---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 09/13/13: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:52 AM - Getting wires into the engine plenum (through the baffles) (donjohnston) 2. 12:10 PM - Re: Over Voltage on Start Up (Robert L. Nuckolls, III) 3. 02:38 PM - Bad Crimp? (Dave Saylor) 4. 04:28 PM - Looking for a circuit that when you press a button powers the device but .... (Jeffrey Skiba) 5. 05:46 PM - Re: Looking for a circuit that when you press a button powers the device but .... (Henador Titzoff) 6. 06:59 PM - Re: Bad Crimp? (nuckollsr) 7. 07:06 PM - Re: Looking for a circuit that when you press a button powers th (nuckollsr) ________________________________ Message 1 _____________________________________ Time: 05:52:44 AM PST US Subject: AeroElectric-List: Getting wires into the engine plenum (through the baffles) From: "donjohnston" What's the best way to get the various sensor wires (fuel press, fuel flow, etc.) from the engine to the firewall? Passing them through a small hole with a grommet seems the easiest. But that would require cutting and re-terminating the wire if sheet metal ever has to come off (not that that's a common task). There's a ton of "pass-through" style connectors, but that adds three new contact points in the line. Just wondering what's... typical. -Don Read this topic online here: http://forums.matronics.com/viewtopic.php?p=408553#408553 ________________________________ Message 2 _____________________________________ Time: 12:10:17 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Over Voltage on Start Up I have 40 hours on my lancair es and have been trying to solve a charging problem since the first startup in july. I have a vertical power electrical system (vp-200), a b&c voltage regulator (lr3c) and an io-550n with a stock 60 amp alternator. Five seconds after engine start vertical power switches power on to the voltage regulator. The alternator comes on and vertical power senses an overvoltage and disconnects the power to the regulator. After resetting the vertical power sometimes two or three times over a 30 second time period the system holds and remains fine for the balance of the flight. I replaced the voltage regulator with an identical replacement with no change. Another clue is that when the system first starts holding in the voltage is on the high side close to 31 volts. There's something fundamentally wrong here. The voltage should NEVER be higher than the regulator's set-point. Readings of 31 volts suggests that the regulator is not getting 'real' bus voltage sample which is critical to proper operation. Attach a (+) lead of a voltmeter to the regulator's bus voltage sense terminal (#3) and the (-) lead to regulator ground terminal (#7). Tell us what you read when the VP screen is reporting 31 volts. It sounds like the regulator 'believes' it's doing a good thing while in fact, the data it's operating on is bogus. How is the regulator grounded? Where does terminal (#3) get it's power? Over time maybe ten minutes it settles down to 28.6 for the remaining flight. I also hear a faint alternator squeal in my headset. I am using two odyssey pc535 12 volt batteries in series and they are at the rear of the plane connected with #2 welding cable This has the 'smell' of a grounding issue where battery recharge currents are polluting the regulator's ground reference causing it to operate at something other than the set-point. Try dismounting the regulator, disconnect existing wire from terminal #7 and run a test wire from #7 to the crankcase. I'm thinking that you may see the ov condition disappear. Can you describe your ground system for us? Bob . . . ________________________________ Message 3 _____________________________________ Time: 02:38:01 PM PST US From: Dave Saylor Subject: AeroElectric-List: Bad Crimp? Bob, Can you tell from the photo if this is this a poor crimp? It was overheating on the back of a strobe switch. I recall Bill Watson had a crimp fail on a strobe switch recently as well. The strobes were occasionally intermittent but the wire near the terminal was always very hot to the touch. The insulation was discolored too. I changed the terminal and the last few inches of wire, and now all is well. Nice and cool. Any comments on the crimp would be much appreciated. Dave Saylor 831-750-0284 CL ________________________________ Message 4 _____________________________________ Time: 04:28:01 PM PST US From: Jeffrey Skiba Subject: AeroElectric-List: Looking for a circuit that when you press a button powers the device but .... Looking for a circuit that when you press a button powers the device but ....if the button is held on it is only powered for a max setting (say 3 seconds) but this same circuit should stop if the button is released before the 3 seconds. Hope that makes sense, I bet it exists already and I just am searching under the wrong name. Thanks in advance for the help Jeff. ________________________________ Message 5 _____________________________________ Time: 05:46:36 PM PST US From: Henador Titzoff Subject: Re: AeroElectric-List: Looking for a circuit that when you press a button powers the device but .... Jeff,=0A=0AI believe you need a better spec.- For example, you say that w hen the button is pressed, the device is powered on.- Then you say if the button is released before the 3 second interval, it should stop powering t he device.- Or at least that's what I think you said.=0A=0AI think you ne ed to divide it into the following functions:=0A=0A* If the button is pr essed for less than N seconds, function 1 happens=0A* If the button is p ressed for more than N seconds, function 2 happens=0A* If the button is held for exactly N seconds, well never mind, there is no such thing unless you have an accuracy spec.- If you do, then function 3 happens.- These three functions need not be mutually exclusive.=0A=0A-=0AWhatever functio nality you want, I believe a microcontroller or CPLD will do the job.- If you describe your functionality more accurately, including output voltage, current, etc., then this group can recommend specific products, including boards.=0A=0A=0AHenador Titzoff=0A=0A=0A________________________________=0A From: Jeffrey Skiba =0ATo: "aeroelectric-list@matronics. com" =0ASent: Friday, September 13, 2013 7:27 PM=0ASubject: AeroElectric-List: Looking for a circuit that when you p ress a button powers the device but ....=0A =0A=0A--> AeroElectric-List me ssage posted by: Jeffrey Skiba =0A=0ALooking for a circui t that when you press a button powers the device but ....if the button is h eld on it is only powered for a max setting (say 3 seconds) but this same c ircuit should stop if the button is released before the 3 seconds.=0A=0AHop e that makes sense, I bet it exists already and I just am searching under t =============== ________________________________ Message 6 _____________________________________ Time: 06:59:33 PM PST US Subject: AeroElectric-List: Re: Bad Crimp? From: "nuckollsr" I think the evidence is pretty conclusive. ANY terminal that gets hot is victim to heat dissipated in some resistance between wire and terminal or terminal and installation surface . . . or both. Compare the appearance of cross section for the terminal you replaces versus a terminal I sectioned for this article: http://tinyurl.com/kfk6jss The terminal you removed was definitely not INTIMATELY mated with the wire strands. There are voids between strands and a large void in the cavity adjacent to captured strands. In the "golden-crush", wires become indistinguishable from the terminal's wire grip barrel. Was the terminal the right size for the wire? If it was installed with a tool from your shop, an investigation is warranted. You don't want to install a bunch of terminals like that! Bob . . . Read this topic online here: http://forums.matronics.com/viewtopic.php?p=408569#408569 Attachments: http://forums.matronics.com//files/photo_135_164.jpg ________________________________ Message 7 _____________________________________ Time: 07:06:37 PM PST US Subject: AeroElectric-List: Re: Looking for a circuit that when you press a button powers th From: "nuckollsr" Henador's suggestion is doable. There's probably a half dozen approaches to this task. Questions: How much current do you need to switch? Can the switch be in the ground side of the load? Do you mind if a relay is used . . . or is it a design goal to be all solid state? You may be able to do this for a few$ of discrete components . . . Bob . . . 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