---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 12/30/08: 10 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:15 PM - Brass is not a very good conductor (rparigor@SUFFOLK.LIB.NY.US) 2. 12:48 PM - EI Altitude Clock Mod (Don Curry) 3. 01:31 PM - EI SC-5 clock doc error (Ron Shannon) 4. 05:13 PM - Re: EI Altitude Clock Mod (Ed Anderson) 5. 05:33 PM - Re: EI Altitude Clock Mod (currydon@bellsouth.net) 6. 05:33 PM - Re: Brass is not a very good conductor (Vern Little) 7. 05:44 PM - Re: EI SC-5 clock doc error (JAMES BOWEN) 8. 07:14 PM - Thanks for Twisted Pair Answers (Dennis Johnson) 9. 07:36 PM - Re: EI Altitude Clock Mod (S. Ramirez) 10. 07:47 PM - Re: EI SC-5 clock doc error (Greg Young) ________________________________ Message 1 _____________________________________ Time: 12:15:24 PM PST US Subject: AeroElectric-List: Brass is not a very good conductor From: rparigor@SUFFOLK.LIB.NY.US Figured would share with the group at just how poor a conductor brass is. According to: http://www.kp44.org/ftp/ElectricalConductivityOfMaterials.php Brass only has ~ 28% the conductivity of copper. (They don't get as specific as alloy types) I need to somehow wire my port headrest (negative) to my starboard headrest. Shortest distance is direct between headrests but using a traditional wire will be unsightly and make for harder interior install. It needs to carry enough current to allow an occasional jump start. Since Ace hardware sells .032" thick brass 1" wide (alloy 260), I was going to use that and trim it to .75" wide until I researched just how poor a conductor brass is. Could double the thickness and double the width, but that would make for more weight and harder interior install. Anyway, going to use .75" wide by .032" thick copper alloy 110 and glass it in place with one thin layer of 3/4 oz model aeroplane cloth. Ron Parigoris ________________________________ Message 2 _____________________________________ Time: 12:48:19 PM PST US From: "Don Curry" Subject: AeroElectric-List: EI Altitude Clock Mod Ok all you electronics warriors out there, here's a good one: Electronics International designed and markets a pretty nifty-looking aircraft clock called the ASC-5A. One of the nifty things about it is that it is more than just a clock - it's also an altitude alerter. Put in your MDA and your speed-based approach time, and you'll get an LED indication on the face of the instrument telling you that you have arrived either at your altitude or your time. It even has an external-warning capability that, when paired with a tone or voice generator, can send alerts to your headset. But here's the rub: it only has ONE external-warning wire, so regardless of whether it is a timer alert or an altitude alert, it goes out over this one wire (and in the same way, probably as a ground). As a result, when your headset alert sounds on a VOR approach, you must obtain additional input (i.e., you need to look at the face of the clock or your altimeter) to determine whether it is because you have reached the MDA and you need to level off or because you have exhausted your time and need to execute a missed approach. So, internally the unit can differentiate between altitude events and timer events because it lights different LEDs on the face of the instrument for these different events, but EI didn't extend that basic capability to the external-warning feature sticking out the back of the instrument. What were they thinking? At this point, it seems like a simple matter to tap into the light circuits that activate the LEDs on the front of the instrument, extend some wires from those taps out the back, hook up a tone or voice generator, and receive separate signals in your headset for time and altitude alerts. But I don't want to open mine up without first getting some feedback. Ok, I soldered once and it didn't turn out well, so I'm reluctant to tear into my ~$500 instrument without lots of encouragement (I've learned that things that begin with, "Honey, watch this!" often don't turn out well. . .)! Any thoughts? Thanks, Don ________________________________ Message 3 _____________________________________ Time: 01:31:26 PM PST US From: "Ron Shannon" Subject: AeroElectric-List: EI SC-5 clock doc error The previous post inspired me to share this recent discovery. The EI SC-5 clock includes a non-resettable total engine time counter, essentially a Hobbes function. The manual says that in a 12V system, the ORANGE wire should be connected via an N.O. oil pressure switch to provide +12V on closure, when oil pressure develops, which will start the engine timer. This is a little tricky with the B&P oil presure switch, where the N.O. contact is normally grounded -- I even set up a little relay to power the wire that way -- but don't bother. Contrary to the manual, any time the RED +12V main supply wire is hot, the engine timer runs, regardless of what's is or isn't happening on the ORANGE wire. For example, if you're running the panel on ground power, perhaps for training or maintenance, or just entering a flight plan into the GPS before engine start, the engine timer will be ticking up, even though the engine isn't running. (The clock is supposed to be wired to a main bus or e-bus, so it's going to be ON when most anything on the panel is on.) Incidentally, the manual also says that in a 12V system, the BROWN wire should _not_ be connected to anything. After considerable consultation with EI, it was confirmed that the ORANGE wire is at best superfluous to the engine timer function (or any function as far as I could determine) and the BROWN wire is what must be used to control the engine timer. The BROWN wire should be grounded when the engine is OFF, i.e., wired through a N.C. contact on a B&C pressure switch, in parallel with the oil pressure warning light. When the BROWN wire's connection to ground is broken, on engine start, the engine timer begins. So, what the manual says to do doesn't work, and what the manual says not to do is what you have to do to make it work. I suggested to EI that they should at least fix the manual, but they did not indicate any eagerness to do so. Hopefully, this work around will be useful others. Otherwise, it's a nice clock. Ron ________________________________ Message 4 _____________________________________ Time: 05:13:45 PM PST US From: "Ed Anderson" Subject: RE: AeroElectric-List: EI Altitude Clock Mod In electronics all things are possible, Don (well, almost {:>)). The feasibility of doing what you suggest is certainly conceptually simple; however, it depends quite a bit on what format the electronics have taken. If there are isolated wires running from a board to a couple of LED holders then that would probably be fairly simply provided you take care not to overload load the LED circuit. I would put in some sort of isolation barrier - such as an Ops amp - perhaps an Ops amp circuit with a tone generator designed in. However, if the LED's are an integrated part of a printed circuit board - then while still conceptually feasible, you need someone who knows how to modify a board (probably with surface mount components) - a person with the right skills and experience could do it - but, where do you find him? I certainly would hesitate to let just anyone wearing a hat with a lightening bolt through it tackle it. If you can do it without damage to the unit, you might open it up and take a peek. If it looks like wires to the LEDs, then you might consider proceeding further - if it looks like the LED's are an integrated part of a print circuit board, I think I would just button it back up. I agree with you that one would have thought the designer/manufacture would have considered the advantages of a dual audio alarm. Good luck Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.dmack.net/mazda/index.html _____ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Don Curry Sent: Tuesday, December 30, 2008 3:45 PM Subject: AeroElectric-List: EI Altitude Clock Mod Ok all you electronics warriors out there, here's a good one: Electronics International designed and markets a pretty nifty-looking aircraft clock called the ASC-5A. One of the nifty things about it is that it is more than just a clock - it's also an altitude alerter. Put in your MDA and your speed-based approach time, and you'll get an LED indication on the face of the instrument telling you that you have arrived either at your altitude or your time. It even has an external-warning capability that, when paired with a tone or voice generator, can send alerts to your headset. But here's the rub: it only has ONE external-warning wire, so regardless of whether it is a timer alert or an altitude alert, it goes out over this one wire (and in the same way, probably as a ground). As a result, when your headset alert sounds on a VOR approach, you must obtain additional input (i.e., you need to look at the face of the clock or your altimeter) to determine whether it is because you have reached the MDA and you need to level off or because you have exhausted your time and need to execute a missed approach. So, internally the unit can differentiate between altitude events and timer events because it lights different LEDs on the face of the instrument for these different events, but EI didn't extend that basic capability to the external-warning feature sticking out the back of the instrument. What were they thinking? At this point, it seems like a simple matter to tap into the light circuits that activate the LEDs on the front of the instrument, extend some wires from those taps out the back, hook up a tone or voice generator, and receive separate signals in your headset for time and altitude alerts. But I don't want to open mine up without first getting some feedback. Ok, I soldered once and it didn't turn out well, so I'm reluctant to tear into my ~$500 instrument without lots of encouragement (I've learned that things that begin with, "Honey, watch this!" often don't turn out well. . .)! Any thoughts? Thanks, Don __________ Information from ESET NOD32 Antivirus, version of virus signature database 3267 (20080714) __________ The message was checked by ESET NOD32 Antivirus. ________________________________ Message 5 _____________________________________ Time: 05:33:26 PM PST US From: currydon@bellsouth.net Subject: RE: AeroElectric-List: EI Altitude Clock Mod ________________________________ Message 6 _____________________________________ Time: 05:33:31 PM PST US From: "Vern Little" Subject: Re: AeroElectric-List: Brass is not a very good conductor Ron, there has been some discussion on this in the past, and there were questions about sourcing copper bus bar material. Van's Aircraft sells bass strips for this purpose, or you can flatten a copper pipe and use it. I replaced the brass buss-bars on my RV-9A prior to completion after doing a voltage drop analysis through the system. Probably would not make a significant difference, but if you have a choice, use copper. Vern Little Vx Aviation www.vx-aviation.com ----- Original Message ----- From: Sent: Tuesday, December 30, 2008 12:09 PM Subject: AeroElectric-List: Brass is not a very good conductor Figured would share with the group at just how poor a conductor brass is. According to: http://www.kp44.org/ftp/ElectricalConductivityOfMaterials.php Brass only has ~ 28% the conductivity of copper. (They don't get as specific as alloy types) I need to somehow wire my port headrest (negative) to my starboard headrest. Shortest distance is direct between headrests but using a traditional wire will be unsightly and make for harder interior install. It needs to carry enough current to allow an occasional jump start. Since Ace hardware sells .032" thick brass 1" wide (alloy 260), I was going to use that and trim it to .75" wide until I researched just how poor a conductor brass is. Could double the thickness and double the width, but that would make for more weight and harder interior install. Anyway, going to use .75" wide by .032" thick copper alloy 110 and glass it in place with one thin layer of 3/4 oz model aeroplane cloth. Ron Parigoris ________________________________ Message 7 _____________________________________ Time: 05:44:00 PM PST US From: JAMES BOWEN Subject: RE: AeroElectric-List: EI SC-5 clock doc error THANK YOU. I AM INSTALLING THAT SAME CLOCK AS WE SPEAK. MUCH APPRECIATED! JIM BOWEN ectric-list@matronics.comSubject: AeroElectric-List: EI SC-5 clock doc erro rThe previous post inspired me to share this recent discovery.The EI SC-5 c lock includes a non-resettable total engine time counter=2C essentially a H obbes function. The manual says that in a 12V system=2C the ORANGE wire sho uld be connected via an N.O. oil pressure switch to provide +12V on closure =2C when oil pressure develops=2C which will start the engine timer. This i s a little tricky with the B&P oil presure switch=2C where the N.O. contact is normally grounded -- I even set up a little relay to power the wire tha t way -- but don't bother. Contrary to the manual=2C any time the RED +12V main supply wire is hot=2C the engine timer runs=2C regardless of what's is or isn't happening on the ORANGE wire. For example=2C if you're running th e panel on ground power=2C perhaps for training or maintenance=2C or just e ntering a flight plan into the GPS before engine start=2C the engine timer will be ticking up=2C even though the engine isn't running. (The clock is s upposed to be wired to a main bus or e-bus=2C so it's going to be ON when m ost anything on the panel is on.) Incidentally=2C the manual also says that in a 12V system=2C the BROWN wire should _not_ be connected to anything.Af ter considerable consultation with EI=2C it was confirmed that the ORANGE w ire is at best superfluous to the engine timer function (or any function as far as I could determine) and the BROWN wire is what must be used to contr ol the engine timer. The BROWN wire should be grounded when the engine is O FF=2C i.e.=2C wired through a N.C. contact on a B&C pressure switch=2C in p arallel with the oil pressure warning light. When the BROWN wire's connecti on to ground is broken=2C on engine start=2C the engine timer begins.So=2C what the manual says to do doesn't work=2C and what the manual says not to do is what you have to do to make it work. I suggested to EI that they shou ld at least fix the manual=2C but they did not indicate any eagerness to do so. Hopefully=2C this work around will be useful others.Otherwise=2C it's a nice clock.Ron ________________________________ Message 8 _____________________________________ Time: 07:14:21 PM PST US From: "Dennis Johnson" Subject: AeroElectric-List: Thanks for Twisted Pair Answers Thanks to Bob, Simon, and others for your great answers to my question about twisted pair vs. parallel wires. If I keep asking questions and you guys keep giving such well-reasoned answers, some day I might actually understand this stuff. Thanks, Dennis do not archive ________________________________ Message 9 _____________________________________ Time: 07:36:48 PM PST US From: "S. Ramirez" Subject: RE: AeroElectric-List: EI Altitude Clock Mod Don, I looked at the ASC-5A Operating Instructions and saw a picture of its front panel. I am willing to bet that all of those LEDs, the LCD and the switches are connected directly to a printed circuit board. You can verify this for us by opening the unit and looking at it. Obviously, you do this at your own risk. Regardless of whether they are connected by wire or printed circuit board, you can connect to these LEDs by wire. All you have to do is solder wires to the solder points. I'd suggest that you have this done by a person known as an "assembler" in the electronics world. I've seen too many engineers who think they know how to solder, only to destroy a board by applying too much heat, too little heat, too much solder, not cleaning flux off the board, etc. A poor solder job usually results in a failure in our vibration environment. Typically, an LED will be turned on by a driver going low at its cathode. This causes it to sink current through the LED. The LED's anode is connected to the voltage source through a current limiting resistor. When the LED is turned off, the driver will be in the tri-state mode, thus causing only leakage current to flow through the LED. Therefore, when turned on, the LED's cathode will be low, and when turned off, the LED's cathode will be high. What "low" and "high" is depends on the driver and voltage source used. Since a low most likely is the active state (you can verify this), it is not good enough by itself to generate a tone. This means that you will use it as a gating signal to generate such a tone. Someone earlier suggested that you will have to use op amps to isolate these two signals so that they don't interfere with the LEDs' operation. I would suggest keeping it in the digital world and using an appropriate driver that also has a high input impedance. In either case, you are now faced with bringing out one or two ground wire(s) with these two wires and running all wires to wherever you are taking them to, because you will need a reference ground where you are going. I will suggest that you write me directly after you find out what's inside your ASC-5A if you are really serious about this project. There are several details that need to be known to find the best course of action, and only the owner can determine these details. Simon Ramirez Copyright 2008 From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Don Curry Sent: Tuesday, December 30, 2008 3:45 PM Subject: AeroElectric-List: EI Altitude Clock Mod Ok all you electronics warriors out there, here's a good one: Electronics International designed and markets a pretty nifty-looking aircraft clock called the ASC-5A. One of the nifty things about it is that it is more than just a clock - it's also an altitude alerter. Put in your MDA and your speed-based approach time, and you'll get an LED indication on the face of the instrument telling you that you have arrived either at your altitude or your time. It even has an external-warning capability that, when paired with a tone or voice generator, can send alerts to your headset. But here's the rub: it only has ONE external-warning wire, so regardless of whether it is a timer alert or an altitude alert, it goes out over this one wire (and in the same way, probably as a ground). As a result, when your headset alert sounds on a VOR approach, you must obtain additional input (i.e., you need to look at the face of the clock or your altimeter) to determine whether it is because you have reached the MDA and you need to level off or because you have exhausted your time and need to execute a missed approach. So, internally the unit can differentiate between altitude events and timer events because it lights different LEDs on the face of the instrument for these different events, but EI didn't extend that basic capability to the external-warning feature sticking out the back of the instrument. What were they thinking? At this point, it seems like a simple matter to tap into the light circuits that activate the LEDs on the front of the instrument, extend some wires from those taps out the back, hook up a tone or voice generator, and receive separate signals in your headset for time and altitude alerts. But I don't want to open mine up without first getting some feedback. Ok, I soldered once and it didn't turn out well, so I'm reluctant to tear into my ~$500 instrument without lots of encouragement (I've learned that things that begin with, "Honey, watch this!" often don't turn out well. . .)! Any thoughts? Thanks, Don ________________________________ Message 10 ____________________________________ Time: 07:47:52 PM PST US From: "Greg Young" Subject: RE: AeroElectric-List: EI SC-5 clock doc error Same here. I've got one on the bench waiting on a convenient time to install. Good and very timely info. Thanks. Regards, Greg Young _____ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of JAMES BOWEN Sent: Tuesday, December 30, 2008 7:41 PM Subject: RE: AeroElectric-List: EI SC-5 clock doc error THANK YOU. I AM INSTALLING THAT SAME CLOCK AS WE SPEAK. MUCH APPRECIATED! JIM BOWEN _____ From: rshannon@CRUZCOM.COM Subject: AeroElectric-List: EI SC-5 clock doc error The previous post inspired me to share this recent discovery. The EI SC-5 clock includes a non-resettable total engine time counter, essentially a Hobbes function. The manual says that in a 12V system, the ORANGE wire should be connected via an N.O. oil pressure switch to provide +12V on closure, when oil pressure develops, which will start the engine timer. This is a little tricky with the B&P oil presure switch, where the N.O. contact is normally grounded -- I even set up a little relay to power the wire that way -- but don't bother. Contrary to the manual, any time the RED +12V main supply wire is hot, the engine timer runs, regardless of what's is or isn't happening on the ORANGE wire. For example, if you're running the panel on ground power, perhaps for training or maintenance, or just entering a flight plan into the GPS before engine start, the engine timer will be ticking up, even though the engine isn't running. (The clock is supposed to be wired to a main bus or e-bus, so it's going to be ON when most anything on the panel is on.) Incidentally, the manual also says that in a 12V system, the BROWN wire should _not_ be connected to anything. After considerable consultation with EI, it was confirmed that the ORANGE wire is at best superfluous to the engine timer function (or any function as far as I could determine) and the BROWN wire is what must be used to control the engine timer. The BROWN wire should be grounded when the engine is OFF, i.e., wired through a N.C. contact on a B&C pressure switch, in parallel with the oil pressure warning light. When the BROWN wire's connection to ground is broken, on engine start, the engine timer begins. So, what the manual says to do doesn't work, and what the manual says not to do is what you have to do to make it work. I suggested to EI that they should at least fix the manual, but they did not indicate any eagerness to do so. Hopefully, this work around will be useful others. Otherwise, it's a nice clock. Ron ------------------------------------------------------------------------------------- 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.