---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 01/15/21: 13 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:49 AM - GTX-33 Installation Manual (fasilpereira) 2. 08:43 AM - Re: Alternator Ground (AdventureD) 3. 09:05 AM - Re: GTX-33 Installation Manual (user9253) 4. 09:50 AM - Re: GTX-33 Installation Manual (fasilpereira) 5. 01:22 PM - OV relay and crowbar (Dan Ballin) 6. 01:58 PM - Re: OV relay and crowbar (Jeff Luckey) 7. 02:12 PM - Re: OV relay and crowbar (Charlie England) 8. 02:16 PM - Re: OV relay and crowbar (Charlie England) 9. 02:21 PM - Re: OV relay and crowbar (user9253) 10. 02:41 PM - Re: Re: OV relay and crowbar (Charlie England) 11. 04:55 PM - Re: OV relay and crowbar (user9253) 12. 07:57 PM - Antenna Ground Planes (AdventureD) 13. 08:38 PM - Re: Antenna Ground Planes (user9253) ________________________________ Message 1 _____________________________________ Time: 03:49:50 AM PST US Subject: AeroElectric-List: GTX-33 Installation Manual From: "fasilpereira" I'm looking for the GTX-33 Installation Manual. Could anybody send me a copy of it to fasilpereira(at)yahoo(dot)com Thank you, Fabricio -------- Fabricio Pereira Engineer / Pilot Read this topic online here: http://forums.matronics.com/viewtopic.php?p=500244#500244 ________________________________ Message 2 _____________________________________ Time: 08:43:16 AM PST US Subject: AeroElectric-List: Re: Alternator Ground From: "AdventureD" [/quote] Correct. Both starter and alternator seek ground through their attachments to the engine. That fat/flexible jumper from crankcase to firewall ground stud is really important. Further, this alternator has a 2-terminal field connection. One of those terminals should be grounded to alternator case. Bob . . .[/quote] Interesting. I had simultaneously contacted Continental (It's an IO550), and they said to run a ground wire from a screw holding the (??alternator brush"") to the case. But if the alternator is already grounded via attachment to the case, why would that be needed? They did not mention grounding the second field terminal to the case. So now I'm confused :( Separately, the SD20 backup alternator field also has two leads and it takes a connector that I either lost or was not supplied with the alternator. (See attached pic). Anyone know where I can get that two lead connector? Maybe an auto parts shop? And does one of those wires ground to the alternator case? Read this topic online here: http://forums.matronics.com/viewtopic.php?p=500246#500246 Attachments: http://forums.matronics.com//files/alternator_field_connection_115.jpg ________________________________ Message 3 _____________________________________ Time: 09:05:12 AM PST US Subject: AeroElectric-List: Re: GTX-33 Installation Manual From: "user9253" Installation Manual http://www.aeroelectric.com/Installation_Data/Garmin/GTX%203X5%20Install%20Manual%20REV%205.pdf Maintenance Manual http://static.garmin.com/pumac/190-00734-11_07.pdf -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=500247#500247 ________________________________ Message 4 _____________________________________ Time: 09:50:47 AM PST US Subject: AeroElectric-List: Re: GTX-33 Installation Manual From: "fasilpereira" Thank you Joe! Fabricio -------- Fabricio Pereira Engineer / Pilot Read this topic online here: http://forums.matronics.com/viewtopic.php?p=500248#500248 ________________________________ Message 5 _____________________________________ Time: 01:22:48 PM PST US From: Dan Ballin Subject: AeroElectric-List: OV relay and crowbar I have an internally regulated Denso alternator on a Carbon Cub. I'd like some sort of OV protection and was looking at installing a Crowbar and OV relay. My question is do I need the relay? If I install the OV module (crowbar) on the Field wire (and ground), seems like when the voltage spiked, I'd cut the field current and hence the alternator output. Am I missing something??? Dan Ballin ________________________________ Message 6 _____________________________________ Time: 01:58:08 PM PST US From: Jeff Luckey Subject: Re: AeroElectric-List: OV relay and crowbar Dan, As you may already know, the Crowbar circuit is intended to blow the circui t breaker that feeds the regulator.=C2- The Crowbar fires, shorts the 5 a mp breaker to ground, pops the breaker and thus turns-off the regulator/alt ernator. What you are suggesting is interesting but will the field circuit in your r egulator tolerate being shorted to ground for a long period of time? -Jeff On Friday, January 15, 2021, 01:34:52 PM PST, Dan Ballin wrote: I have an internally regulated Denso alternator on a Carbon Cub.=C2- I'd like some sort of OV protection and was looking at installing a Crowbar and OV relay.=C2- My question is do I need the relay?=C2- If I install the OV module (crowbar) on the Field wire (and ground), seems like when the voltage spiked, I'd cut the field current and hence the alternator output.=C2- Am I missing something??? Dan Ballin - S - WIKI - - =C2- =C2- =C2- =C2- =C2- -Matt Dralle, List Admin. ________________________________ Message 7 _____________________________________ Time: 02:12:12 PM PST US Subject: Re: AeroElectric-List: OV relay and crowbar From: Charlie England On 1/15/2021 3:17 PM, Dan Ballin wrote: > > I have an internally regulated Denso alternator on a Carbon Cub. I'd > like some sort of OV protection and was looking at installing a > Crowbar and OV relay. My question is do I need the relay? If I > install the OV module (crowbar) on the Field wire (and ground), seems > like when the voltage spiked, I'd cut the field current and hence the > alternator output. Am I missing something??? > Dan Ballin Hi Dan, Unfortunately, yes. Most IR alternators place the regulator between the 'ground end' of the field winding and the ground itself. The 'high side' of the field winding is tied to the B lead output. That means that if the regulator's final 'output' transistor fails shorted, or any of the drive circuitry in the regulator fails in a manner that drives the output transistor to full conduction, there is no control over the alternator's output. The 'field' terminal on IR alternators is not a positive (meaning 'certain') control; think of it as more of a 'suggestion box' to the regulator. It is not connected directly to the field winding. So if you want positive control over the B lead output, you need the relay. There are internal mods you can do to the alternator to allow positive control, if you are motivated and are willing to develop the required skills. While I have the requisite skill-set, my personal preference for my IR alternator is to just use a B lead relay; this allows for quick/easy swap-out of the alternator, sourced from a convenient auto parts store, if I have a failure while away from home. Charlie -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 8 _____________________________________ Time: 02:16:36 PM PST US Subject: Re: AeroElectric-List: OV relay and crowbar From: Charlie England On 1/15/2021 4:09 PM, Charlie England wrote: > On 1/15/2021 3:17 PM, Dan Ballin wrote: >> >> I have an internally regulated Denso alternator on a Carbon Cub. I'd >> like some sort of OV protection and was looking at installing a >> Crowbar and OV relay. My question is do I need the relay? If I >> install the OV module (crowbar) on the Field wire (and ground), seems >> like when the voltage spiked, I'd cut the field current and hence the >> alternator output. Am I missing something??? >> Dan Ballin > Hi Dan, > > Unfortunately, yes. > Most IR alternators place the regulator between the 'ground end' of > the field winding and the ground itself. The 'high side' of the field > winding is tied to the B lead output. That means that if the > regulator's final 'output' transistor fails shorted, or any of the > drive circuitry in the regulator fails in a manner that drives the > output transistor to full conduction, there is no control over the > alternator's output. > > The 'field' terminal on IR alternators is not a positive (meaning > 'certain') control; think of it as more of a 'suggestion box' to the > regulator. It is not connected directly to the field winding. > > So if you want positive control over the B lead output, you need the > relay. There are internal mods you can do to the alternator to allow > positive control, if you are motivated and are willing to develop the > required skills. While I have the requisite skill-set, my personal > preference for my IR alternator is to just use a B lead relay; this > allows for quick/easy swap-out of the alternator, sourced from a > convenient auto parts store, if I have a failure while away from home. > > Charlie followup: Is this a 'homebuilt' install, or a Plane Power-branded Denso alternator? If it's a Plane Power, it likely has built-in OV protection, but as far as I know, Plane Power has never revealed their actual OV circuit. Charlie -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 9 _____________________________________ Time: 02:21:48 PM PST US Subject: AeroElectric-List: Re: OV relay and crowbar From: "user9253" Does an internally regulated alternator have a field wire? -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=500255#500255 ________________________________ Message 10 ____________________________________ Time: 02:41:58 PM PST US From: Charlie England Subject: Re: AeroElectric-List: Re: OV relay and crowbar On Fri, Jan 15, 2021 at 4:31 PM user9253 wrote: > > Does an internally regulated alternator have a field wire? > > -------- > Joe Gores No. (But you knew that, didn't you?) ;-) ________________________________ Message 11 ____________________________________ Time: 04:55:10 PM PST US Subject: AeroElectric-List: Re: OV relay and crowbar From: "user9253" Yes, the wire from a switch to an internally regulated alternator is a control wire. It enables the alternator. A crowbar module could be connected to the control wire. But if the internal regulator has failed, how do know that the control circuit has not also failed? A relay in series with the alternator output will open the output no matter what has failed inside of the alternator. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=500258#500258 ________________________________ Message 12 ____________________________________ Time: 07:57:43 PM PST US Subject: AeroElectric-List: Antenna Ground Planes From: "AdventureD" Here is a dumb question about ground planes. Does the ground plane serve to direct the signal to the antenna irrespective of whether the antenna is "connected" to the ground plane, or must the antenna itself be electrically connected to the ground plane? I am asking because the tech says the best approach to the ground plane in my e-glass composite is conductive paint on the belly. what I am wondering is how, after the conductive paint is painted over, one ensures that the antenna is "grounded" to the conductive paint ground plane. I think it may be the case that the ground plane has nothing to do with "grounding" the antenna to the ground plane, but rather that the purpose of the ground plane is to absorb signal for the antenna located in the middle of it (whether or not the antenna "touches" the ground plane. As you can see, I obviously don't know how antenna ground planes work. Appreciate your help, Dan Read this topic online here: http://forums.matronics.com/viewtopic.php?p=500260#500260 ________________________________ Message 13 ____________________________________ Time: 08:38:38 PM PST US Subject: AeroElectric-List: Re: Antenna Ground Planes From: "user9253" The ground plane does not have to be connected to the aircraft ground. But it does have to be connected to the coax shield at the antenna base. I doubt very much that conductive paint will work. Test the paint with an ohmmeter. Consider an internal antenna: http://www.aeroelectric.com/articles/Antennas/Morris_Com_Loop_Antenna.pdf There are other designs for internal antennas on fiberglass aircraft. Bob's book has a chapter on antennas. http://www.aeroelectric.com/Books/Connection/ -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=500261#500261 ------------------------------------------------------------------------------------- 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.