---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Wed 03/13/13: 10 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:25 AM - DISCONNECTING BATTERY WHILE ENGINE IS RUNNING (racerjerry) 2. 07:50 AM - Re: DISCONNECTING BATTERY WHILE ENGINE IS RUNNING (Robert L. Nuckolls, III) 3. 08:07 AM - Re: 24x7diy LED noise experiment (update) (Robert L. Nuckolls, III) 4. 08:12 AM - Re: 24x7diy LED noise experiment (update) (Jeff Page) 5. 08:22 AM - Re: WigWag's resistors for HID circuit (Robert L. Nuckolls, III) 6. 10:09 AM - Re: WigWag's resistors for HID circuit (hotwheels) 7. 10:49 AM - Re: Re: WigWag's resistors for HID circuit (B Tomm) 8. 11:57 AM - Re: WigWag's resistors for HID circuit (hotwheels) 9. 01:44 PM - Re: Re: WigWag's resistors for HID circuit (Robert L. Nuckolls, III) 10. 11:36 PM - Re: 24x7diy LED noise experiment (update) (Holger Selover-Stephan) ________________________________ Message 1 _____________________________________ Time: 05:25:57 AM PST US Subject: AeroElectric-List: DISCONNECTING BATTERY WHILE ENGINE IS RUNNING From: "racerjerry" QUOTE: I've verified this both on cars and airplanes where disconnection of the battery while the alternator is running produces a only a small rise in bus noise. WOW With an alternator system (as opposed to generator), I would be very afraid to disconnect the battery while the engine is running. Many years ago, while doing an operational check on a piece of aircraft ground equipment (cargo loader), the battery became disconnected (corrosion/looseness) from the alternator charging system and apparently the alternator voltage increased to many times its normal output and immediately burned out every light bulb on the vehicle. I was about 50 feet away at that time and I will never forget hearing the engine bog down and turning around to see all the vehicles flood lights going off like flashbulbs. This source claims that such problems occur regularly but not all of the time: http://www.troubleshooters.com/dont_disconnect_battery.htm I only had to replace light bulbs. With all the modern electronics in newer cars and airplanes, I shudder to think of the costs involved should a similar event occur today. This was a very early alternator system with an external regulator; Ford, I believe (although it could have been a Chrysler system). Has something changed where disconnection of a battery from an alternator charging system is no longer as dangerous? -------- Jerry King Read this topic online here: http://forums.matronics.com/viewtopic.php?p=396145#396145 ________________________________ Message 2 _____________________________________ Time: 07:50:55 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: DISCONNECTING BATTERY WHILE ENGINE IS RUNNING At 07:24 AM 3/13/2013, you wrote: QUOTE: I've verified this both on cars and airplanes where disconnection of the battery while the alternator is running produces a only a small rise in bus noise. WOW. With an alternator system (as opposed to generator), I would be very afraid to disconnect the battery while the engine is running. Alternator performance sans battery is a function of regulator design. Indeed, there have been instances of poor regulator design but I suspect that those are pretty much a thing of the distant past. Consider that alternators are manufactured by the millions per year and intended for service in very uncontrolled situations. Situations that must include inadvertent disconnection of the battery. Folks who supply such products would be well advised to consider this possibility in their product development design goals. In fact, modern regulator design specs call for ability to withstand worst case load dumps (sudden disconnection of battery and system demands while heavily loaded). In the current chapter on alternators, I describe a demonstration I witnessed at the Motor Car Parts of America development labs a few years back. I watched a technician disconnect a heavily loaded alternator's b-lead 5 times in a row. The flash of light from the arc precluded taking any video of the event. I tried two times. I wish I had 'scope traces for the b-terminal voltage. The energy release was impressive! The alternator's regulator took it all in stride and continued to function after 5 trials by lighting. The Bonanza has allowed battery-off, alternator-only ops ever since I can remember. I did the regulator design for the pad- driven standby generator about 1979. Beech liked the design and asked for an alternator version too. The specification control drawing required a well behaved alternator without battery. Those alternators had enough retentivity in the field-pole material to self excite. So another feature of the regulator's specification control drawing called for the regulator to come-alive and bring the alternator on line with just a couple of volts of residual output from an un-excited alternator. I don't think the Bonanza (and probably Barons) ever had the functional equivalent of the split-rocker master switch designed to preclude alternator-only operations. The only conversations I recall at Cessna during the split-rocker evolution was a concern about making sure the alternator had battery voltage to come on line . . . I don't think anyone was concerned about alternator-only ops being problematic but the split-rocker thing made it unnecessary to even consider it. There's an interesting story about that self-excitation thing. About 15 years ago, Beech receiving inspection rejected a batch of new alternators for failure to self-excite. This brought a lot of consternated alternator sales and engineering folks to Beech to see what all the fuss was about. It seems that the self-excitation feature for these machines was never a documented requirement or design goal. They just happened to work that way. So for 20+ years, Beech was writing specs to exploit the feature. At the same time, the alternator guys were unaware of Beech's expectations that self- excitation be consistently demonstrable. Hence their surprise when purchasing sent them a 'ding letter' complaining about failure to demonstrate self-excitation during receiving inspection. I don't know what was ultimately done to renew the flow of alternators to the Bonanza and Baron lines but I'm sure they worked it out! In retrospect, I'm pretty sure the designs we were producing back then would not withstand the load-dump test I described above. There was no requirement to demonstrate it. I wonder if it has been added since. I'll have to ask. Bob . . . ________________________________ Message 3 _____________________________________ Time: 08:07:11 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: 24x7diy LED noise experiment (update) At 11:24 PM 3/12/2013, you wrote: > > >OK, fair enough. My investment is time while waiting for another >report from you, and some $150 for the lights. Should I, and maybe >others, contribute to expenses of this experiment? Having an >off-the-shelf, sub $200 landing light pair should be of interest to >a few others as well. And yes, no guarantee for noise levels. I don't think there's much value in waiting for me or anyone else to put a band-aid on any particular COTS offering for lights. That market is evolving very rapidly and as OBAM aviation participants, limiting our selection of products to those which have be successfully 'bandaged' is counter-productive. I think I've written on these pages numerous times that I've never encountered a noise problem that couldn't be whipped. With that assertion in mind, I would encourage folks to try anything that floats their boat. If it produces light sufficient to your needs then let's tackle noise problems as a separate issue. Dollars is not the limiting factor for my efforts, it's time. Further, the time thing is more involved than having a clear bench or wrestling with procurement delays. The elegant solution has to be tempered against the tools I have to produce it along with trading out assembly methods and techniques. I can tell you that what I'm carving on now for the 24x7diy assemblies is in its third generation. The risk is that once the elegant solution for 24x7diy is achieved, they might go out of business or something better might come along. That's the down-side of OBAM aviation. Things done on the TC side of the house tend to become carved in stone. Some of my designs at Electro-Mech are still in production after 30 years. Many of those out of production were canned because critical components are not made any more! Things we do in OBAM aviation are more likely to be pushed overboard because something better came along, not because critical parts have reached end of market life. It's a different ball game entirely. So I would advise you to search out and try lighting products that meet your design goals . . . let's whip what ever noise issues arise later. Bob . . . ________________________________ Message 4 _____________________________________ Time: 08:12:37 AM PST US From: Jeff Page Subject: AeroElectric-List: Re: 24x7diy LED noise experiment (update) > It occurs to me that we could do a HID version > of this flasher that automatically forces a > one-minute warm up period before allowing wig-wag > operations to commence. XeVision has a patent on the "technique" of delaying flashing until the lamps have warmed up. http://xevision.com/hid_pulsing.html Many of their ballasts have a control input that allows flashing without switching the power to the ballast. Jeff Page Dream Aircraft Tundra #10 ________________________________ Message 5 _____________________________________ Time: 08:22:17 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: WigWag's resistors for HID circuit At 01:21 AM 3/13/2013, you wrote: Bob, I had not considered a spike coming back from the input of the ballast. Could flashing the HID's (properly pre-heated or not) damage other electronic equipment onboard the typical aircraft, ie expensive radios and Nav stuff? No. The 'spike' would be an artifact of inductive features in the design of the ballast. Just as the spike suppression diode across a contactor coil protects the controlling switch, I suspect that similar measures for interfacing a solid state flasher with HID ballasts has a similar makeup. The risks are limited to the controlling device; FETS in the controller or in the case of battery contactors, the master switch. The worry that such spikes represent any hazard to the rest of the system is a myth borne out of misunderstanding nonetheless widely circulated. I would like to try the flasher from B and C. Can you point me to a source for suitable resistors? http://tinyurl.com/a62m9mx Check with local electronics suppliers too. This is not a rare part. 75 ohms, 5W, wire wound. Depending on your installation, you might find these more attractive. They have mounting ears. http://tinyurl.com/akqxrd7 I look forward to the results of your experimentation with the HIDs. Keep in mind that you should operate your lamps continuously for about a minute before you revert to wig-wag mode. Bob . . . ________________________________ Message 6 _____________________________________ Time: 10:09:40 AM PST US Subject: AeroElectric-List: Re: WigWag's resistors for HID circuit From: "hotwheels" Hi, I have two 55w HID landing lights (P/N MR16) sourced from rigidindustries.com and the "low-tech" flasher obtained from B&C. I was only able to get flashing going by using the load resistors (from ebay). Works great so long as you give the HIDs adequate warm up time. Cheers, Jay N433RV RV-10 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=396186#396186 Attachments: http://forums.matronics.com//files/wig_wag_606.pdf ________________________________ Message 7 _____________________________________ Time: 10:49:49 AM PST US From: "B Tomm" Subject: RE: AeroElectric-List: Re: WigWag's resistors for HID circuit Jay, The website you site doesn't show HID, only LED. Can you confirm which HID your have, and approximately how many hours of run time with the flasher so far? Thanks Bevan -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of hotwheels Sent: Wednesday, March 13, 2013 10:03 AM Subject: AeroElectric-List: Re: WigWag's resistors for HID circuit --> Hi, I have two 55w HID landing lights (P/N MR16) sourced from rigidindustries.com and the "low-tech" flasher obtained from B&C. I was only able to get flashing going by using the load resistors (from ebay). Works great so long as you give the HIDs adequate warm up time. Cheers, Jay N433RV RV-10 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=396186#396186 Attachments: http://forums.matronics.com//files/wig_wag_606.pdf ________________________________ Message 8 _____________________________________ Time: 11:57:36 AM PST US Subject: AeroElectric-List: Re: WigWag's resistors for HID circuit From: "hotwheels" They may have discontinued HID sales, and the name changed since I purchased... Used to be planelights.com. I've been running them for Read this topic online here: http://forums.matronics.com/viewtopic.php?p=396202#396202 ________________________________ Message 9 _____________________________________ Time: 01:44:31 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: WigWag's resistors for HID circuit At 12:03 PM 3/13/2013, you wrote: > >Hi, > >I have two 55w HID landing lights (P/N MR16) sourced from >rigidindustries.com and the "low-tech" flasher obtained from B&C. I >was only able to get flashing going by using the load resistors >(from ebay). Works great so long as you give the HIDs adequate warm up time. Good information! Thanks for sharing. Bob . . . ________________________________ Message 10 ____________________________________ Time: 11:36:10 PM PST US Subject: Re: AeroElectric-List: 24x7diy LED noise experiment (update) From: Holger Selover-Stephan On Mar 13, 2013, at 8:06 AM, Robert L. Nuckolls, III wrote: > I don't think there's much value in waiting > for me or anyone else to put a band-aid on > any particular COTS offering for lights. > That market is evolving very rapidly and as > OBAM aviation participants, limiting our > selection of products to those which have > be successfully 'bandaged' is counter-productive. OK, understood, Bob. If it's that much of a moving target. I'll pipe up again when I have the lights and checked for noise. Very much appreciate the time you took to explain the situation. 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