---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 12/25/12: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:43 AM - Re: Problem with the Harbor Freight Carbon Pile battery tester (Bill Watson) 2. 10:45 PM - Switches all upside-down... (Michael Burbidge) 3. 11:24 PM - Re: Switches all upside-down... (Eric Page) ________________________________ Message 1 _____________________________________ Time: 06:43:19 AM PST US From: Bill Watson Subject: Re: AeroElectric-List: Problem with the Harbor Freight Carbon Pile battery tester All is well now. Not exactly sure what my problem was but I suspect that 1) at some point I had completely unscrewed the knob and 2) one of the carbon disk got out of position and got jammed. But I can't be sure. For those interested, I made some additional notes among those already made at the bottom of this note. So I proceeded on with the task I had in mind. I run a Z-14 with dual PC680s. It seemed that one of my batteries is below par. In cold weather 1 of my 3 GRT HX screens will not boot up before engine start and the alternator comes on line. The plan has always been to keep the best battery on the starter circuit so I figured it may be time to get a new one and swap the starter battery to the GRT circuit. In addition, I get a solid warning light from the LRC3 regulator on that circuit. I'm not sure that is a battery problem at all but hoping it may clear up too. Even though I've only been flying the RV10 for 1.5 years, I've been playing with PC680s for 6 or 7 years now. With the latest purchase, I now have 5 batteries (!!). I've hurt 1 or 2 of them by using them heavily and recharging them exclusively with a trickle charger before I learned better. By the time the plane was flying, they wouldn't charge up to full capacity. But the task at hand was to test the performance of all 5 batteries to confirm selection of the best two. Here is the test and the results. The battery numbers reflect the sequence of purchase. (Temp = 62F) Initial Voltage Voltage 30min after load Battery 24hrs after charge 120amps for 15 sec Batt1 12.71 12.56 Batt2 13.10 13.02 Batt3 13.00 12.84 Batt4 12.99 12.86 Batt5 13.15 13.08 I had been using Batts 2&3. Now I will be moving 3 out of the plane, putting 2 in it's place and using Batt5 on the starter circuit. Interestingly, I would have come to same conclusions using the first column of numbers (without load testing) that I would have based on the load testing. Battery 4 is the 'aviation version' of the PC680. Right out of the box, It never performed as well as the standard PC680s, even though there is no apparent external difference other than mention of "PMA" and it's all orange color. In the end, it's never been in the plane. Thanks Bob and everyone! Bill Watson On 12/24/2012 10:09 AM, Robert L. Nuckolls, III wrote: > > > At 06:25 PM 12/23/2012, you wrote: >> >> >> I've used this unit a few times without a problem. Then it suddenly >> stopped working. I couldn't seem to apply a load though the exact >> symptoms I don't quite remember. > > is it failing to APPLY a load or failing to > INDICATE what that load is? Does the voltmeter > behave as expected? Can you depress the voltmeter > reading and get it to smell hot by cranking the > load knob down? Voltmeter was working fine. Cranking the knob resulted in no change, no smell. I think the know was jammed by a disk being out of position. > > >> Today, I pulled the unit apart and found >> 1) a fuse on a small circuit board which had not blown (not easily >> replaceable either) >> 2) the carbon disks that presumably supplies the variable resistance >> seem to be stacked between two steel plates but the carbon disks >> appeared to be loose or askew. > > Those are classically not tightly captive. > A carbon pile rheostat is a PRESSURE device > wherein once the slack is taken out of the > stack height by the first turn of load knob > rotation, the pile doesn't physically move > much after that. It's behavior is a response > to pressure not motion. That makes sense. > >> If I screw the big knob down and shake things a bit, I can get the >> stack of carbon plates lined up and it seems that increased >> resistance results from placing more pressure on the stack. >> >> Does that sound right? > > No, the resistance between the fat wires to hte > battery should drop markedly. To load a battery > to 500A at 8 volts requires a resistance on > the order of 16 MILLIOHMS. My mistake here - I was referring to physical resistance on the knob, not electrical resistance > > >> Furthermore, it would seem for consistent operation, it would be best >> to lie the unit on its back to insure the carbon plates remain flat. > > Doesn't matter. > > >> Tomorrow I will attempt to use it again to see if it works now that >> the plates are back in position. >> >> Any insight or tips welcome. I will report further tomorrow. > > I've got two of these critters and they've > performed as expected for 5+ years. Sounds > like something may be unhooked. Tell us what > behaviors you see on the voltmeter while trying > to get the load increased. > > > Bob . . . > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > > ________________________________ Message 2 _____________________________________ Time: 10:45:27 PM PST US From: Michael Burbidge Subject: AeroElectric-List: Switches all upside-down... I just mounted my instruments and switches in my beautifully painted panel. To my dismay I discovered that when I cut my panel, many months ago, I drilled the key hole for all my B&C switches on the top instead of the bottom of the main hole. This means that all my switches are upside down. Off is up and on is down. ARG! I'm thinking I'm going to have to fill the key holes with putty and drill new ones on the bottom. But I thought I'd check real quick to see if there is a alternate keyed washer that would allow be to rotate the switches 180 degrees. Thanks for any suggestions! Michael- ________________________________ Message 3 _____________________________________ Time: 11:24:15 PM PST US Subject: Re: AeroElectric-List: Switches all upside-down... From: Eric Page Can the key be bent 180 deg to face the opposite side of the washer without breaking off? If it makes you feel any better, many airliners have their switches mounted the way you've done yours. Of course, they're on the overhead panel, so forward is on and aft is off... Eric On Dec 25, 2012, at 11:43 PM, Michael Burbidge wrote: > > I just mounted my instruments and switches in my beautifully painted panel. To my dismay I discovered that when I cut my panel, many months ago, I drilled the key hole for all my B&C switches on the top instead of the bottom of the main hole. This means that all my switches are upside down. Off is up and on is down. ARG! > > I'm thinking I'm going to have to fill the key holes with putty and drill new ones on the bottom. But I thought I'd check real quick to see if there is a alternate keyed washer that would allow be to rotate the switches 180 degrees. > > Thanks for any suggestions! > Michael ------------------------------------------------------------------------------------- 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.