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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Actually the long wires add inductance which can cause voltage spikes as a result of the fast switching. This can blow the devices (MOSFET) used to switch the currents.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>It can overvoltage the caps also but that may not be the main problem.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>I had some trouble like this when I designed my controller.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Ken Martindale<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>From:</span></b><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'> Personal_Submersibles [mailto:personal_submersibles-bounces@psubs.org] <b>On Behalf Of </b>Alan James via Personal_Submersibles<br><b>Sent:</b> Saturday, June 06, 2015 6:48 PM<br><b>To:</b> Personal Submersibles General Discussion<br><b>Subject:</b> Re: [PSUBS-MAILIST] Dive report: Snoopy at Seneca<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div id="yui_3_16_0_1_1433621245176_12450"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'>Thanks for the report Alec, great stuff.<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433621245176_12450"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'>re the motor controllers; I've been reading a bit about inductance in long wire runs from battery to<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433621245176_12450"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'>motor controllers, that harms the capacitors on the controllers.<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433621245176_12450"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'>This could be a problem that is unique to our submarines & not an issue with things like golf carts<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433621245176_12450"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'>& wheel chairs.<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433621245176_12450"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'>My reading has been mainly about BLDC motor controllers but asume PWM controllers for brushed<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433621245176_12450"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'>motors would be similar. Because of the rapid switching on & off of the power to the motor, there is a<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433621245176_12450"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'>current surge hitting the capacitors & the longer the wire run, the more the power in the surge.<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433621245176_12450"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'>A water analogy would be turning a valve off suddenly as washing machines do, sometimes with<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433621245176_12450"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'>a "thunk" sound & a rattle of the pipes.<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433621245176_12450"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'>Hugh mentioned he had problems with his Curtis BLDC motor controllers.<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433621245176_12450"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'>Attached is the problem & solution, which is to put capacitors in parrallel along the battery wire; <o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433621245176_12450"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'>however there must be a better way.<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433621245176_12450"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'>Regards Alan<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433621245176_12450"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'><a href="http://www.rcgroups.com/forums/showthread.php?t=952523">too long battery wires will kill ESC over time: precautions, solutions & workarounds - RC Groups</a><o:p></o:p></span></p></div><div style='margin-top:3.75pt;margin-bottom:3.75pt' id="enhancrCard_0"><table class=MsoNormalTable border=0 cellspacing=0 cellpadding=0 width=675 style='width:337.5pt;border-collapse:collapse'><tr style='height:.75pt'><td colspan=8 style='background:#E5E5E5;padding:0in 0in 0in 0in;height:.75pt'><div><p class=MsoNormal style='mso-line-height-alt:0pt;background:#E5E5E5'><span style='font-size:1.0pt'> <o:p></o:p></span></p></div></td></tr><tr style='height:4.5pt'><td width=2 rowspan=5 style='width:.75pt;background:#E5E5E5;padding:0in 0in 0in 0in;height:4.5pt'><div><p class=MsoNormal style='background:#E5E5E5'><span style='font-size:1.0pt'> <o:p></o:p></span></p></div></td><td width=252 rowspan=5 style='width:1.75in;background:black;padding:0in 0in 0in 0in;height:4.5pt'><p class=MsoNormal align=center style='text-align:center'><a href="http://www.rcgroups.com/forums/showthread.php?t=952523"><span style='text-decoration:none'><img border=0 width=168 height=168 id="_x0000_i1025" src="http://static.rcgroups.net/forums/customavatars/avatar3018_10.gif" alt=image></span></a><o:p></o:p></p></td><td width=2 rowspan=5 style='width:.75pt;background:#E5E5E5;padding:0in 0in 0in 0in;height:4.5pt'><div><p class=MsoNormal style='background:#E5E5E5'><span style='font-size:1.0pt'> <o:p></o:p></span></p></div></td><td width=21 rowspan=5 style='width:10.5pt;background:white;padding:0in 0in 0in 0in;height:4.5pt'><div><p class=MsoNormal style='background:white'><span style='font-size:14.0pt'> <o:p></o:p></span></p></div></td><td colspan=2 style='background:white;padding:0in 0in 0in 0in;height:4.5pt'><div><p class=MsoNormal style='background:white'><span style='font-size:6.0pt'> <o:p></o:p></span></p></div></td><td width=30 rowspan=5 style='width:15.0pt;background:white;padding:0in 0in 0in 0in;height:4.5pt'><div><p class=MsoNormal style='background:white'><span style='font-size:20.0pt'> <o:p></o:p></span></p></div></td><td width=2 rowspan=5 style='width:.75pt;background:#E5E5E5;padding:0in 0in 0in 0in;height:4.5pt'><div><p class=MsoNormal style='background:#E5E5E5'><span style='font-size:1.0pt'> <o:p></o:p></span></p></div></td></tr><tr><td width="100%" colspan=2 style='width:100.0%;padding:0in 0in 0in 0in'><div><div><p class=MsoNormal style='line-height:12.4pt;background:white;word-break:break-all'><span style='font-family:"Georgia",serif'><a href="http://www.rcgroups.com/forums/showthread.php?t=952523"><span class=link-enhancr-element><span style='font-size:13.5pt;color:black'>too long battery wires will kill ESC over time: precauti...</span></span></a><o:p></o:p></span></p><div><p class=MsoNormal style='line-height:15.0pt;background:white;word-break:break-all'><span style='font-size:10.0pt;font-family:"Georgia",serif;color:#999999'>Careful! too long battery wires will kill ESC over time: precautions, solutions & workarounds Electric Plane Talk<o:p></o:p></span></p></div></div></div></td></tr><tr style='height:3.0pt'><td colspan=2 style='background:white;padding:0in 0in 0in 0in;height:3.0pt'></td></tr><tr><td style='padding:0in 0in 0in 0in'><div><p class=MsoNormal><span style='font-size:1.0pt;font-family:"Arial",sans-serif'><a href="http://www.rcgroups.com/forums/showthread.php?t=952523" target="_blank"><span class=link-enhancr-element><span style='font-size:7.0pt;color:#999999'>View on </span></span><span class=link-enhancr-view-on-domain><b><span style='font-size:7.0pt;color:#999999'>www.rcgroups.com</span></b></span></a><o:p></o:p></span></p></div></td><td width=150 style='width:75.0pt;padding:0in 0in 0in 0in'><p class=MsoNormal align=right style='text-align:right;line-height:8.25pt'><span class=link-enhancr-element><span style='font-size:7.0pt;font-family:"Arial",sans-serif;color:#999999'>Preview by Yahoo</span></span><span style='font-size:1.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p></td></tr><tr style='height:6.75pt'><td colspan=2 style='background:white;padding:0in 0in 0in 0in;height:6.75pt'></td></tr><tr style='height:.75pt'><td colspan=8 style='background:#E5E5E5;padding:0in 0in 0in 0in;height:.75pt'><div><p class=MsoNormal style='mso-line-height-alt:0pt;background:#E5E5E5'><span style='font-size:1.0pt'> <o:p></o:p></span></p></div></td></tr><tr height=0><td width=1 style='border:none'></td><td width=168 style='border:none'></td><td width=1 style='border:none'></td><td width=7 style='border:none'></td><td width=270 style='border:none'></td><td width=217 style='border:none'></td><td width=10 style='border:none'></td><td width=1 style='border:none'></td></tr></table></div><div id="yui_3_16_0_1_1433621245176_12450"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'><o:p> </o:p></span></p></div><div id="yui_3_16_0_1_1433621245176_12450"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'><o:p> </o:p></span></p></div><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'><o:p> </o:p></span></p><div id="yui_3_16_0_1_1433621245176_12453"><div id="yui_3_16_0_1_1433621245176_12452"><div id="yui_3_16_0_1_1433621245176_12451"><div class=MsoNormal align=center style='text-align:center;background:white'><span style='font-family:"Helvetica",sans-serif;color:black'><hr size=1 width="100%" align=center></span></div><p class=MsoNormal style='background:white'><b id="yui_3_16_0_1_1433621245176_16535"><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>From:</span></b><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'> hank pronk via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br><b id="yui_3_16_0_1_1433621245176_16533">To:</b> Personal Submersibles General Discussion <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> <br><b id="yui_3_16_0_1_1433621245176_16531">Sent:</b> Sunday, June 7, 2015 12:20 AM<br><b id="yui_3_16_0_1_1433621245176_16528">Subject:</b> Re: [PSUBS-MAILIST] Dive report: Snoopy at Seneca</span><span style='font-family:"Helvetica",sans-serif;color:black'><o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433621245176_12454"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'><br>Alec,<br>I don't know what type of speed controller you are using, but I like and use Curtis golf cart controllers. They are rated for huge amperage and seem bullet proof. I have an extra 36V controller I can send you to try out. They use a 10 OHM potentiometer for the throttle. They also have a battery protection mode, a sort of get home conservation mode. <br>I labeled the motor in Gamma for a jumper cable, so that I can get home without the controller. As you said it is electronic and it will fail.<br>If you want the controller send your address of list.<br>Hank<br>--------------------------------------------<br>On Fri, 6/5/15, Alec Smyth via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org" id="yui_3_16_0_1_1433621245176_19349">personal_submersibles@psubs.org</a>> wrote:<br><br>Subject: [PSUBS-MAILIST] Dive report: Snoopy at Seneca<br>To: "Personal Submersibles General Discussion" <<a href="mailto:personal_submersibles@psubs.org" id="yui_3_16_0_1_1433621245176_19348">personal_submersibles@psubs.org</a>><br>Received: Friday, June 5, 2015, 6:16 PM<br><br>Hello friends,<br>I just got back from a dive trip to Seneca with<br>Dan Lance and thought I'd share how it went. This was<br>supposed to be a two sub trip with Scott Waters, but<br>unfortunately a business emergency intervened and it ended<br>up being just Snoopy.<br>On the way up the weather was terrible, with<br>driving rain so heavy I could barely see the lines on the<br>road. It had been raining heavily for several days<br>previously. Three times there were emergency announcements<br>about floods, large hail, and damaging winds, and the closer<br>I got the harder it rained. The problem with all that rain<br>is that in your typical lake, the runoff ruins visibility<br>for weeks. That is what happened last year when Trustworthy<br>and Snoopy rendezvoused at Summersville Lake, and it looked<br>very much like this would be a repeat. I'm happy to say<br>Seneca must be rain-proof, because the deluge only reduced<br>the visibility in the top fifty feet or so, and even those<br>were clearer than most lakes.<br>Here's a few things we learned:<br>1) Of props and shroudsThe stern<br>thruster speed control was dead on arrival, although I had<br>tested it successfully before leaving. I opened up the<br>enclosure, pressed down all the spade connectors, and found<br>it now worked - so attributed the issue to road bumps.<br>However, it died within a minute on the first dive. I had a<br>spare speed controller, so switched it out. <br>The replacement died within five minutes on the<br>second dive. This time at least the cause was obvious, the<br>prop was jammed by weeds. The current Minnkota props have a<br>little twist at the end of the blades, and Snoopy's<br>shroud is made with almost no clearance. The little twist to<br>the blade tip causes any object coming between prop and<br>shroud to jam tight, and had already smoked one controller<br>during the convention in the Keys. I'm going to put the<br>prop on the lathe and take off the tips to eliminate the<br>pinching effect and to reduce the amperage draw a little so<br>the motor goes lighter on the speed controller. By the way,<br>the speed controller was protected by a fuse rated a little<br>below the controller spec current draw, so perhaps those<br>specs are optimistic. Anyway, as a result of the double<br>failure all of our dives were done on just the side<br>thrusters because I was out of spare speed controllers.<br>Lesson for next sub: Design the electrical system with a<br>controller bypass, so I can operate thrusters with simple<br>on/off switches if a speed controller fails. They're<br>electronic, they will fail.<br>2) Of air bubbles in compensation oil<br>Snoopy is now routinely diving deep (250 ft) and<br>this has showed up a puzzling issue with the thrusters. They<br>were feeble during dives, one died altogether on one dive,<br>and they kept coming up leaking oil. At first we thought the<br>seals were failing, perhaps due to some chemical<br>incompatibility. We found suitable seals at an Amish farm<br>supply store that sold things like tractor spares (viva<br>trolling motor simplicity!) When I disconnected the bladder<br>hose I got quite well sprayed with oil. The motor turned out<br>to be pressurized. <br>Previously, I thought if one had a small quantity<br>of air left in the system it would not be an issue so long<br>as the compression volume of that air could be handled by<br>the flexibility of the hose (aka compensation bladder.)<br>Wrong. I now think what happens is that if the dive exceeds<br>the pressure rating of the shaft seal and there is a bubble<br>of any size, you will get water added to the oil and the<br>bubble stores the pressure. Upon surfacing, the bubble<br>squeezes oil and water back out until the pressure in the<br>motor falls to the "cracking pressure" of the<br>seal. Thus, you get an oil leak even though the seals are<br>fine. Lesson: Zero tolerance with oil bubbles, even a small<br>bubble is unacceptable if you are diving deep. I'm going<br>to put set screws on the motor caps so I can get rid of the<br>bubbles more easily.<br>3) An easy way to add<br>buoyancySnoopy's buoyancy is adjusted by<br>placing trawl floats in PVC tubes. On one occasion, the<br>oncoming passenger's weight required the addition of<br>just one float (i.e. the new guy weighed seven pounds more<br>than the one getting off). The support diver wasn't<br>suited up and the water was 42 degrees, so I just pushed a<br>float under the lip of the forward MBT. It worked like a<br>charm, and the float even stayed in place throughout the tow<br>back to the ramp. Lesson: You can easily add a few floats<br>for buoyancy on a standard K sub, no special tubes<br>required.<br>Most of our dives were along a very steep<br>incline, not quite a wall but more like a series of ledges<br>and very steep slopes. Between the steep terrain and the<br>good visibility, the K250 dome for once offered a really<br>good view. We typically made our way down the slopes using<br>very slightly negative buoyancy, trailing the back corner of<br>a skid on the slope. Looking aft, you could see a zigzagging<br>trail of silt hanging motionless in the water and tracing<br>our path. The sub compresses with depth, so slightly<br>positive buoyancy at the surface turned into slightly<br>negative at depth, but we're speaking of just a couple<br>of pounds and not anything that caused difficulty. In fact<br>at one point we stopped dead in the water four or five feet<br>above a flat bottom for about five minutes, just waiting for<br>a pre-arranged touch-point call on comms. The sub didn't<br>rise or sink an inch, she just hung there completely<br>immobile for five minutes. At about 140 feet the visibility<br>would improve significantly, and the water changed from<br>green to blue. It looked like ocean instead of lake water.<br>I'll post a video, but that'll take a few days to<br>put together. The only "incidents" we had were a<br>cold bath we took when we closed the hatch over a corner of<br>the crew's shirt, and when we got hooked on a log at 220<br>feet - fortunately reversing got us right off<br>it.<br><br>Best,<br>Alec <br><br><br><br><br><br>-----Inline Attachment Follows-----<br><br>_______________________________________________<br>Personal_Submersibles mailing list<br><a href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><o:p></o:p></span></p><div><p class=MsoNormal style='margin-bottom:12.0pt;background:white'><span style='font-family:"Helvetica",sans-serif;color:black'><o:p> </o:p></span></p></div><div id=yqtfd66451><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica",sans-serif;color:black'><br><br><br>_______________________________________________<br>Personal_Submersibles mailing list<br><a href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><o:p></o:p></span></p></div><p class=MsoNormal style='margin-bottom:12.0pt;background:white'><span style='font-family:"Helvetica",sans-serif;color:black'><o:p> </o:p></span></p></div></div></div></div></div></body></html>