---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 12/03/18: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 08:27 AM - Re: Fuse rating on AWG 20 wire with AeroLED strobes? (Robert L. Nuckolls, III) 2. 01:35 PM - Re: Fuse rating on AWG 20 wire with AeroLED strobes? (zwakie) 3. 02:28 PM - Re: Re: Garmin 335 Transponder Installation Manual (Alec Myers) 4. 02:35 PM - Re: Stall warning through Radio (user9253) 5. 02:52 PM - Re: Re: Stall warning through Radio (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 08:27:08 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: Fuse rating on AWG 20 wire with AeroLED strobes? At 10:40 PM 12/2/2018, you wrote: >When you say 'unlike circuit breakers'...what do you mean? Would >the CB trip more quickly than a fuse would blow, or would it be more >tolerant of what you're calling 'hammering'? Both devices operated based on temperature rise caused by current generated heating. Breakers are bi-metal 'thermostats' . . . they trip at a calibrated temperature which is NOT affected by previous excursions up to the edge of tripping. A CB is good for thousands of trip cycles with very little change in performance. Fuses are pieces of metal designed to heat up and melt at a predictable temperature. A characteristic that can be tailored to a current flow through the 'sensing' metal. But operating a fuse at its recommended 'limit' (75% of rating) produces SOME heating. This means that a fuse under normal load is already some way up the I(squared)R trip ladder when it is presented with transient 'overloads'. These little pushes into trip territory can cause mini-melts to occur in the fusible material which has the effect of lowering the fuse's rating. Repeated 'hammering' will seriously compromise predictability of that fuse to carry normal loads. When N811HB lost both ignition systems on base to the runway, the single fuse carrying BOTH ignition systems had been loaded to more than 75% on several occasions with short excursions to over 100%. Compromised fuse predictability combined with poor choices in architecture to kill the engine. >And your last statement 'there are no risks associated with >up-sizing the 20 AWG protection to the next level', do you mean >using a 10A fuse with 20 AWG, or are you saying to increase wire gauge to 18? '20AWG protection' is classically pegged at 7A. Raising it to 10A or even 15A in this situation will stand off the 'hammering' effects. It is not a risky thing to do. It will eliminate the possibility of nuisance tripping. Given that the lights do not represent a critical flight system, you could leave the 7A fuse in place and see how it goes. If you experience a nuisance trip, up-size the fuse. Let us know what you discover . . . Bob . . . ________________________________ Message 2 _____________________________________ Time: 01:35:33 PM PST US Subject: AeroElectric-List: Re: Fuse rating on AWG 20 wire with AeroLED strobes? From: "zwakie" I did a little experiment on Saturday after having finalized the wiring on my strobes. Specs ask for 5A fuse, so I put a 5A fuse in and lighted up the strobes. Having read this post on Friday night, I was expecting the fuse to blow, but I was very surprised to see that happen so quickly (literally well within 10 seconds). A 7.5A fuse did hold while keeping the strobes on for more than 2-3 minutes, but to be safe I 'upped' the fuse to 10A and will 'up' the two short leads from fuse block to switch to the beefy wiring that a previous owner has put in to match the 10A fuse. I will also review the determined fuse-sizes for other circuits that (can possibly) carry transient loads. This was an educational experiment.... ;) -------- Marcel Zwakenberg Europa XS TG || 912ULS || PH-SBR Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486118#486118 ________________________________ Message 3 _____________________________________ Time: 02:28:54 PM PST US From: Alec Myers Subject: Re: AeroElectric-List: Re: Garmin 335 Transponder Installation Manual I have a bunch of service manuals is there somewhere I can upload them for Bob? On Dec 2, 2018, at 1:45 PM, Robert L. Nuckolls, III wrote: At 06:42 AM 12/2/2018, you wrote: > > I just wanted to say thank you to a number of people who privately > sent me a variety of documents that will be extremely helpful > installing a Garmin 335 transponder. > > This list is a great resource for any required information !! > > Thanks ! > > Jeff Page > Dream Aircraft Tundra #10 > > Do not archive If persons in possession of such data would like to have it added to the archives on aeroelectric.com I would be pleased to receive them also . . . Bob . . . ________________________________ Message 4 _____________________________________ Time: 02:35:54 PM PST US Subject: AeroElectric-List: Re: Stall warning through Radio From: "user9253" There are lots of ways to make an alarm tone. The Forrest Mims Engineer's Notebook (my favorite book) has some circuits. https://www.zpag.net/Electroniques/Kit/The%20Forrest%20Mims%20Engineers%20Notebook.pdf On page 55 is a gated tone source. Grounding a pin on a 74LS368 turns on the tone. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486120#486120 ________________________________ Message 5 _____________________________________ Time: 02:52:49 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Stall warning through Radio At 04:35 PM 12/3/2018, you wrote: > >There are lots of ways to make an alarm tone. >The Forrest Mims Engineer's Notebook (my favorite book) has some circuits. >https://www.zpag.net/Electroniques/Kit/The%20Forrest%20Mims%20Engineers%20Notebook.pdf >On page 55 is a gated tone source. Grounding a pin on a 74LS368 >turns on the tone. Boy . . . there's a classic. I've recommended that publication dozens of times over the years. An excellent learning tool. Bob . . . ------------------------------------------------------------------------------------- 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.