---------------------------------------------------------- Europa-List Digest Archive --- Total Messages Posted Fri 02/10/23: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:22 PM - How reliable is Factory Europa Fuel sender? (rparigoris) ________________________________ Message 1 _____________________________________ Time: 07:22:35 PM PST US Subject: Europa-List: How reliable is Factory Europa Fuel sender? From: "rparigoris" Hi Group We have a Europa Fuel sender on our mono. We had UMA build a nice fuel gauge with warning for the 9 positions. Range is .4 ohms empty and 190.7 ohms when full. I never quite understood how the 9 positions worked. Bill Daniels was kind enough to send me his old fuel gauge and sender. I figured if mine failed I would have a spare. How easy! Well of course instead of building aeroplane tonight, I had to test it and make sure it was working well. NOT!! Ended up it wouldn't read much below 1/2 tank and had some flakiness going on on the way up to full, or down from full. Can't have that. So managed to get it apart from the top and began troubleshooting. Think Applied Archaic Technology here, 1950s to be exact when you think of old original computer core memory. Well if it was good enough to get Apollo to the moon, it should be good enough to operate a Europoa Fuel gauge. But this one failed? OK here's how Europa designed it: they used special reed switches with what I suspect has a magnetic polarity, then they put a ferrite core on the outside of the reed switch. Now when the float that has magnets passes by the reed switch on the way to empty, it latches the reed switch to close the contacts and it stays closed because the polarity of the ferrite core is opposite that of the reed switch! Then when it passes on the way up to full, it demagnetizes the ferrite core and the switch opens. Each reed switch has a resistor across the terminals. Thus when you start opening the reed switches, you start adding the resistance together. OK now what happened: It appears that a rapid epoxy was used to hold the ferrite core to the glass reed switch. The position of the ferrite core is incredibly critical. Ends up the rapid epoxy is not a good choice as it failed and a number of them slid down due to gravity and stopped latching. I was able to tune them using a very mild magnet to get position optimized where they would easily latch and unlatch. Then when using the float magnets, they work really well. Instead of rapid epoxy, I used some non stink silicone to hold cores in position. Bottom line it now works great and I figured out how the thing works and I now have a spare. It seems unless who ever fabricated the fuel sender changed adhesive, they are at risk to go flaky. Figured i would share. Europa figured into the sender the shape of the fuel tank so they position the reed switches at 1/8 tank increments. When doing the repair I could see see the different spacing. Ron P. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=510140#510140 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message europa-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Europa-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/europa-list Browse Digests http://www.matronics.com/digest/europa-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.