---------------------------------------------------------- Pulsar-List Digest Archive --- Total Messages Posted Wed 08/21/13: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 09:16 AM - Re: Re: [Pulsar-Aviators] New Stator Coil In - Flying Again (dougwitkowski@netscape.net) 2. 08:16 PM - parts (Rex Miller) 3. 08:25 PM - Have great time in LWC! (Casey King) 4. 08:25 PM - Have great time in LWC! (Casey King) ________________________________ Message 1 _____________________________________ Time: 09:16:22 AM PST US Subject: Re: Pulsar-List: Re: [Pulsar-Aviators] New Stator Coil In - Flying Again From: dougwitkowski@netscape.net Ron, Great discussion! I assumed that failure on shutdown was 'common' knowledge as it was told to me by both Green Skys and Leading Edge folks. Never really delved into th e 'why' of how the failures are claimed to happen. You are probably right in that it's not a voltage spike. More likely stres ses caused by the grounding action. The charging coil will experience a mechanical jolt and a momentary high cu rrent flow when the coil is grounded. That could fatigue the coil or chafe the insulation. There is also a bridge rectifier between the charging coil and the capacito r. It has to hold back the voltage as it's built in the capacitor with eac h charging coil pulse. Even at the zero voltage point, there is resistance in the charging coil. When the coil is grounded, the rectifier has to hol d back what could be a full charge (before the system fires the plugs) agai nst a zero resistance short. Either of these scenarios could be the cause of a 'failure at shutdown' situation. I doubt the capacitor or the SCR would experience any stress from the groun ding. Keep up the discussion at LWC, I'm sure it will be very interesting. Doug W -----Original Message----- From: Ron Koval Sent: Tue, Aug 20, 2013 2:30 pm Subject: Re: Pulsar-List: Re: [Pulsar-Aviators] New Stator Coil In - Flying Again Doug, Forgive me for not having heard, ignition systems fail on shutdown. I find that very hard to believe, understanding how they work and how we shut our ignition down for mag checks. In our CDI ignition system the stator coil charges up a capacitor, then a s econd coil triggers an SCR (solid state device; silicon controlled rectifie r) and discharges the capacitor into the ignition coil which has a step up winding that fires the spark plug. All we do to shut this down is ground t he very front end of the process, by grounding the stator coil so no charge is provided to the module that houses the capacitor. Lycomings, Continent al engines do the same except, they use the magnetic field of mag coil, ope n a set of grounding points, which produces a sudden magnetic field change, which then causes current to flow in the primary coil, and the secondary c oil step up winding fires the spark plug. They also, at the front end, gro und the primary coil using the P-lead to disable ignition. The only thing that is getting beat up during a mag check is the mag switch. Our ignition systems are not very susceptible to spikes or noise, because t hey are the worst source, the culprit of the greatest transients and noise in our aircraft. With the faults that I have found at the connectors coupling the wires from stator coil to the CDI module, the most likely root cause is vibration mec hanically breaking the wire at the connector. I have one more side of the stator coil to find out where it broke down. I am very anxoius to find thi s other fault and protentially be able to fix it and have a back up stator coil. Best regards, Ron From: "dougwitkowski@netscape.net" Sent: Monday, August 19, 2013 10:06 AM Subject: Pulsar-List: Re: [Pulsar-Aviators] New Stator Coil In - Flying Aga in Common knowledge is that ignition systems fail on shutdown (possible voltag e spikes??). Testing pre-shutdown probably won't help, the testing itself may cause the failure. In my mag check procedure, it's not the RPM drop t hat's important, it's the return to normal RPM on 'both' that is important. -----Original Message----- From: Ron Koval To: Pulsar B uilders ; Pulsar-Aviators Sent: Mon, Aug 19, 2013 9:50 am Subject: [Pulsar-Aviators] New Stator Coil In - Flying Again Pulsar Friends, Put in the new stator coil in my 582 and ran it through 4 rounds of touch and goes Sunday evening. Relief ... the Pulsar and I are looking forward t o the convention. After this experience, I learned and added a step to my engine shut down pr ocedure, do a mag check. It is nice to know that you completed your flight with both mags still working and if one ignition circuit, perhaps fails, d ue to everything under the cowl at high temperatures, it is nice to know. Also if this were perhaps the flight that one ignition circuit fails (more likely to fail engine running than in the hanger), it is better to know now rather than on the ramp wanting to take off per plan. I discovered that in my defective stator coil there were 2 intermittent con nections, right at the rubber 2 conductor connector of my defective stator coil. I am on a mission to find out where the other side charging coil is open. It would be nice to discover that it also has a simple connector wir e problem and not an open within one of the 2 coils that make up the chargi ng circuit. Even after taking extra care to clean all of the contacts (grounds, power . ..) putting everything back together with the new stator coil, my analog ta ch is reading way high. Fortunately my digital tach is what I reference. Last time I fixed it, I added a stainless steel external tooth lock washer on the heavy ground to dig into the metal surfaces and provide a good conne ction to the engine block (but I cleaned this terminal again and still have the lock-washer in place. Looking forward to the convention. Ronko __._,_.___ Reply via web post Reply to sender Reply to group Start a New Topic Messages in this topic (1) Recent Activity: New Members 1 New Photos 5 Visit Your Group Switch to: Text-Only, Daily Digest =A2 Unsubscribe =A2 Terms of Use =A2 Send us Feedback .. __,_._,___ ark>Un/Subscription, ore: >Dralle, List Admin. ark>Un/Subscription, ore: >Dralle, List Admin. -= - The Pulsar-List Email Forum - -= Use the Matronics List Features Navigator to browse -= the many List utilities such as List Un/Subscription, -= Archive Search & Download, 7-Day Browse, Chat, FAQ, -= Photoshare, and much much more: - -= --> http://www.matronics.com/Navigator?Pulsar-List - -======================== -= - MATRONICS WEB FORUMS - -= Same great content also available via the Web Forums! - -= --> http://forums.matronics.com - -======================== -= - List Contribution Web Site - -= Thank you for your generous support! -= -Matt Dralle, List Admin. -= --> http://www.matronics.com/contribution -======================== ________________________________ Message 2 _____________________________________ Time: 08:16:07 PM PST US Subject: Pulsar-List: parts From: Rex Miller I've got a mountain high o2 system for sale, model xrc 180, retail 450, wi ll sell for 300, small and portable perfect for pulsar. epoxy pump. oil thermostat for rotax 8 spark plugs, 912ul a few other things thanks Rex wish i could make larwance ________________________________ Message 3 _____________________________________ Time: 08:25:21 PM PST US From: Casey King Subject: Pulsar-List: Have great time in LWC! I too wish I could see everybody in KS. Next time I will! Look forward to hearing reports. Casey ________________________________ Message 4 _____________________________________ Time: 08:25:22 PM PST US From: Casey King Subject: Pulsar-List: Have great time in LWC! I too wish I could see everybody in KS. Next time I will! Look forward to hearing reports. 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