---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 09/20/07: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:33 AM - dimmer question (Jerry Ricciotti) 2. 03:21 PM - Re: EFIS as only reference??? (Peter Pengilly) 3. 03:25 PM - Re: dimmer question (glaesers) 4. 08:07 PM - Icom A200 Dimmer (Ernest Christley) ________________________________ Message 1 _____________________________________ Time: 07:33:51 AM PST US From: "Jerry Ricciotti" Subject: AeroElectric-List: dimmer question Greetings I am wiring an RV-8 and have two dimmer controls one of which is for back up instruments and a snake/map light. The wire from the back up alt,airspeed and mag compass need to be extended to reach the dimmer control and I want to know if I can connect them all together to one 20awg wire that goes to the dimmer control or should they be extended separately to the dimmer control? (or does it make no difference) Jerry ________________________________ Message 2 _____________________________________ Time: 03:21:33 PM PST US From: "Peter Pengilly" Subject: RE: AeroElectric-List: EFIS as only reference??? I can see that I have not presented my thoughts very well. I am not advocating certified over uncertified, but well designed products. I would be very reticent in holding Blue Mountain up as an example of a well designed system because of their unwillingness to discuss their design and development process - at least when I have asked them. To suggest that Windows is only stable when isolated from other software makes it a completely useless product. The whole point of an operating system is to act as an interface layer between an application (such as a piece of EFIS software) and a host system. Windows is not designed as a real time operating system, sure it can be used as such, but there are better products available - at a price. I don't fly large airplanes for a living, but I do design military aircraft, in particular avionic architectures. I am suggesting that devices that are required to function reliably should be designed (and manufactured) in a demonstrably robust way. One way to show that is to prove to a regulator by jumping through the certification hoops. There are other ways, of course. As there is little service history for most of these devices how can we, prospective customers, make an informed decision as to which one to buy? Its rather difficult in my opinion as most manufacturers don't make enough data available The other option is to install a back-up that does have some kind of provenance. Another EFIS doesn't provide sufficient redundancy for me. Peter -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Terry Watson Sent: 19 September 2007 23:45 Subject: RE: AeroElectric-List: EFIS as only reference??? In general, "Certification" means that at some point the system passed certain set of criteria and the design was frozen at that point. It won't get any better unless something is found to be broken and has to be fixed, otherwise it is a design frozen in time, like a Lycomming 0-360 or a Cessna 172. Sure, they change -but only in ways that won't make them go through certification again. I don't know about most of the great looking new low cost EFIS systems, but I know for certain that my Bluemountain EFIS/one does not use a Windows operating system, and I wouldn't veto a system that did. I have read that Windows is very stable when it is used in a system that is isolated from other software. An EFIS is not constantly being exposed to various other programs, viruses and hackers like a PC is. It is isolated, or used with limited and tested outside software. The downside of most "certified" products is that they are the best that a company could come up with and get through the tests and to market, at some point in the past. If you feel the need for a certified engine, get one, but I don't think your certified Lycoming is any more reliable than my non-certified Superior. If you don't trust non-certified avionics, then pay the price for the tried and tested and blessed, but don't expect to get if for anything like the price of the non-certified, and don't expect to have the advantages of the latest technology. It would seem that many of those who fly big airplanes for a living tend not to trust little airplanes anyway, especially the ones with only one engine and certainly not the ones that don't have dual redundant certified IFR avionics. And if it wasn't built by "certified" A&P's in a "certified" shop, forget about it! Terry RV-8A, Superior, True-Trak, Trio, Bluemountain, Airflow Performance -- all uncertified And none of it flying yet -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Peter Pengilly Sent: Wednesday, September 19, 2007 2:37 PM Subject: RE: AeroElectric-List: EFIS as only reference??? I know because most of it runs on a Windows based operating system, and has not been designed from the start to comply with the relevant standards (if it had Windows would not have been used). There is no way that Windows anything will ever be compatible with a real time safety critical system (because it wasn't designed from the outset for that task). That's not to say it wont work just about all of the time, but do you want to risk your life on it? But that's not the point. The point is that you are taking a risk by using 2 non certified systems to back each other up. Its difficult to quantify that risk without in depth knowledge of how each system was designed & built, and that information is difficult to come by. The fact that Cheltons are so expensive illustrates the issue, very few people on this list could afford one - come to that I suspect not many could afford a Garmin G900! I know that Trutrak makes very good equipment, there are also many other companies that make rather poor stuff and its difficult to tell by looking at the outside. Its not about meeting govt standards, industry standards are just as strict. If it were easy to make a robust system cheaply I suspect Garmin would be offering one, that their cheapest is around $50K (I think) might be a hint as to the scale of the problem. Peter ________________________________ Message 3 _____________________________________ Time: 03:25:01 PM PST US From: "glaesers" Subject: AeroElectric-List: Re: dimmer question Electrically, it makes no difference, as long as the one wire is capable of carrying the current for all 3 lights. Dennis Glaeser --------------------------------------------------------------- Subject: dimmer question From: Jerry Ricciotti Greetings I am wiring an RV-8 and have two dimmer controls one of which is for back up instruments and a snake/map light. The wire from the back up alt,airspeed and mag compass need to be extended to reach the dimmer control and I want to know if I can connect them all together to one 20awg wire that goes to the dimmer control or should they be extended separately to the dimmer control? (or does it make no difference) Jerry ________________________________ Message 4 _____________________________________ Time: 08:07:31 PM PST US From: Ernest Christley Subject: AeroElectric-List: Icom A200 Dimmer It took a little experimentation, but I got it done and thought the information might help someone else. Dimming the backlight of the Icom A200: The installation manual for the Icom A200 indicates a lead to supply +12V for the panel backlight, and another for the backlight's ground. Using an ohmeter, the indicated ground is tied to all the other grounds. The backlight will work without that lead being grounded. At least it did for me. I passed the +12V through an ON-OFF-ON switch and then to a bus controlled by the marker light switch. I tied the two ON contacts of the switch together with a 15 ohm, 1/2 watt resistor. The backlight now comes on with the marker lights (ie, at night), and is full bright with the switch up. With the switch down, current has to pass through the resistor and the backlight is about half as bright. I could have used and ON-ON switch, but I didn't have one on the shelf. This way I have more (albeit, useless) options. 8*) Icom seems to have changed their backlighting scheme over time, but I bought mine only a few weeks ago. As of August 2007, a 15ohm resistor in series with the power supply is sufficient to drop the backlight to half brightness. ------------------------------------------------------------------------------------- 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.