---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 05/11/20: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 09:01 AM - Re: Rotax/Ducati alternator webpage (Robert L. Nuckolls, III) 2. 01:24 PM - Re: Re: Crossover Light on (skywagon185guy .) 3. 05:58 PM - Re: DC clamp meter (blues750) 4. 08:20 PM - Re: Re: DC clamp meter (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 09:01:24 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Rotax/Ducati alternator webpage At 05:37 PM 5/10/2020, you wrote: >Le 10/05/2020 =C3 19:57, Charlie England a =C3=A9crit=C2 : >> >>NB:=C2 The frequency is used to determine the rotation speed. >>200 Hz with 5 pairs of poles corresponds to 40 rpm, i.e. 2400 rpm. >>Not really sure what's going on there, with 40 rpm and 2400 rpm. >> >>And of course, we barbarians always struggle >>with temperature measured in C. Not because it >>isn't better, but because we weren't properly schooled. :-) >> >>Otherwise, it was very readable using the Google Translate version. > > >Charlie and all, > >Thank you to those who took the time. > >So Google might be a valuable source after all. > >It is true that we're so picky on style and grammar in my language... > >I'll have a try at it, do not hesitate to >propose a correction if something looks awkward or inaccurate. Gilles, This is an extra-ordinary paper that defines the physics that govern the operation of that particular alternator . . . and offers a benchmark for how all pm alternators should be explored and documented. I'd be pleased to add your work product to the library on aeroelectric.com Bob . . . ________________________________ Message 2 _____________________________________ Time: 01:24:37 PM PST US From: "skywagon185guy ." Subject: Re: AeroElectric-List: Re: Crossover Light on Good catch by both of you electro-types.... Nice easy solution too.... On Sun, May 10, 2020 at 6:45 PM Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > > So..,, since then, I finished wiring in radios etc, and now the cross over > light is on when I turn on only the Aux master (I have installed the Z-14 > dual batt dual alternator). (It's in a Long Ez). Everything seems to work > correctly, starter, crossover, etc. when I turn on the main master I don't > get the light, when I turn on both masters, I don't get the light, it's > just when I turn on only the Aux master. > > > Boy . . . that's a lot of harxware to be > carrying around in an Ez . . . > > You have discovered a 'bug' in the architecture. > A 'sneak path' exists from the hot aux bus thru > the cross-over contactor coil then through > the CROSSOVER WARN light to the DEAD main bus > as a 'ground'. > > See https://tinyurl.com/ydg99c5w > > You can fix this by adding a diode (any handy > size will do) in series with the CROSSOVER WARN > light as shown in the sketch. > > You can install it in the lead wire to the > annunciator fixture. See > > https://tinyurl.com/kyc6tq6 > > for the technique. > > Thanks for the heads-up! I'll update > Z14 to add this fix. > > > Bob . . . > ________________________________ Message 3 _____________________________________ Time: 05:58:40 PM PST US Subject: AeroElectric-List: Re: DC clamp meter From: "blues750" Bob, finally able to do the calculation on how you get a 1 OHM equivalent resistor out of the four resistors rated at 4 ohms in parallel. What a blast from the past! I'll take your word on the Power rating being suitable!! Thank you so much for the help and interest. I can't wait to get some data! Dave (most appreciative novice experimentalist) Read this topic online here: http://forums.matronics.com/viewtopic.php?p=496289#496289 ________________________________ Message 4 _____________________________________ Time: 08:20:01 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: DC clamp meter At 07:54 PM 5/11/2020, you wrote: > >Bob, finally able to do the calculation on how you get a 1 OHM >equivalent resistor out of the four resistors rated at 4 ohms in >parallel. What a blast from the past! I'll take your word on the >Power rating being suitable!! Thank you so much for the help and >interest. I can't wait to get some data! Yup . .. 1 RT = =================================== 1 1 1 1 ____ _____ _____ ______ R1 R2 R3 Rx Rtotal equals the reciprocal of the SUM of reciprocals of all resistors in the array . . . no matter how many resistors. It just so happened that your target current worked out close to a 1-ohm load . . . so the array of 4 x 4 ohms works nicely. The total wattaged needed is much less than to total ratings of thsoe four resistors. They're offered as 100W devices . . . but in practice, they're closer to 50W when adequately heat-sinked. So the sum total of the 4 is comfortably good for 200W. You only need 13A x 13v is 169W. This bucket-o-resistors technique is very versatile. For example, a couple years ago I crafted a portable, 750 watt, variable load bank for the purpose of airborne cooling tests on alternators. An array of 21 resistors not unlike the ones I suggested plus a handful of components and a fan made for a device that would offer loads from 0 to approx 50A fan cooled. I've used this technique to craft load banks up to 2800 watts (28v, 100A) . . . with a lot more resistors and a bigger fan . . . but knob-adjusted at the control panel. Bob . . . ------------------------------------------------------------------------------------- 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.