---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 07/30/10: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:12 AM - Re: How to wire a LED to a LR3C (Robert L. Nuckolls, III) 2. 07:27 AM - Re: Re: dual bus, single battery (Robert L. Nuckolls, III) 3. 09:34 AM - New Z-8 drawing (Robert L. Nuckolls, III) 4. 10:56 AM - Re: E-Bus Off/On Indicator Light (D) 5. 11:26 AM - Power Schematic for Review (Gordon Smith) 6. 04:11 PM - Re: New Z-8 drawing (rckol) 7. 08:23 PM - Re: Re: New Z-8 drawing (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 07:12:28 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: How to wire a LED to a LR3C At 12:56 AM 7/30/2010, you wrote: > > >Hi Bob > >I have selected a yellow LED to be used with my 12V LR3C. > >It came from Pep boys wired with a 680 ohm resistor and works quite >well on 12 volts. > >The reason I like it's very bright and doesn't have a flange at the >bottom and is longer than normal which allows me to have it extend a >little bit from panel which can get my attention even though it is >located above my knees because the semiconductor point is in fact in my view. > >Question is since 680 ohms is a bit more resistance that I normally >use to drop 12 volts to run a yellow LED, does your suggestion of >installing two 220 ohm resistors (one in series and one in parallel) >hold true for this LED? Or perhaps up the ohms a little? If the intensity is okay with the as-supplied resistor, just parallel the lamp assembly with sufficiently low resistant to prevent a tiny bit of glow when the LR3 is NOT flashing the light. There's a few milliamps of current flowing in a dark lamp on the LR3's lamp driver output that won't get any light out of a filament but will illuminate an led. You just need to swamp out the effects of this bias current to keep the led dark. Bob . . . ________________________________ Message 2 _____________________________________ Time: 07:27:21 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: dual bus, single battery >I thought I understood all of the heartburn about the AMS switch >after reading the connection and some supplementary articles on the >website... Am I still missing something? Probably not. The design goals behind the Z-figures is to minimize weight, complexity, cost and risk. I.e. the elegant solution. Beyond that, one can make any number of variations to suit personal tastes . . . it's like picking paint colors and upholstery fabric. The only caveat is to be sensitive to increases in risk . . . which may be perfectly acceptable . . . it's your choice. >Keep the thoughts coming, though; I haven't quite convinced myself >that I should let convenience drive my architecture as opposed to >some other factor (like fast load shedding!). Speed in the load shedding activity is not a big design driver. If you finished a cup of coffee with the low voltage light flashing, it probably wouldn't make any difference in the outcome of your flight. Other than smoke in the cockpit or sparks from a radio, no electrical failure is cause for heroic action. My advice to builders over the years is to take a Z-figure (mature and well examined over the years) that most closely meets your needs and then identify shortfalls that my be unique to your needs and desires. If the shortfalls are just matters of preference and do not drive risk to unacceptable levels, why not modify accordingly? What we cannot do as an advisory group is put weight on preferences nor willingness to accept risk. We can't even put numbers on risk. All that can be said about the Z-figures is that they've been pondered and proven over the past 20 years or so and offer comfortable recipes for success. The Z-figures are not the ONLY recipes for success. But a NEW recipe necessarily starts the proofing task over. Bob . . . ________________________________ Message 3 _____________________________________ Time: 09:34:48 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: New Z-8 drawing Discussions with Jon Laury combined with conversation about the abortive Z-13/8 architecture some months ago have prompted a new Z-figure. http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z08A-PRELIMINARY.pdf Design goals include but are not limited to Fuseblock-friendly design (crowbar ov protection replaced with new field disconnect relay system. Two layer electrical system similar to that crafted in Z-13/8. No practical limit to the size of the aux alternator. Anything from the SD-20 on up can be adapted to this architecture. Single battery. This architecture seems well suited to electrically dependent engines where demand for energy exceeds what an SD-8 can supply. The two-layer architecture (as opposed to single-layer like Z-12) offers a way to make the majority of the ship's electrical system completely cold while maintaining engine operations. I'm still pondering the ingredients that might work best in this recipe for success. Thought I would share it with the group. It's a good example of how new and useful things can evolve from a group of folks willing to throw some stuff against the wall to see what sticks! Bob . . . ________________________________ Message 4 _____________________________________ Time: 10:56:37 AM PST US From: D Subject: Re: AeroElectric-List: E-Bus Off/On Indicator Light For what it's worth, I plan to put my nav/strobes (probably of the LED variety) on my E-bus as just such a reminder. Pretty hard to miss the strobes flashing as you give the plane a last look before walking away. Dan ________________________________ Message 5 _____________________________________ Time: 11:26:47 AM PST US From: "Gordon Smith" Subject: AeroElectric-List: Power Schematic for Review I have laid out a preliminary electrical system schematic for an all metal aircraft (Sonex) powered by a Jabiru 3300 engine. I would appreciate Bob's and other lister's comments. I have not yet done a complete Bus Load analysis so some of the wire sizes, fuse sizes and other options could change. I have not included the ignition systems in that they are totally independent of the aircraft electrical system. In considering the possible Z figures, I found that Z20 (small Jabiru) and Z21 (J3300) did not quite offer what I was hoping to accomplish. I believe that Z16 (Rotax 912/914) offered what I would like to have as a basis. Even though we have been cautioned about cherry picking the various Z figures, there are some features in other Z figures that I would like to incorporate. * First, I would like to incorporate the soon to be available AEC9024 device for control of the master contactor, the OV disconnect relay and as a LV warning device. I cherry picked this from Z09 and Z-Laury. I might not have the pin-outs correct, but that can be updated easily at a later time, when the specs are published. I like the idea of a "Breaker-less" panel. * I would like to use the JD101406 Rectifier/Regulator, as in Z09, in place of the Jabiru supplied unit. I understand that this might be a more robust option. * I would like to have the Alternator OV Disconnect Relay to Open one of the Dynamo leads as in Z16 instead of the +B lead as in Z21. * There are two other major options that I would like to consider: 1. BROWNOUT BATTERY WITH B/O RELAY. This as is illustrated in Z10-8. I am considering a MGL EFIS system. They (and others, I believe) offer an option to use a backup battery that is exclusive to powering the EFIS and its accessories. I think that a well designed and crafted E-Bus system makes this exclusive backup unnecessary and redundant. The exclusive backup battery cannot be kept charged unless turned "ON" during operation of the EFIS from the main power source. The Z-10-8 type of backup not only offers a seamless full voltage for ALL E-Bus items, during cranking to start, but adds to the alternator out E-Bus operating time capacity. It will also be topped off and maintained automatically when the main battery is connected to a remote maintainer through the Aux. 12V. Power plug in the panel. 2. E-BUS ALTERNATE FEED RELAY. This as in Z32. In that I have not finalized the calculation of the E-Bus loads, this may or may not be needed. What is the continuous (and intermittent) E-Bus amperage point at which the relay should be implemented? I have incorporated a LED light indicator to show that the E-Bus feed is closed (ON) in any case. The other thing that needs to be reviewed is the use of FUSEABLELINKS. We have also been cautioned to not incorporate them accept in special considerations so please comment: * Fuseablelink in the alternator +B lead at the starter contactor as in Z16, Z18, Z20 and in the alt alternator +B lead to the hot side of the main battery contactor of Z8. * Fuseablelink in the E-Bus alternate feed path at the connection to the E-Bus as in Z13-8 and Z13-8 E-Bus Feeders. * Fuseablelink in the E-Bus alternate feed from the hot side of the battery contactor as in Z16 and Z18. * Fuseablelink at the B/O battery hot lead to the E-Bus alt. feed relay or switch. In this use I could not find illustration in the Z figures. However I think that it might be logical to assume that this use is OK if the use mentioned directly above from the hot side of the main battery is OK. I have attached a four page illustration that shows all options. The first page (D) shows the inclusion of both options. Next (C) and (B) illustrate the two options implemented singly. The last page (A) includes neither option. Gordon Smith ________________________________ Message 6 _____________________________________ Time: 04:11:09 PM PST US Subject: AeroElectric-List: Re: New Z-8 drawing From: "rckol" I might be missing something here, but it seems that unlike the Z13/8, if the battery contactor is open, only the battery bus will be fed by the aux alt (no feed for equipment that might be on a traditional ebus, like minimal pfd, nav and comm). Is this the intent, or do these other functions get piled into the battery bus? -------- rck Read this topic online here: http://forums.matronics.com/viewtopic.php?p=306868#306868 ________________________________ Message 7 _____________________________________ Time: 08:23:59 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: New Z-8 drawing At 06:09 PM 7/30/2010, you wrote: > >I might be missing something here, but it seems that unlike the >Z13/8, if the battery contactor is open, only the battery bus will >be fed by the aux alt (no feed for equipment that might be on a >traditional ebus, like minimal pfd, nav and comm). > >Is this the intent, or do these other functions get piled into the >battery bus? One could add an e-bus to this architecture . . . and in fact, I'll do so at the next iteration. Thanks for bringing it up. I hadn't really got that far yet . . . the e-bus can be added to virtually any architecture. I was fixated on getting the fat wires managed first. 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