---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 04/11/15: 15 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:12 AM - coax routing (bob noffs) 2. 07:35 AM - Re: V-Charger (Eric M. Jones) 3. 08:09 AM - Re: coax routing (Robert L. Nuckolls, III) 4. 09:26 AM - Re: Re: V-Charger (Robert L. Nuckolls, III) 5. 10:28 AM - Re: coax routing (bob noffs) 6. 12:09 PM - Re: V-Charger (user9253) 7. 12:54 PM - Alternator field circuit breaker (Pete) 8. 01:09 PM - Re: Alternator field circuit breaker (B Tomm) 9. 01:23 PM - Re: Alternator field circuit breaker (Pete) 10. 02:31 PM - Re: Alternator field circuit breaker (Kent or Jackie Ashton) 11. 03:56 PM - Re: Shield grounds (user9253) 12. 04:15 PM - Re: Re: Shield grounds (Robert L. Nuckolls, III) 13. 04:53 PM - Re: Alternator field circuit breaker (user9253) 14. 08:37 PM - Re: USB Charger (speedy11@aol.com) 15. 09:20 PM - Re: Re: V-Charger (Eric Page) ________________________________ Message 1 _____________________________________ Time: 07:12:33 AM PST US Subject: AeroElectric-List: coax routing From: bob noffs hi all, routing my transponder and com coax. am i likely to pick up noise running them next to electric fuel pumps? thanks for any help. bob noffs ________________________________ Message 2 _____________________________________ Time: 07:35:16 AM PST US Subject: AeroElectric-List: Re: V-Charger From: "Eric M. Jones" http://www.alliedelec.com/carling-technologies-v-usb-24-g11-1bb1/70524982/ It's $55. Depending on who you are,it's either a deal or too pricey. Eric -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=440637#440637 ________________________________ Message 3 _____________________________________ Time: 08:09:48 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: coax routing At 09:06 2015-04-11, you wrote: >hi all, > routing my transponder and com coax. am i >likely to pick up noise running them next to >electric fuel pumps? thanks for any help. > bob noffs No Bob . . . ________________________________ Message 4 _____________________________________ Time: 09:26:02 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: V-Charger Virtually ALL 12 to USB charger products are crafted with some version of the switch-mode, buck converter design . . . Emacs! In recent years, the capability and sophistication of various step-down chargers has mushroomed. You see bins of cigar cigar lighter adapters at the cash register of convenience stores . . . priced from 4 to 10 dollars each. 5-pack-Dual-USB-2-Port-Universal-Car-Charger-DC-Adapter-5V-2-1A You can buy guts-only boards for this and similar products for as little as 50 cents per working item on ebay. Here's a 4-port, 5 Amp adjustable model you can buy for less than $5 mailed to your door. Emacs! The the technology to make these capable critters for so little money is gargantuan automated production volumes and minimizing parts count. These convertera all operated at 100 KHz up . . . some as high as one Mhz. Problem is that the waveforms are anything but sine-wave and exceedingly rich in harmonics. They are miniature rogue transmitters. The minimalist parts count philosophy encourages designers to discount if not totally ignore any potential for interference to other systems. FCC Part 15 rules allow extra-ordinarily antagonistic emissions with the admonition, "Users must discontinue use of this device if it interferes with other products or systems". The EASY work around is to craft a 14 to 5 volt step down regulator with linear components. Virtually noise free but the have to toss off a lot of heat. They are limited to 33% efficiency by design. Further, another feature in the USB charging cable protocols that can produce unexpected behaviors. For example, I used to have a cell phone that refused to accept power from an "unauthorized charger" . . . Turns out that SOME appliances expect to see SOME kinds of 'communication' from the charger in the form of treatment of the normally dormant data lines (The OTHER two wires in the usb cable). So even if you build yourself a noise-free linear, you may find that the target appliance rejects power from your handy-work based on a lack of proper hand-shake from the charger. I've not had time to dig into this deeply . . . perhaps someone on the List can enlighten us further. Given the limited, captive market that is aviation, commercial off the shelf USB charger products friendly to the cockpit will be pricey . . . even if the additional parts required are only a few cents cost. We had a gentleman here on the List perhaps a year ago who was striving to bring such a product to market. I helped him with the pennies-per-device additions necessary to do the filtering. The design was apparently satisfactory but I've not heard from him since as to his experience in the marketplace. This isn't a complex problem. The simple-ideas and their application supporting a successful design are well known. The problem is that folks who buy these devices at the convenience store cash register out-number us by about 100:1! Even the so-called 'noise free' chargers advertised only seem to speak to ripple voltage on the 5v output while ignoring or being oblivious to the potential for radio frequency emissions. Here's one article going to great lengths to talk about quality, safety and noise on output line with the word 'radio' appearing only once. http://tinyurl.com/bz4nv3y It's a wild and wooly USB world out there but not really difficult to thrive in. Bob . . . ________________________________ Message 5 _____________________________________ Time: 10:28:09 AM PST US Subject: Re: AeroElectric-List: coax routing From: bob noffs hot dog! thanks so much for the quick fix!. bob noffs On Sat, Apr 11, 2015 at 10:07 AM, Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > nuckolls.bob@aeroelectric.com> > > At 09:06 2015-04-11, you wrote: > >> hi all, >> =C3=82 routing my transponder and com coax. am i likely to pick up noise >> running them next to electric fuel pumps? thanks for any help. >> =C3=82 bob noffs >> > > No > > > Bob . . . > > =========== =========== =========== =========== > > ________________________________ Message 6 _____________________________________ Time: 12:09:40 PM PST US Subject: AeroElectric-List: Re: V-Charger From: "user9253" > you may find that the target appliance rejects > power from your handy-work based on a lack of > proper hand-shake from the charger. I've not had > time to dig into this deeply . . . perhaps someone > on the List can enlighten us further. http://tinyurl.com/Eric-Page-s-Post Message 7 -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=440659#440659 ________________________________ Message 7 _____________________________________ Time: 12:54:54 PM PST US From: Pete Subject: AeroElectric-List: Alternator field circuit breaker I am replacing the Nippon/Denso alternator in my RV9 with one from Plane Power. I did not build the RV. The field CB is rated at 10 amps. Plane Power calls for a 5 amp one. Any issue with using the existing 10 amp CB? Pete Hudes ________________________________ Message 8 _____________________________________ Time: 01:09:09 PM PST US From: "B Tomm" Subject: RE: AeroElectric-List: Alternator field circuit breaker Does the alternator have an internal regulator? Does it include a crowbar over voltage circuit? What size wire is running from the circuit breaker to the alternator? I would think you will want to follow the install guide closely. Bevan -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Pete Sent: Saturday, April 11, 2015 12:54 PM Subject: AeroElectric-List: Alternator field circuit breaker I am replacing the Nippon/Denso alternator in my RV9 with one from Plane Power. I did not build the RV. The field CB is rated at 10 amps. Plane Power calls for a 5 amp one. Any issue with using the existing 10 amp CB? Pete Hudes ________________________________ Message 9 _____________________________________ Time: 01:23:24 PM PST US Subject: Re: AeroElectric-List: Alternator field circuit breaker From: Pete Yes to both. Pete On Apr 11, 2015, at 1:07 PM, B Tomm wrote: > > Does the alternator have an internal regulator? Does it include a crowbar > over voltage circuit? What size wire is running from the circuit breaker to > the alternator? I would think you will want to follow the install guide > closely. > > Bevan > > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Pete > Sent: Saturday, April 11, 2015 12:54 PM > To: aeroelectric-list@matronics.com > Subject: AeroElectric-List: Alternator field circuit breaker > > > I am replacing the Nippon/Denso alternator in my RV9 with one from Plane > Power. I did not build the RV. > The field CB is rated at 10 amps. Plane Power calls for a 5 amp one. Any > issue with using the existing 10 amp CB? > > Pete Hudes > > > > > > > > ________________________________ Message 10 ____________________________________ Time: 02:31:21 PM PST US Subject: Re: AeroElectric-List: Alternator field circuit breaker From: Kent or Jackie Ashton Plane power depends on popping the 5A CB to provide the overvoltage protection. I would think using a larger CB will require more amps which might overheat your field wiring before popping a 10A breaker. Just a guess. http://plane-power.com/pdf/internally%20regulated%20experimental%20alternator%20information.pdf -kent > On Apr 11, 2015, at 4:22 PM, Pete wrote: > > > Yes to both. > > Pete >> On Apr 11, 2015, at 1:07 PM, B Tomm wrote: >> >> >> Does the alternator have an internal regulator? Does it include a crowbar >> over voltage circuit? What size wire is running from the circuit breaker to >> the alternator? I would think you will want to follow the install guide >> closely. >> >> Bevan >> >> -----Original Message----- >> From: owner-aeroelectric-list-server@matronics.com >> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Pete >> Sent: Saturday, April 11, 2015 12:54 PM >> To: aeroelectric-list@matronics.com >> Subject: AeroElectric-List: Alternator field circuit breaker >> >> >> I am replacing the Nippon/Denso alternator in my RV9 with one from Plane >> Power. I did not build the RV. >> The field CB is rated at 10 amps. Plane Power calls for a 5 amp one. Any >> issue with using the existing 10 amp CB? >> >> Pete Hudes > > > > > > ________________________________ Message 11 ____________________________________ Time: 03:56:54 PM PST US Subject: AeroElectric-List: Re: Shield grounds From: "user9253" Interesting discussion on VansAirforce Posted by Richard > General rule is: If you want to keep EMI inside the cable, ground both ends. If you want to keep the EMI outside the cable, ground one end. Reply by Louis > This isn't really the case. Terminating the shield at one point vs. multiple depends on the electromagnetic coupling mode you're trying to defend against (electric or magnetic)[1]. Electric coupling is a function of the capacitance across the insulator between the signal wire and the shield[2], while magnetic coupling is picked up by the loop formed by the cable and the ground plane[1]. > Low frequency signals interfere via magnetic coupling, and high frequency signals via electric[1][2]. Therefore, when trying to defend against low frequency interference (like when you're trying to protect a low frequency audio signal), you use single point shield termination to avoid creating a loop/current path for magnetic coupling to occur. For high frequencies, it's important to reduce the voltage accumulating on the shield, so multiple grounding points are used[2]. > > [1] Frbel, Anke. "Cable Shielding to Minimize Electromagnetic Interference." Cotbus University of Technology, Germany. > http://eeeic.org/proc/papers/55.pdf > > [2] Renner, E. NAVSO P-3181 Aircraft and Avionics Cabling E3 Design Manufacturing Guidelines. U.S. Navy, 1992 para 4.3 > http://bmpcoe.org/library/books/navso%20p-3181/53.html -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=440677#440677 ________________________________ Message 12 ____________________________________ Time: 04:15:41 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Shield grounds At 17:55 2015-04-11, you wrote: > >Interesting discussion on VansAirforce > >Posted by Richard > > > General rule is: If you want to keep EMI inside the cable, ground > both ends. If you want to keep the EMI outside the cable, ground one end. > "Keeping the EMI inside the cable" is the same task as "keeping the EMI from getting INTO the cable.:" Shielding can only break the electro-static coupling mode of transferring EMI from antagonist to victim . . . and shielding EITHER wire will do the task. Furhter, the currents that flow in the shield are exceedingly tiny . . . easy to calculate but very difficult to measure. Hence, the pig-tail that brings a shield to chassis ground COULD be a 40 AWG wire without degrading the shield's performance. Both of the documents cited use the term "EMI" and "shielded cable" but the discussions and energy propagation models immediately jump into the realm of transmission lines and frequencies of interest of a Mhz and up . . . Almost NONE of what is discussed in those papers applies to why wires may be shielded in light aircraft navigation and audio systems. If we were designing for resistance to nuclear EMP then the electro-magnetic coupling modes would have some significance . . . but understand also that the appliance designs and system integration problems go wAAAAYYyyyy beyond any fussing with shielded wires. I don't find much to argue with in those documents except that they don't apply to what we do. As cited many times in the past . . . follow the installation manual's instructions first. If there are doubts, determine IF the shield conductor is ALSO part of a signal/power path. If so attach both ends. If not, attach one end only. Bob . . . ________________________________ Message 13 ____________________________________ Time: 04:53:05 PM PST US Subject: AeroElectric-List: Re: Alternator field circuit breaker From: "user9253" The crowbar over-voltage circuit could be damaged by excessive current allowed by a 10 amp breaker. Use a 5 amp breaker. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=440681#440681 ________________________________ Message 14 ____________________________________ Time: 08:37:36 PM PST US From: speedy11@aol.com Subject: AeroElectric-List: Re: USB Charger Interesting to hear the squelch issues with cig lighter outlet USB chargers. I have two that I have used from Daytona Beach to Reno and back without any squelch issues. It is the Energizer model #PC-1CA. I use one for iPad and one for Stratus. Stan Sutterfield Reno Race 84 ________________________________ Message 15 ____________________________________ Time: 09:20:49 PM PST US Subject: Re: AeroElectric-List: Re: V-Charger From: Eric Page ------------------------------------------------------------------------------------- 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.