont. USA. http://www.aircraftextras.com/FuelSensor1.htm They are 12 mm diameter, sorry metric thread 100. Doc here: http://www.aircraftextras.com/Manual...Spec%20Sht.pdf I plan to mount on the fuel line. Hope this helps, |
Is there a particular pressure you are looking at for the light to come on? If not, what about one of the oil pressure switches like used for the HOBBS, I think those are set to around 5psi.
|
| All times are GMT -6. The time now is 11:56 PM. |