---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 04/10/23: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:42 AM - Interesting Carb temp anomaly (Alec Myers) ________________________________ Message 1 _____________________________________ Time: 06:42:35 AM PST US From: Alec Myers Subject: AeroElectric-List: Interesting Carb temp anomaly Any suggestions about this strange behaviour? I have a TC aircraft with a Lycoming O-320 engine, and it has a Marvel Schebler MA4 carb, in which is installed a regular B-5 positive temperature co-efficient temperature probe, connected to an instrument on the panel. When I switch on the instrument panel lighting in flight - the indicated carb temperature goes up - by typically 10 C. When I switch the instrument lighting off again - the indicated carb temperature goes up again - by another 10 C. It then seems to settle back down to its original value (about 20C lower) over the next few minutes. Some kind of grounding problem - instrument lighting circuit current being carried in the current loop for the temperature probe causing extra voltage drop somewhere - but why does the temperature go up even further when I shut off the instrument iighting? Does anyone have a clue? ------------------------------------------------------------------------------------- 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.