---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 03/12/09: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:00 AM - Re: Re: Polyfuses (RV Builder (Michael Sausen)) 2. 07:04 AM - FW: AeroElectric-List Digest: 9 Msgs - 03/11/09 (Emrath) 3. 07:20 AM - Re: FW: AeroElectric-List Digest: 9 Msgs - 03/11/09 () 4. 07:23 AM - Re: FW: AeroElectric-List Digest: 9 Msgs - 03/11/09 (Etienne Phillips) 5. 09:57 AM - Re: FW: AeroElectric-List Digest: 9 Msgs - 03/11/09 (F. Tim Yoder) 6. 05:12 PM - Re: Re: Polyfuses (Robert L. Nuckolls, III) 7. 06:05 PM - Re: Re: Polyfuses (RV Builder (Michael Sausen)) ________________________________ Message 1 _____________________________________ Time: 06:00:31 AM PST US From: "RV Builder (Michael Sausen)" Subject: RE: AeroElectric-List: Re: Polyfuses Let me see if I can refresh your memory. Because of the undocumented crowbar "feature" in the LSE ignitions that came to light recently, you had suggested using a relay to provide power to an unprotected wire in the case of a rear mounted battery. The concern was that the LSE could cause a trip/blow in an OV situation however the ignition would be fine and require a reset. In a rear mounted battery the only way to accommodate this need to reset was to put a breaker up on the panel but this left an unprotected line from the battery to the CB. You suggested a standard relay would be the best way to address this and I didn't like the additional complexity in addition to replacing one potential failure mode with another. It seems to me that a Polyfuse would address the need to reset a nuisance trip and allow the protection to stay back by the battery without needing to add relays (more wires, additional failure points, and additional switches) or big fuses/fat wires to get a CB up within arm's reach. Michael -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Wednesday, March 11, 2009 11:12 PM Subject: RE: AeroElectric-List: Re: Polyfuses At 10:30 PM 3/9/2009, you wrote: >Sausen)" > > So here's a thought then for a potentially suitable application > for these little monsters where there is some $value$. Ignoring > the fact that these are surface mount creatures and a suitable and > robust mounting mechanism would be needed, what about a scenario > where you have a rear mounted battery and need to protect a wire in > which a fuse would not be useable. Say if a device has a low power > requirement but for some reason has a crowbar circuit in it like > maybe a Lightspeed ignition. :P > > Like I said before, I'm not keen on using a relay as that is > nothing more than a workaround in my mind and introduces a whole > new failure mode plus a bunch of additional wiring. The self > resetting nature of the Polyfuse wouldn't be a big deal as I would > still want a master switch on each LSE. Checklist item would be > the best solution to addressing when to reset a "blown" > ignition. More importantly it would allow the crowbarred (is that > a word) ignition to be reset without the need to access a > inaccessible fuse/breaker or use a relay to shoe horn a breaker > into an accessible location. > > So can someone tell me why this would not work to address the > recent revelations around LSE's? I still would rather use a fuse > or breaker but it seems to be as good or better than some of the > other alternatives (big wire, relay). I think I'm lost. How would the polyfuse facilitate an alternative to big wires and/or relays? I don't recall a conversation about relays except for heavy duty alternate feed paths for the e-bus. I'm not seeing your point about a polyfuse being more attractive than a fuse or breaker in the same slot. Can you enlighten me? Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 2 _____________________________________ Time: 07:04:33 AM PST US From: "Emrath" Subject: AeroElectric-List: FW: AeroElectric-List Digest: 9 Msgs - 03/11/09 I appreciate the replies from David and Bill. Yes this is the XM antenna and there is no magnet in my version of this antenna. There are two small holes for mounting but a 4-40 cross threads in the hole after a turn to 1.5 turns. So what I need must be metric about the same size as a 4-40 in dia. but with different TPI. I am not concerned with using this is a "buddy's" plane at this time, but it would not be too hard to modify the mounting later as I can get to my glare shield underside rather easy to unscrew these little buggers. Marty Time: 01:58:48 PM PST US From: "Emrath" Subject: AeroElectric-List: Garmin weather antenna I have a Garmin Weather antenna for my GPSMAP 496 which I would like to mount on top of my panel. There are two threaded holes in the back of the antenna to be able to bolt this to the 'dash'. Does anyone know what size screws are required to do this, I cannot seem to find any reference in my materials about this. Marty ________________________________ Message 6 _____________________________________ Time: 02:37:16 PM PST US From: "David LLoyd" Subject: Re: AeroElectric-List: Garmin weather antenna Marty, Do you know if your weather antenna is the model that has the ring magnet on the bottom...? If so, you may not want to mount it to the panel top if you have a compass near by. Also, you may not want to permanently mount it in case you want to take the antenna with you to hook up to another Garmin in a buddy's plane. There is a procedure for removing the magnet if it is not desired. Some of us have mounted the antenna high up and out of the way in the front window frame area using an "L" shaped bracket. The 2 screws holding it can be quickly removed in the case where you want to use the antenna in another aircraft. ......2 cents of comment.... David ________________________________ Message 8 _____________________________________ Time: 07:11:26 PM PST US From: "Bill Hibbing" Subject: Re: AeroElectric-List: Garmin weather antenna I have a 396 and if the antenna you're talking about is for the XM weather I'm pretty sure that the screws are 4-40. What I did to make it easy to remove the antenna was cut the head off the screw and then sharpen it up a little. I then drilled holes in the top of the glareshield using the mounted screws to mark the spot to drill and set the antenna with screws attached into the holes. I've been using it this way for a couple of years now and have never had a problem of the antenna coming off the glareshield in turbulence. Oh yeah, I used as small a drill as possible so that the fit was fairly snug. Bill Glasair SIIS-FT ________________________________ Message 3 _____________________________________ Time: 07:20:14 AM PST US From: Subject: Re: AeroElectric-List: FW: AeroElectric-List Digest: 9 Msgs - 03/11/09 Maybe you should use the famous aviation product-velcro for relative ease of operation. Ron Burnett RV-6A finishing H-4 Esubbie powered ---- Emrath wrote: ============ I appreciate the replies from David and Bill. Yes this is the XM antenna and there is no magnet in my version of this antenna. There are two small holes for mounting but a 4-40 cross threads in the hole after a turn to 1.5 turns. So what I need must be metric about the same size as a 4-40 in dia. but with different TPI. I am not concerned with using this is a "buddy's" plane at this time, but it would not be too hard to modify the mounting later as I can get to my glare shield underside rather easy to unscrew these little buggers. Marty Time: 01:58:48 PM PST US From: "Emrath" Subject: AeroElectric-List: Garmin weather antenna I have a Garmin Weather antenna for my GPSMAP 496 which I would like to mount on top of my panel. There are two threaded holes in the back of the antenna to be able to bolt this to the 'dash'. Does anyone know what size screws are required to do this, I cannot seem to find any reference in my materials about this. Marty ________________________________ Message 6 _____________________________________ Time: 02:37:16 PM PST US From: "David LLoyd" Subject: Re: AeroElectric-List: Garmin weather antenna Marty, Do you know if your weather antenna is the model that has the ring magnet on the bottom...? If so, you may not want to mount it to the panel top if you have a compass near by. Also, you may not want to permanently mount it in case you want to take the antenna with you to hook up to another Garmin in a buddy's plane. There is a procedure for removing the magnet if it is not desired. Some of us have mounted the antenna high up and out of the way in the front window frame area using an "L" shaped bracket. The 2 screws holding it can be quickly removed in the case where you want to use the antenna in another aircraft. ......2 cents of comment.... David ________________________________ Message 8 _____________________________________ Time: 07:11:26 PM PST US From: "Bill Hibbing" Subject: Re: AeroElectric-List: Garmin weather antenna I have a 396 and if the antenna you're talking about is for the XM weather I'm pretty sure that the screws are 4-40. What I did to make it easy to remove the antenna was cut the head off the screw and then sharpen it up a little. I then drilled holes in the top of the glareshield using the mounted screws to mark the spot to drill and set the antenna with screws attached into the holes. I've been using it this way for a couple of years now and have never had a problem of the antenna coming off the glareshield in turbulence. Oh yeah, I used as small a drill as possible so that the fit was fairly snug. Bill Glasair SIIS-FT ________________________________ Message 4 _____________________________________ Time: 07:23:53 AM PST US Subject: Re: AeroElectric-List: FW: AeroElectric-List Digest: 9 Msgs - 03/11/09 From: Etienne Phillips 2009/3/12 Emrath > > There are two small > holes for mounting but a 4-40 cross threads in the hole after a turn to 1.5 > turns. I have a garmin GPS-12, which looks pretty similar to your XM antenna. That uses an M3 bolt, so I'm pretty sure they'd try and keep to the same standard. M3 is almost the same as a UNC4-40 anyway. ________________________________ Message 5 _____________________________________ Time: 09:57:21 AM PST US From: "F. Tim Yoder" Subject: Re: AeroElectric-List: FW: AeroElectric-List Digest: 9 Msgs - 03/11/09 I just use a little hook and loop stuff. ( Velcro ) Tim ----- Original Message ----- From: "Emrath" Sent: Thursday, March 12, 2009 6:59 AM Subject: AeroElectric-List: FW: AeroElectric-List Digest: 9 Msgs - 03/11/09 > > I appreciate the replies from David and Bill. Yes this is the XM antenna > and there is no magnet in my version of this antenna. There are two small > holes for mounting but a 4-40 cross threads in the hole after a turn to 1.5 > turns. So what I need must be metric about the same size as a 4-40 in dia. > but with different TPI. I am not concerned with using this is a "buddy's" > plane at this time, but it would not be too hard to modify the mounting > later as I can get to my glare shield underside rather easy to unscrew these > little buggers. > > Marty > > > Time: 01:58:48 PM PST US > From: "Emrath" > Subject: AeroElectric-List: Garmin weather antenna > > > I have a Garmin Weather antenna for my GPSMAP 496 which I would like to > mount on top of my panel. There are two threaded holes in the back of the > antenna to be able to bolt this to the 'dash'. Does anyone know what size > screws are required to do this, I cannot seem to find any reference in my > materials about this. > > Marty > ________________________________ Message 6 > _____________________________________ > > > Time: 02:37:16 PM PST US > From: "David LLoyd" > Subject: Re: AeroElectric-List: Garmin weather antenna > > > Marty, > Do you know if your weather antenna is the model that has the ring magnet on > > the bottom...? > If so, you may not want to mount it to the panel top if you have a compass > near by. > Also, you may not want to permanently mount it in case you want to take the > antenna with you to hook up to another Garmin in a buddy's plane. There is a > procedure for removing the magnet if it is not desired. Some of > us have mounted the antenna high up and out of the way in the front window > frame area using an "L" shaped bracket. The 2 screws holding it can be > quickly removed in the case where you want to use the antenna in another > aircraft. > ......2 cents of comment.... > David > ________________________________ Message 8 > _____________________________________ > > > Time: 07:11:26 PM PST US > From: "Bill Hibbing" > Subject: Re: AeroElectric-List: Garmin weather antenna > > > I have a 396 and if the antenna you're talking about is for the XM weather > I'm pretty sure that the screws are 4-40. What I did to make it easy to > remove the antenna was cut the head off the screw and then sharpen it up a > little. I then drilled holes in the top of the glareshield using the > mounted screws to mark the spot to drill and set the antenna with screws > attached into the holes. I've been using it this way for a couple of years > now and have never had a problem of the antenna coming off the glareshield > in turbulence. Oh yeah, I used as small a drill as possible so that the fit > > was fairly snug. > > Bill > Glasair SIIS-FT > > ________________________________ Message 6 _____________________________________ Time: 05:12:50 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Re: Polyfuses At 07:56 AM 3/12/2009, you wrote: >Sausen)" > > Let me see if I can refresh your memory. Because of the > undocumented crowbar "feature" in the LSE ignitions that came to > light recently, you had suggested using a relay to provide power to > an unprotected wire in the case of a rear mounted battery. Is the crowbar feature for real? Somebody else mentioned that they thought this was a mis-understanding of some variety. You LSE customers should be curious/concerned about this . . . which one is going to call/write LSE and find out? > The concern was that the LSE could cause a trip/blow in an OV > situation however the ignition would be fine and require a > reset. In a rear mounted battery the only way to accommodate this > need to reset was to put a breaker up on the panel but this left an > unprotected line from the battery to the CB. You suggested a > standard relay would be the best way to address this and I didn't > like the additional complexity in addition to replacing one > potential failure mode with another. > It seems to me that a Polyfuse would address the need to reset a > nuisance trip and allow the protection to stay back by the battery > without needing to add relays (more wires, additional failure > points, and additional switches) or big fuses/fat wires to get a CB > up within arm's reach. Okay, I remember. Yeah, the polyfuse looks attractive for this. You might even consider a switch-breaker for the panel mounted control . . . or even just a switch. The wire-protection issue is covered with the polyfuse. Now . . . about that robust mounting. Let me think about this a bit. We could use the same technique for the NTC inrush limiters too. They have the same mounting challenge. I've got to place an order with Digikey tomorrow for some project parts. I'll get both NTC and PTC devices coming and see if we can figure out a way to make these things suitable for the aircraft installation. Bob . . . ________________________________ Message 7 _____________________________________ Time: 06:05:41 PM PST US From: "RV Builder (Michael Sausen)" Subject: RE: AeroElectric-List: Re: Polyfuses The source of the information got it directly from Klaus so I think we can at least assume it's correct for this exercise. I agree on the switch at the panel. I probably won't have a key switch so my intention is to use a normal switch for power control. Thanks for looking into this, let us know if you come up with anything on the mounting. Michael -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Thursday, March 12, 2009 8:11 PM Subject: RE: AeroElectric-List: Re: Polyfuses At 07:56 AM 3/12/2009, you wrote: >Sausen)" > > Let me see if I can refresh your memory. Because of the > undocumented crowbar "feature" in the LSE ignitions that came to > light recently, you had suggested using a relay to provide power to > an unprotected wire in the case of a rear mounted battery. Is the crowbar feature for real? Somebody else mentioned that they thought this was a mis-understanding of some variety. You LSE customers should be curious/concerned about this . . . which one is going to call/write LSE and find out? > The concern was that the LSE could cause a trip/blow in an OV > situation however the ignition would be fine and require a > reset. In a rear mounted battery the only way to accommodate this > need to reset was to put a breaker up on the panel but this left an > unprotected line from the battery to the CB. You suggested a > standard relay would be the best way to address this and I didn't > like the additional complexity in addition to replacing one > potential failure mode with another. > It seems to me that a Polyfuse would address the need to reset a > nuisance trip and allow the protection to stay back by the battery > without needing to add relays (more wires, additional failure > points, and additional switches) or big fuses/fat wires to get a CB > up within arm's reach. Okay, I remember. Yeah, the polyfuse looks attractive for this. You might even consider a switch-breaker for the panel mounted control . . . or even just a switch. The wire-protection issue is covered with the polyfuse. Now . . . about that robust mounting. Let me think about this a bit. We could use the same technique for the NTC inrush limiters too. They have the same mounting challenge. I've got to place an order with Digikey tomorrow for some project parts. I'll get both NTC and PTC devices coming and see if we can figure out a way to make these things suitable for the aircraft installation. 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