---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 02/21/26: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:49 AM - Re: Fuel System Manager (911pete) 2. 07:49 AM - Re: Fuel System Manager (Eric Page) 3. 08:34 AM - Re: Fuel System Manager (911pete) 4. 08:41 AM - Re: Fuel System Manager (user9253) 5. 09:19 AM - Re: Fuel System Manager (911pete) 6. 11:29 AM - Re: Fuel System Manager (user9253) ________________________________ Message 1 _____________________________________ Time: 05:49:43 AM PST US Subject: AeroElectric-List: Re: Fuel System Manager From: "911pete" Food for further thought is that I will need another controller to manage the hydraulic system. It also used a PLC. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=516875#516875 ________________________________ Message 2 _____________________________________ Time: 07:49:51 AM PST US Subject: AeroElectric-List: Re: Fuel System Manager From: "Eric Page" Here's a quick conceptual doodle showing how the switch wiring might be done to handle OFF-MANUAL-AUTO switching, using a 2TL1-1 (or, for a much cheaper alternative, the B&C S700-2-1). Switched LPFS ground connection to be shared with HPFS using diode steering. AFC logic remains the hurdle... Read this topic online here: http://forums.matronics.com/viewtopic.php?p=516876#516876 Attachments: http://forums.matronics.com//files/switch_concept_287.jpg ________________________________ Message 3 _____________________________________ Time: 08:34:13 AM PST US Subject: AeroElectric-List: Re: Fuel System Manager From: "911pete" Not being an electronics guy my question is would latching relays utilizing the fuel sensors be a path to control the logic? Read this topic online here: http://forums.matronics.com/viewtopic.php?p=516877#516877 ________________________________ Message 4 _____________________________________ Time: 08:41:24 AM PST US Subject: AeroElectric-List: Re: Fuel System Manager From: "user9253" Pete, you wrote in a previous post, "The goal is to always keep the main tank full until the wings are empty". That seems reasonable. It is hard for me to understand how the fuel computer knows when to open and close the wing tank valves when there are only two level sensors in the main tank, high and low. It would not be desirable to let the main tank fuel level go down to the low level sensor before opening the wing tank valves. Suppose the computer closes the wing tank valves when the main tank is full. As fuel is used, the high level sensor tells the computer that the main tank is no longer full. The computer could then wait for a period of time, say 5 minutes, before opening the wing tank valves again. That time delay period needs to be short enough to keep the main tank relatively full. The time delay also needs to be long enough so as not to wear out the solenoid valves due to short cycling. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=516878#516878 ________________________________ Message 5 _____________________________________ Time: 09:19:15 AM PST US Subject: AeroElectric-List: Re: Fuel System Manager From: "911pete" I think you are mistaking where the low level sensor is. The main tank is approximately 75 gallons. The low level sensor is set at around the 60 gallon level. The plane burns 1.5 to 2 gallons per minute at non takeoff settings, so the valves would typically cycle every 7 to 10 minutes. If the fuel gets below the low level sensor for longer than 20 seconds the low level light would come on giving you around 30 minutes to land. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=516879#516879 ________________________________ Message 6 _____________________________________ Time: 11:29:31 AM PST US Subject: AeroElectric-List: Re: Fuel System Manager From: "user9253" OK, I modified my drawing in post number 5 by moving the lower fuel level sensor from the bottom of the tank to a higher position. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=516880#516880 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.