---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 12/09/03: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:12 AM - SLA battery Problems (Ian) 2. 06:32 AM - Re: SLA battery Problems (Ageless Wings) 3. 06:53 AM - Re: SLA battery Problems (Robert L. Nuckolls, III) 4. 07:02 AM - Voltage Regulators (Boddicker) 5. 07:42 AM - Re: Transponder coax choice (Robert L. Nuckolls, III) 6. 08:15 AM - Re: Voltage Regulators (Robert L. Nuckolls, III) 7. 11:22 AM - Re: Voltage Regulators (Mark Steitle) 8. 03:04 PM - Re: SLA battery Problems (Joel Harding) 9. 03:05 PM - Re: Voltage Regulators (Boddicker) 10. 03:11 PM - Re: Voltage Regulators (Boddicker) 11. 06:59 PM - SD 8 Alternator wiring (hollandm) 12. 07:47 PM - Simple electronics question (Phil Collins) 13. 08:45 PM - Re: RV-List: Cockpit "Audio out" to videocamera (David Carter) 14. 11:19 PM - Re: Simple electronics question (Jerzy Krasinski) ________________________________ Message 1 _____________________________________ Time: 04:12:15 AM PST US From: "Ian " Subject: AeroElectric-List: SLA battery Problems --> AeroElectric-List message posted by: "Ian " Hi all, I have a backup 7AH 12V SLA (sealed Lead acid battery) and it uses a smart charger. It was sitting on the shelf the other day (after charging) and the next morning I found a pool of clear liquid around it? Anyone have any idea what it was? Probably about half a cup. And did not react with bicarb soda. Thanks Ian ________________________________ Message 2 _____________________________________ Time: 06:32:49 AM PST US From: "Ageless Wings" Subject: RE: AeroElectric-List: SLA battery Problems --> AeroElectric-List message posted by: "Ageless Wings" Mornin', Ian... Just a WAG...but was it stored in a cold or cool unheated space just after it was charged? You just said "on the shelf". If so, and it was also very humid, like immediately following rain or snow, it may just be condensation that formed on the side of the warm battery in the cool, damp air. Harley |-----Original Message----- |From: owner-aeroelectric-list-server@matronics.com |[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Ian |Sent: Tuesday, December 09, 2003 7:11 AM |To: aeroelectric-list@matronics.com |Subject: AeroElectric-List: SLA battery Problems | | |--> AeroElectric-List message posted by: "Ian " | | |Hi all, I have a backup 7AH 12V SLA (sealed Lead acid battery) and it |uses a smart charger. | |It was sitting on the shelf the other day (after charging) and the next |morning I found a pool of clear liquid around it? | |Anyone have any idea what it was? | |Probably about half a cup. And did not react with bicarb soda. | |Thanks | |Ian | | | | | | | ________________________________ Message 3 _____________________________________ Time: 06:53:51 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: SLA battery Problems --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 11:10 PM 12/9/2003 +1100, you wrote: >--> AeroElectric-List message posted by: "Ian " > > >Hi all, I have a backup 7AH 12V SLA (sealed Lead acid battery) and it >uses a smart charger. > >It was sitting on the shelf the other day (after charging) and the next >morning I found a pool of clear liquid around it? > >Anyone have any idea what it was? > >Probably about half a cup. And did not react with bicarb soda. SLA batteries have so little liquid within that in no way could the moisture you observed have come from the battery. You can poke a hole in the bottom of all the cells and liquid will not run from the battery. My guess is that it was subjected to a humidity spike and while the air may have been relatively warm, the battery was sitting at or below dew point and the water was condensate. Take 4 ounces of water and pour out onto a flat surface. Compare spread-area of the water with what you observed around your battery. I suspect you'll find that you can generate the same size spread-area with less than an ounce of water. The non-reaction with bicarb was an excellent data point and another strong clue as to the read nature of the phenomenon that produced the water. Bob . . . ________________________________ Message 4 _____________________________________ Time: 07:02:48 AM PST US Subject: AeroElectric-List: Voltage Regulators From: Boddicker --> AeroElectric-List message posted by: Boddicker Bob, I read your book the first time. Highlited the second time. Why do you recomend against internal voltage regulators? How would one remove the internal regulator. Thanks, Kevin ________________________________ Message 5 _____________________________________ Time: 07:42:06 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: Transponder coax choice --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" >Dear Bob: > >I am building a Rans S6S. My avionics include an ICOM transceiver and a >King Mode C transponder. The antennas are about 12 feet from the panel. >Do you think it is OK for me to use RG 58U feed line or should I go to a >lower loss variety? Loss isn't the biggest issue. RG-58 is a WWII veteran that needs to be retired. Its materials and design are of that era (single layer tinned braid, polyethylene inner insulation, PVC outer insulation. Modern coax like RG-400 or RG-142 will have double outer conductor that is silver plated, outer insulation of FEP and inner insulation of PTFE . . . both are modern, high temperature chemical resistant materials. A side benefit is lower loss but superior materials and construction is what you're really looking for. I will invite you to join us on the AeroElectric List to continue this and similar discussions. It's useful to share the information with as many folks as possible. A further benefit can be realized with membership on the list. There are lots of technically capable folks on the list who can offer suggestions too. You can join at . . . http://www.matronics.com/subscribe/ Thanks! Bob . . . -------------------------------------------- ( Knowing about a thing is different than ) ( understanding it. One can know a lot ) ( and still understand nothing. ) ( C.F. Kettering ) -------------------------------------------- ________________________________ Message 6 _____________________________________ Time: 08:15:12 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Voltage Regulators --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 09:07 AM 12/9/2003 -0600, you wrote: >--> AeroElectric-List message posted by: Boddicker > >Bob, >I read your book the first time. >Highlited the second time. >Why do you recomend against internal voltage regulators? >How would one remove the internal regulator. You can leave the regulator in, but add ov protection as shown in figure Z-24 I will invite you to join us on the AeroElectric List to continue this and similar discussions. It's useful to share the information with as many folks as possible. A further benefit can be realized with membership on the list. There are lots of technically capable folks on the list who can offer suggestions too. You can join at . . . http://www.matronics.com/subscribe/ Thanks! Bob . . . -------------------------------------------- ( Knowing about a thing is different than ) ( understanding it. One can know a lot ) ( and still understand nothing. ) ( C.F. Kettering ) -------------------------------------------- ________________________________ Message 7 _____________________________________ Time: 11:22:54 AM PST US From: Mark Steitle Subject: Re: AeroElectric-List: Voltage Regulators --> AeroElectric-List message posted by: Mark Steitle Kevin, What type of alternator are you trying to modify? I converted two ND 55 amp Geo units to external regulator. Mark S. Austin, TX >How would one remove the internal regulator. >Thanks, >Kevin ________________________________ Message 8 _____________________________________ Time: 03:04:44 PM PST US Subject: Re: AeroElectric-List: SLA battery Problems From: Joel Harding --> AeroElectric-List message posted by: Joel Harding Bob, I am using a 17 a h SLA battery to power my panel as I check out my instruments. I hooked an automotive charger with an automatic taper off feature to the battery, and measured charge voltage at over 16 volts, that tapered down to around 14 within just a few minutes. There was no amp reading on the meter, so it was somewhere below 1 amp. I called the distributor but could find no one who could help. Question: Will that voltage damage the battery? Joel Harding ________________________________ Message 9 _____________________________________ Time: 03:05:23 PM PST US Subject: Re: AeroElectric-List: Voltage Regulators From: Boddicker --> AeroElectric-List message posted by: Boddicker on 12/9/03 10:14 AM, Robert L. Nuckolls, III at bob.nuckolls@cox.net wrote: > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > > At 09:07 AM 12/9/2003 -0600, you wrote: >> --> AeroElectric-List message posted by: Boddicker >> >> Bob, >> I read your book the first time. >> Highlited the second time. >> Why do you recomend against internal voltage regulators? >> How would one remove the internal regulator. > > You can leave the regulator in, but add ov protection > as shown in figure Z-24 > > I will invite you to join us on the AeroElectric List > to continue this and similar discussions. > Thanks! > > Bob . . . > I am on the list. That is how I sent this to you. The reason I asked about your recomendation to take out the internal VR, is that it looks to be easier to wire the whole package if I use the LRC3-14. As opposed to the seperate parts listed in Z-24. Just trying to get an idea why you have a distaste for the internal VR. Trying to justify the additional cost. Thanks, Kevin ________________________________ Message 10 ____________________________________ Time: 03:11:45 PM PST US Subject: Re: AeroElectric-List: Voltage Regulators From: Boddicker --> AeroElectric-List message posted by: Boddicker Mark, I think that is what I have. Will need to remove the engine to get the numbers. I have a Tri Q200, Starter, Mags, Alt back in a the whole. Will let you know. Thanks Kevin on 12/9/03 1:22 PM, Mark Steitle at msteitle@mail.utexas.edu wrote: > --> AeroElectric-List message posted by: Mark Steitle > > > Kevin, > What type of alternator are you trying to modify? I converted two ND 55 > amp Geo units to external regulator. > > Mark S. > Austin, TX > > >> How would one remove the internal regulator. >> Thanks, >> Kevin > > > > > > ________________________________ Message 11 ____________________________________ Time: 06:59:53 PM PST US From: "hollandm" Subject: AeroElectric-List: SD 8 Alternator wiring --> AeroElectric-List message posted by: "hollandm" I'm installing a Vans 60amp internally regulated alternator with a B&C SD8 as a backup. The printed insert sent with the B&C indicate that a over voltage protection isn't necessary with this type of alternator since "regenerative over-voltage failures are not possible". If this is true then there would appear to be a contradiction with DWG 504-500, also from B&C which shows a crowbar OVM in this system along with S8005-1. My question: Other than the PMR1 regulator and filter capacitor is there any specific reason to add OVM protection to the SD8, as a standby alternator? Thanks ________________________________ Message 12 ____________________________________ Time: 07:47:55 PM PST US From: "Phil Collins" Subject: AeroElectric-List: Simple electronics question --> AeroElectric-List message posted by: "Phil Collins" I have what I think is a simple electronics question, but being an electronics simpleton I don't have the simple answer. Any suggestions or direction for further study would be appreciated. I want to use National Semiconductor LM34 temperature sensor to create an OAT display in my cockpit. So far I've hooked up the sensor and tested it in the freezer, in front of a Halogen light and in ice water and have recorded temps on my OAT display of +5 to +165F. The temp readings seem accurate. The sensor is a three wire package that hooks to ground, power (Vs) +5 to +20 VDC and to the display. It puts out 10mv per degree fahrenheit with a current draw of 90mA... so far so good. In order to get readings in the below zero fahrenheit range the sensor output lead must be connected via a resistor to -Vs with a current flow of approx 20mA. I'm in search of -Vs, and my novice mind is stuck. From my high school ohms law, it would seem that I could create a circuit containing two 50 ohm resistors in series with a voltage drop of 7 volts across each, then use the center connection as "ground" for the purpose of the sensor and call the other two terminals +7 and -7VDC. (I haven't tried to size the resistor tieing the sensor lead to -Vs (or in this case -7VDC)) Even with the little I know, it seems that this circuit would be wasteful and there should be a more effective way to power the simple OAT sensor. Should I be looking at voltage regulator chips, a full power supply, or should I just do the resistor thing, wrap it all with shrink wrap and never speak of the inefficiencies lurking in the OAT circuit? I'm sure by now, I've exposed my total ignorance on the subject, so I'll close and hope for guidance or reading suggestions from wiser minds. Thanks, Phil ________________________________ Message 13 ____________________________________ Time: 08:45:12 PM PST US From: "David Carter" Subject: AeroElectric-List: Re: RV-List: Cockpit "Audio out" to videocamera --> AeroElectric-List message posted by: "David Carter" I bought the "attenuating audio cable" as suggested and it worked fine Saturday. "Thanks" to all on both lists for the excellent suggestions. This one seems to be the easiest to implement and best value. If I'd had a small mick to put in earcup, that would have also been a "top pick". David ----- Original Message ----- From: "James E. Clark" Subject: RE: RV-List: Cockpit "Audio out" to videocamera > --> RV-List message posted by: "James E. Clark" > > Try ... > > > 42-2152 > > 6.5' Attenuating Dubbing Cord > > $3.99 > ... FEATURES: Connects earphone jack from radio, cassette or CD to > recorder's input or mic jack 1/8" phone plug on both ends Length > 6-1/2-feet > > Radio Shack > 42-2152 > > > James > > > > -----Original Message----- > > From: owner-rv-list-server@matronics.com > > [mailto:owner-rv-list-server@matronics.com]On Behalf Of David Carter > > Sent: Thursday, December 04, 2003 5:33 PM > > To: RV-list; aeroelectric-list > > Subject: RV-List: Cockpit "Audio out" to videocamera > > > > > > --> RV-List message posted by: "David Carter" > > > > > >[SNIP] > > > > > When I replay cockpit recordings, the audio of the video camera is > > distorted - amplitude too high coming out of intercom to be > > compatible with > > video recorder. > > Appreciate any tips. > > > > David Carter ________________________________ Message 14 ____________________________________ Time: 11:19:50 PM PST US From: Jerzy Krasinski Subject: Re: AeroElectric-List: Simple electronics question --> AeroElectric-List message posted by: Jerzy Krasinski Phil Collins wrote: >--> AeroElectric-List message posted by: "Phil Collins" > > >I have what I think is a simple electronics question, but being an >electronics simpleton I don't have the simple answer. Any suggestions >or direction for further study would be appreciated. > >I want to use National Semiconductor LM34 temperature sensor to create >an OAT display in my cockpit. So far I've hooked up the sensor and >tested it in the freezer, in front of a Halogen light and in ice water >and have recorded temps on my OAT display of +5 to +165F. The temp >readings seem accurate. > >The sensor is a three wire package that hooks to ground, power (Vs) +5 >to +20 VDC and to the display. It puts out 10mv per degree fahrenheit >with a current draw of 90mA... so far so good. > >In order to get readings in the below zero fahrenheit range the sensor >output lead must be connected via a resistor to -Vs with a current flow >of approx 20mA. I'm in search of -Vs, and my novice mind is stuck. >>From my high school ohms law, it would seem that I could create a >circuit containing two 50 ohm resistors in series with a voltage drop of >7 volts across each, then use the center connection as "ground" for the >purpose of the sensor and call the other two terminals +7 and -7VDC. (I >haven't tried to size the resistor tieing the sensor lead to -Vs (or in >this case -7VDC)) > >Even with the little I know, it seems that this circuit would be >wasteful and there should be a more effective way to power the simple >OAT sensor. Should I be looking at voltage regulator chips, a full power >supply, or should I just do the resistor thing, wrap it all with shrink >wrap and never speak of the inefficiencies lurking in the OAT circuit? >I'm sure by now, I've exposed my total ignorance on the subject, so I'll >close and hope for guidance or reading suggestions from wiser minds. > >Thanks, >Phil > Phil, Something must be wrong there. It is hard to believe that this circuit draws 90mA, they typically take very little current, a small fraction of milliamper with no load, and the maximum current allowed to draw from them is only several mA . At such currents it does not make sense to call the circuit "wastefull", unless you plan to use a tiny watch battery as a power source. Could you please check the current and connections again? What meter do you use on the output i.e. what is its internal resistance? Maybe you overload the circuit with a low resistance meter. Does the sensor get hot? At 90 mA and 5V supply voltage you would be generayting almost 1/2 watt in the tiny sensor, and that should make it quite hot. Jerzy > > > > >