---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 09/17/12: 12 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:18 PM - Re: Why multiple skinny power wires? (Robert L. Nuckolls, III) 2. 02:32 PM - Kitplanes Editorial Policy (Paul Millner) 3. 02:32 PM - The biggest lie of Campaign 2012 (RScott) 4. 02:51 PM - Re: The biggest lie of Campaign 2012 TIME FOR THE DELETE BUTTON -- AGAIN!! (John Grosse) 5. 03:19 PM - Re: The biggest lie of Campaign 2012 TIME FOR THE DELETE BUTTON -- AGAIN!! (John Loram) 6. 03:28 PM - Blow or suck (on a heat sink)? (rparigoris) 7. 05:33 PM - Re: USB power (Eric Page) 8. 05:47 PM - Re: Blow or suck (on a heat sink)? (Eric M. Jones) 9. 06:14 PM - Re: Blow or suck (on a heat sink)? (R. curtis) 10. 08:34 PM - Re: Blow or suck (on a heat sink)? (Richard E. Tasker) 11. 08:34 PM - Re: Blow or suck (on a heat sink)? (Robert L. Nuckolls, III) 12. 08:40 PM - Re: USB power (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 12:18:52 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Why multiple skinny power wires? At 04:53 PM 9/16/2012, you wrote: Those are multiple wires to multiple pins, not multiple wires to the SAME pin as in the original post from the SkyRadar installer. Yes, the original thread was discussing twin ground and twin power wires to a single function device. The 430 specifies a 10A CB on the com and a 5A CB for the Nav. I suppose they could have used one 15A circuit, but that would require larger wire that wouldn't fit in the connector pins. That makes sense. When you have lots of capability built into a single box, it should be expected that some features be powered separately from each other. In this case we might see multiple paralleled ground wires but multiple, independent power feeders. There is no common convention for these decisions. When in doubt, do what the manufacturer's instructions call out. The 430 does this with nav and comm functions. Not sure why you would ever want only one of functions but the option is there. Not so much for WANTING only one at a time but a deliberate isolation such that failure of one system doesn't pop the protection and take down multiple systems. Bob . . . ________________________________ Message 2 _____________________________________ Time: 02:32:27 PM PST US From: Paul Millner Subject: AeroElectric-List: Kitplanes Editorial Policy On 9/16/2012 6:31 AM, Eric M. Jones wrote: > The attached was rewritten for Kitplanes, but they rejected it perfunctorily. My writing is intentionally a bit edgey--as any reader of this blog will tell you. Eric, Kitplanes published my stuff, and I'm edgy too! :-) Paul -- Please note my new email address! millner@me.com ________________________________ Message 3 _____________________________________ Time: 02:32:48 PM PST US From: RScott Subject: AeroElectric-List: The biggest lie of Campaign 2012 We knew that idiot Obama's budget was bogus from the beginning, but it's even worse! The article doesn't get to the important stuff for several paragraphs. http://www.lvrj.com/opinion/the-biggest-lie-of-campaign-2012-169941296.html ________________________________ Message 4 _____________________________________ Time: 02:51:43 PM PST US From: John Grosse Subject: Re: AeroElectric-List: The biggest lie of Campaign 2012 TIME FOR THE DELETE BUTTON -- AGAIN!! Why do you feel you have to pollute this list with off topic BS? John Grosse > RScott > September 17, 2012 4:31 PM > > > We knew that idiot Obama's budget was bogus from the beginning, but > it's even worse! The article doesn't get to the important stuff for > several paragraphs. > > http://www.lvrj.com/opinion/the-biggest-lie-of-campaign-2012-169941296.html > > ________________________________ Message 5 _____________________________________ Time: 03:19:52 PM PST US From: "John Loram" Subject: RE: AeroElectric-List: The biggest lie of Campaign 2012 TIME FOR THE DELETE BUTTON -- AGAIN!! John: the spam appears to have been sent from 'Off List'. The aerolectric return address was bogus. The sender appears to have harvested the list addresses and is long gone. -john- > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On > Behalf Of John Grosse > Sent: Monday, September 17, 2012 2:51 PM > To: aeroelectric-list@matronics.com > Subject: Re: AeroElectric-List: The biggest lie of Campaign > 2012 TIME FOR THE DELETE BUTTON -- AGAIN!! > > --> > > Why do you feel you have to pollute this list with off topic BS? > > John Grosse > > RScott September 17, 2012 4:31 PM > > > > > > We knew that idiot Obama's budget was bogus from the beginning, but > > it's even worse! The article doesn't get to the important > stuff for > > several paragraphs. > > > > > http://www.lvrj.com/opinion/the-biggest-lie-of-campaign-2012-169941296 > > .html > > > > > > > > > > > > > > Photoshare, and much much more: > > > > ________________________________ Message 6 _____________________________________ Time: 03:28:22 PM PST US Subject: AeroElectric-List: Blow or suck (on a heat sink)? From: "rparigoris" Hi group I decided I'm an idiot when it comes to refrigeration. I made a slick carry tote for a 12 volt 9 pound battery, with holder for the jumper cables and a super powerful flashlight. I will share pics once I complete the project. During the summer I ruined my 35MM digital camera by leaving it in a "very" hot car. I asked my EE build partner when we got the camera and he assured me, no problem, heat will not kill it. OK now to my question. I figured I would make an insulated compartment on my carry tote to put my camera in and use a piezo cooler to keep it at less than "nonpassive failure" temperature. My EE build partner gave me a Peltier made for a CPU chip. I fooled with it and was happy enough feeling the cold to install it. What a failure. I could easily "raise" the inside temperature by 15 degrees, and after a lot of fooling was able to get my cooler to only raise the temperature 2 degrees F over ambient. Going forward and using the mentality to never let a mechanical or electrical device get the better of you, I bought a do it yourself refrigeration kit off of E-Bay. BTW the compartment is now large enough for 2 soda cans or the new camera, and I figure for camera ops, I may be able to electrically series the two Peltier device inputs to lower the power drain (will try it and report). Side note I never knew that you can series stack Peltier devices together in series (hot to cold) to increase both heating and cooling. Sorry for the rambling, my question: I purchased this kit: http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=180885684793&ssPageName=ADME:L:OU:US:3160 No instructions. On the hot side heat sink, do I want to blow or suck with the fan? On the cold side heat sink, do I want to blow or suck with the fan? Thanking you in advance. Ron Parigoris Read this topic online here: http://forums.matronics.com/viewtopic.php?p=383343#383343 ________________________________ Message 7 _____________________________________ Time: 05:33:02 PM PST US Subject: Re: AeroElectric-List: USB power From: Eric Page John, please be aware that simply installing a USB receptacle and placing 5V across pins 1 and 4 will not charge an Apple iPad (or iPhone, or Samsung Galaxy Tab, and probably others) as you might expect. The USB standard only requires 500mA (one-half ampere) be available from a USB receptacle, and that's what you'll get from a computer's USB port and from many 110VAC and 12VDC USB adapters. That's sufficient for many phones, but smart-phones and tablets with large batteries require larger currents to charge properly. That's not the only problem. Both Apple and Samsung have ignored the USB standards to make proprietary charging schemes. Their devices look for voltages on the data pins, D- and D+, to indicate that the charger is able to supply their relatively high current demands. If your solution doesn't provide this, your tablet will assume it's plugged into a standard 500mA source. At best it will charge at a trickle, and may refuse to charge at all (Galaxy Tabs are famous for the "red X" indicating not charging). Apple's scheme uses three different variations of data pin voltages to designate three levels of charger current delivery capability: 500mA, 1,000mA and 2,000mA. iPhones require 1,000mA to quick-charge and iPads require 2,000mA. Also note that Apple products are notoriously fussy about charge voltage falling between 5V and 5.5V. Any less than 5V and they begin to ramp down their current draw, and therefore their charge rate. Many cheap USB adapters are very poorly regulated and will suffer voltage dropout as current demand rises. Furthermore, a switching regulator that's built to a price will likely omit properly selected filtering elements and may inject noise into other components sharing the same voltage source. For example, I have an iPhone car charger (made overseas; you can guess where) that makes my car's AM radio receiver unlistenable! So, a properly designed regulator with low voltage dropout, sufficient current overhead, and properly designed input and output filtering is important both for proper charging performance and to avoid noise in other aircraft systems. Having said all of that, it's not rocket science! Here's what your USB receptacle needs to provide to properly quick-charge your iPad (for iPhones, reverse pins 2 and 3): Pin 1 (+V): 5V (no less; ideally ~5.2V) Pin 2 (D-): 2.00V Pin 3 (D+): 2.75V Pin 4: Ground Assuming you start with a good supply, the data pin voltages are easy to accomplish with a resistor voltage divider. Small 1/8-watt resistors are perfectly adequate as there's negligible current flow from these two pins; they're just signaling voltages. See http://bit.ly/8JLUUe for a diagram of a resistor voltage divider and a calculator to figure resistor values. Try to keep R1 at 10000 ohms or more, as this will ensure very little current flow to ground. Cheers, Eric P.S. I hope I'm safe mentioning this here, since I have nothing yet to sell, but I hope to bring what I think will be an elegant solution to this problem to market in the near future. Initial design has a panel-mounted single or dual-USB receptacle that occupies ~1 sq in of panel space and less than 2 in of depth, with a very small and light remote-mounted voltage source capable of simultaneously fast-charging two tablets or a tablet and a smart-phone. If you're interested, send me an email at VersoElectronics(at)cox(dot)net and I'll get in touch only if/when I finalize the design. ________________________________ Message 8 _____________________________________ Time: 05:47:10 PM PST US Subject: AeroElectric-List: Re: Blow or suck (on a heat sink)? From: "Eric M. Jones" Ron, See: http://www.target.com/p/wagan-thermo-fridge-warmer-6-l/-/A-10577497 So cheap you can't afford to make one. -------- 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=383369#383369 ________________________________ Message 9 _____________________________________ Time: 06:14:15 PM PST US From: "R. curtis" Subject: Re: AeroElectric-List: Blow or suck (on a heat sink)? > No instructions. On the hot side heat sink, do I want to blow or suck with > the fan? On the cold side heat sink, do I want to blow or suck with the > fan? > Ron Parigoris It is almost always better to "Suck than to blow". For either a heating or cooling application. If you are directing a fan to blow on a heat sink, a larger quantity at a higher velocity makes contact with the sink and more of the heat is transferred. On the "Suck" side of the fan the air moves in from a wider area and is not as effective unless you specifically design a shroud to direct the airflow across the sink. Roger ________________________________ Message 10 ____________________________________ Time: 08:34:18 PM PST US From: "Richard E. Tasker" Subject: Re: AeroElectric-List: Blow or suck (on a heat sink)? Your description is fine, but the first sentence is opposite of the description. I think you meant to write "better to blow than suck" Dick Tasker R. curtis wrote: > >> No instructions. On the hot side heat sink, do I want to blow or suck with the fan? On the cold side heat sink, do I want to blow or suck with the fan? >> Ron Parigoris > > It is almost always better to "Suck than to blow". For either a heating or cooling application. If you are directing a fan to blow on a heat sink, a larger quantity at a higher velocity makes > contact with the sink and more of the heat is transferred. On the "Suck" side of the fan the air moves in from a wider area and is not as effective unless you specifically design a shroud to direct > the airflow across the sink. > > Roger > > -- Please Note: No trees were destroyed in the sending of this message. We do concede, however, that a significant number of electrons may have been temporarily inconvenienced. -- ________________________________ Message 11 ____________________________________ Time: 08:34:20 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Blow or suck (on a heat sink)? At 05:27 PM 9/17/2012, you wrote: > > >Hi group > >I decided I'm an idiot when it comes to refrigeration. > >I made a slick carry tote for a 12 volt 9 pound battery, with holder >for the jumper cables and a super powerful flashlight. I will share >pics once I complete the project. > >During the summer I ruined my 35MM digital camera by leaving it in a >"very" hot car. I asked my EE build partner when we got the camera >and he assured me, no problem, heat will not kill it. > >OK now to my question. I figured I would make an insulated >compartment on my carry tote to put my camera in and use a piezo >cooler to keep it at less than "nonpassive failure" temperature. My >EE build partner gave me a Peltier made for a CPU chip. I fooled >with it and was happy enough feeling the cold to install it. What a >failure. I could easily "raise" the inside temperature by 15 >degrees, and after a lot of fooling was able to get my cooler to >only raise the temperature 2 degrees F over ambient. > >Going forward and using the mentality to never let a mechanical or >electrical device get the better of you, I bought a do it yourself >refrigeration kit off of E-Bay. BTW the compartment is now large >enough for 2 soda cans or the new camera, and I figure for camera >ops, I may be able to electrically series the two Peltier device >inputs to lower the power drain (will try it and report). Side note >I never knew that you can series stack Peltier devices together in >series (hot to cold) to increase both heating and cooling. > >Sorry for the rambling, my question: >I purchased this kit: >http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=180885684793&ssPageName=ADME:L:OU:US:3160 > >No instructions. On the hot side heat sink, do I want to blow or >suck with the fan? On the cold side heat sink, do I want to blow or >suck with the fan? Doesn't matter . . . it's MOVEMENT of air over the warmer/cooler surface that greatly improves the rate of transfer for thermal energy. Suggest you review the technical data for TEC parts at: http://tinyurl.com/9fcv9l4 Particularly the instructions and tutorials. You might wish to consider some form of temperature control for the protected space. It may be that the best choice for protecting the camera will not secure a pleasantly cooled can of pop. If you keep the camera too cold (below dew point for surrounding atmosphere) there is risk of condensing moisture on the camera's inner workings when brought out into the warmer, moist air. Also, these critters are sorta cool but they consume significant amounts of energy. Do a load analysis after satisfactory protection is achieved . . . then see how long you can let your vehicle battery support his load and still get the engine started. This will put DEEP cycles on the vehicle battery and reduce its service life considerably. Passive protection might be more practical. Store the camera in one of those zippered-lid insulated carry cases (about a six pack size) along with those reusable ice bags (not frozen). You're taking advantage of the container insulation and relative thermal mass of the freezing medium to maintain the camera at day-long-average temperature which will be many degrees cooler than worst case. Bob . . . ________________________________ Message 12 ____________________________________ Time: 08:40:53 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: USB power At 07:31 PM 9/17/2012, you wrote: > >John, please be aware that simply installing a USB receptacle and >placing 5V across pins 1 and 4 will not charge an Apple iPad (or >iPhone, or Samsung Galaxy Tab, and probably others) as you might expect. > >The USB standard only requires 500mA (one-half ampere) be available >from a USB receptacle, and that's what you'll get from a computer's >USB port and from many 110VAC and 12VDC USB adapters. That's >sufficient for many phones, but smart-phones and tablets with large >batteries require larger currents to charge properly. > >That's not the only problem. Both Apple and Samsung have ignored >the USB standards to make proprietary charging schemes. Their >devices look for voltages on the data pins, D- and D+, to indicate >that the charger is able to supply their relatively high current >demands. If your solution doesn't provide this, your tablet will >assume it's plugged into a standard 500mA source. At best it will >charge at a trickle, and may refuse to charge at all (Galaxy Tabs >are famous for the "red X" indicating not charging). > >Apple's scheme uses three different variations of data pin voltages >to designate three levels of charger current delivery capability: >500mA, 1,000mA and 2,000mA. iPhones require 1,000mA to quick-charge >and iPads require 2,000mA. > >Also note that Apple products are notoriously fussy about charge >voltage falling between 5V and 5.5V. Any less than 5V and they >begin to ramp down their current draw, and therefore their charge >rate. Many cheap USB adapters are very poorly regulated and will >suffer voltage dropout as current demand rises. Furthermore, a >switching regulator that's built to a price will likely omit >properly selected filtering elements and may inject noise into other >components sharing the same voltage source. For example, I have an >iPhone car charger (made overseas; you can guess where) that makes >my car's AM radio receiver unlistenable! > >So, a properly designed regulator with low voltage dropout, >sufficient current overhead, and properly designed input and output >filtering is important both for proper charging performance and to >avoid noise in other aircraft systems. > >Having said all of that, it's not rocket science! Here's what your >USB receptacle needs to provide to properly quick-charge your iPad >(for iPhones, reverse pins 2 and 3): > >Pin 1 (+V): 5V (no less; ideally ~5.2V) >Pin 2 (D-): 2.00V >Pin 3 (D+): 2.75V >Pin 4: Ground > >Assuming you start with a good supply, the data pin voltages are >easy to accomplish with a resistor voltage divider. Small 1/8-watt >resistors are perfectly adequate as there's negligible current flow >from these two pins; they're just signaling voltages. See >http://bit.ly/8JLUUe for a diagram of a resistor voltage divider and >a calculator to figure resistor values. Try to keep R1 at 10000 >ohms or more, as this will ensure very little current flow to ground. > >Cheers, Eric > >P.S. I hope I'm safe mentioning this here, since I have nothing yet >to sell, but I hope to bring what I think will be an elegant >solution to this problem to market in the near future. Initial >design has a panel-mounted single or dual-USB receptacle that >occupies ~1 sq in of panel space and less than 2 in of depth, with a >very small and light remote-mounted voltage source capable of >simultaneously fast-charging two tablets or a tablet and a >smart-phone. If you're interested, send me an email at >VersoElectronics(at)cox(dot)net and I'll get in touch only if/when >I finalize the design. Good and useful data Eric. Thanks! Your product sounds like it would have some appeal to OBAM aircraft owners so advertising availability here on the List is welcome also. 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