---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 10/29/11: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:28 AM - Re: ZTRON LABS ZL-BP4/8 (Robert L. Nuckolls, III) 2. 08:02 AM - Re: Fw: new stuff (Robert L. Nuckolls, III) 3. 08:26 AM - Re: ZTRON LABS ZL-BP4/8 (user9253) 4. 08:28 AM - RG Batteries: I learned something last night (Robert L. Nuckolls, III) 5. 09:10 AM - Re: new stuff (Eric M. Jones) 6. 05:04 PM - Re: Re: Canopy Switch (B Tomm) ________________________________ Message 1 _____________________________________ Time: 07:28:33 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: ZTRON LABS ZL-BP4/8 At 04:30 PM 10/28/2011, you wrote: > >10/28/2011 > >Hello Bob Nuckolls, I am interested in your reaction to this product: > >http://www.ztronlabs.com/products/bp8/brochure.pdf I have no doubt that they perform as advertised. But unlike the legacy breaker/ fuse + switch combinations, the features give rise to new questions. First, what deficiencies in the design, installation, maintenance and cost of ownership for breaker/fuse+switch are eliminated or at least mitigated by the new product? In other words, are there demonstrable, compelling performance gains for adopting this product? Are they more reliable? In other words, has history offered cases where the B/F+S combination has failed to perform it's intended task? Are the new devices less likely to repeat any such events assuming they exist? Their parts-count is higher . . . and certainly part vulnerable to external stimulus for which DO-160 was crafted to explore. If not a reliability trade-off, then are they less expensive to own, operate and service? $190 for eight controlled positions works out to nearly $25 per position. Certainly competitive with B+S but not with F+S configurations. Convenience? Hmmm . . . you cut a big hole in the panel to mount a big electro- whizzy that shares form, fit and function with no other product like it. Suppose you only need 6 of the positions . . . or need 9? These controls do not offer the flexibility of multi-function toggles with spring loading and progressive transfers. Unlike the toggle with immediately recognizable position, these devices use lights. Are they sunlight viewable? This device is not a drop-in replacement for all protected and controlled circuits in the airplane . . so your almost sure to have alternative hardware tucked away on the panel anyhow. Then there is the question as to how well the designers understand the legacy aircraft environment. Maybe they didn't do DO-160 verification but were they cognizant of the design tools and processes that go to passing a DO-160 verification? Everyone needs to make up their own mind as to what features of reliability, convenience, cost and STYLE goes to meeting personal design goals on their project. I'll suggest that there are few technical and even fewer economic incentives for adapting such a product to an OBAM aircraft. But when it comes to style, there's no accounting for taste. Bob . . . ________________________________ Message 2 _____________________________________ Time: 08:02:18 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Fw: new stuff At 06:52 PM 10/28/2011, you wrote: >Has anyone looked into these? Could they achieve a gas tight connection? Sure. Look at the list of patents at the bottom of the home page. You can browse these at freepatentsonline.com These are the real deal. But they are not simple nor will they be cheap. Probably quite attractive to conducting some field repair/modification task but certainly not cost or space effective in the production environment. Bob . . . ________________________________ Message 3 _____________________________________ Time: 08:26:22 AM PST US Subject: AeroElectric-List: Re: ZTRON LABS ZL-BP4/8 From: "user9253" A fuse holder costs much less and models are available to hold up to 20 fuses. http://www.amazon.com/Bussman-holder-Truck-electrical-application/dp/B0026BK6GY/ref=sr_1_10?ie=UTF8&qid=1313369427&sr=8-10 I have had trouble operating capacitance type switches when my fingers are cold and dry or when wearing gloves. If one of those 8 switches goes bad, the whole unit will have to be removed for repair or replacement. If the company goes out of business, it will be a challenge to fill the hole in the panel with some type of replacement. An aircraft builder has the skills to replace a fuse or switch, but might not be able to repair electronic switches. There are nice looking discrete illuminated switches available. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=356263#356263 ________________________________ Message 4 _____________________________________ Time: 08:28:41 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: RG Batteries: I learned something last night That bench test battery I featured in a posting a few days ago had not be cap-checked in several years. The thing is over ten years old and has yielded a great return on investment. I did a load test on this battery about a week ago. It dumped about 300A for 15 seconds at the 70F mark on the load meter. A value that is less than 1/2 the as-new capability. Just for grins, I pulled out the CBAII battery tester. The bench battery had been on a maintainer for a couple days. I did a 6A discharge test. The value I use as exemplary of most of my instrumentation experiments. The battery delivered 24+ a.h. of useful energy! Going to the factory data on this battery we see: http://www.aeroelectric.com/Pictures/Curves/33AH_12V_Capacity_vs_Load.gif The factory says a 6.6A load will deplete this battery in about 4 hours . . . or 24+ a.h. In years past, my teachers modeled the battery as a large array of cells connected in a series-parallel configuration with EACH cell offering some finite energy value combined with it's own source impedance. If you loose 1/2 the cell in the full-up array, energy drops by 1/2 but source impedance doubles. This experiment last night showed that while the source impedance for the battery had doubled (1/2 the cranking snort), the total energy available was still almost as-new! This means that the gazillion itty-bitty cell analogy is not quite accurate. Those cells can experience a rise in source impedance while still offering their original energy capability. This battery as-new will deliver 9V at over 800A for 15 seconds. This suggests a source impedance of (12-9)/800 = .004 ohms. It now produces about 300A so the new source impedance is (12-9)/300 = .010 ohms. So while the impedance has doubled, the available energy at 6A loading has been barely affected . . . if at all. A rise from .004 to .010 ohms source impedance has little influence on a test load of (12/6)= 2 Ohms. This argues with any analogy that suggests a "dead" micro-cell in a battery becomes totally disconnected from the array. It suggests that individual cells can demonstrate an ability to store and regurgitate energy while experiencing an independent and unrelated rise in source impedance. This discovery suggests that it is possible for a battery to meet battery-only-ops requirements while demonstrating reduced cranking performance. This ol' dog is still learning . . . and my grey haired bench test battery is still in service. Bob . . . ________________________________ Message 5 _____________________________________ Time: 09:10:19 AM PST US Subject: AeroElectric-List: Re: new stuff From: "Eric M. Jones" I like some of the accessory connectors like the auto-fuse adapter. They look nice, but for semi-reusable, manually applied connectors, can they really be better than a regular wirenut? Wirenuts have fallen out of fashion, but they are extremely reliable and have their own strain relief. Some come pre-gooped for water-tightness. I have been looking into replacing my products' Fastons and crimp terminals with cage clamps and am especially interested in the lever-operated cage clamps. Ultra-reliable and simple to use. In this post-fiberoptic world, maybe NO connectors are the best way to go for data. Vehicles just put data on the powerlines, and various wireless protocols are taking the place of a whole lot of wire in advanced designs. Hey, NO connectors! Would you trust your elevator trim to Bluetooth or Zig-Bee? I am starting to think this is the way it's going. -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones@charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=356265#356265 ________________________________ Message 6 _____________________________________ Time: 05:04:32 PM PST US From: "B Tomm" Subject: RE: AeroElectric-List: Re: Canopy Switch -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Friday, October 28, 2011 1:20 PM Subject: Re: AeroElectric-List: Re: Canopy Switch --> At 12:00 PM 10/28/2011, you wrote: > > >Jeff, Bob N, Joe, everyone else, > > If someone isn't crazy about the mechanical "open/closed switch" > in the circuit, would it >be a better (as in more robust) idea to have an optical switch? A >simple tab on the canopy, properly positioned, could open/close an >optical switch as needed. > > Just wondering....... Another option is a reed-switch operated by a magnet. 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