Toobuilder said:
Are you suggesting the failure rate of Pmags is skewed by the volume of units in operation?
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I have no idea what the actual failure rate of a Pmag is. I don’t know if the bearing issue discovered during routine maintenance is a considered a failure. They are certainly more maintenance intensive than a mag.
 
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Toobuilder said:
Just looking for clarity on your last post because its not apparent in my pea brain
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I’m not necessarily a Pmag advocate. I used one with a regular mag largely based on hype. I find the 100 hour inspection invasive. The attraction of the auto plugs faded when I found out that a third of the recommended NGK auto plugs are counterfeit. I’m just confident the self power part isn’t a concern.
 
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Dad's RV-10 said:
I guess I'm in the minority. I check the internal alternators on every run-up.

My fingers are already on the switches, so why not perform the test?
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Not sure if you are in the minority or not, but its clear there's a good number of pilots who don't. But as a method of fault detection its a pretty course screen. There can be no expectation that the internal generator will continue to work until the next test event. Probably will, but without ongoing fault detection, who knows. It's exactly why we have the "idiot light" for the alternator.
 
Dad's RV-10 said:
I guess I'm in the minority. I check the internal alternators on every run-up.

My fingers are already on the switches, so why not perform the test?
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Same here - I have never done a runup without checking the internal alternators . At annual I also check the rpm that they start to drop out.
 
Mikeyb said:
...I’m just confident the self power part isn’t a concern.
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At the system level (engine runs until landing), I agree. NBD. Same with most other EIs. The engine will run, with reasonable backup schemes in place. At the same time, the "self powered" attribute loses much of its shine due to the less than stellar reliability at the component level. Like most things in aviation its a trade, its a compromise.
 
The data stream provided by the EMAG does include voltage. The raw value doesn't match ship's power so I'd assume this is the voltage that the EMAG is running off of (ship or internal power). The issue I would have creating a warning light is that we have no details on what the range of voltages means. Something like < 10 running on ship >= 10 running internal power for example. Then it would be easy to add in a warning light but without it would just be guessing.
 
I think the indication that the ignition did a mode shift as a discrete event is the data the typical pilot needs.

Failed/not failed... no fuzz on that peach

Edit. Pulling on that thread a little more, it seems a "mode shift" indicator would be great for run up too. Pre engine start the light is on; once stable at idle the light should be out. If not, you don't even have to wait to do your "test" at the end of runway. Further, one could pull the idle way back and see the light come back on when it shifts to external power.

Seems like this light could eliminate a bunch of switch throwing and pre takeoff process. When one of you EE types build this thing please send me the royalties!
 
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Toobuilder said:
I think the indication that the ignition did a mode shift as a discrete event is the data the typical pilot needs.

Failed/not failed... no fuzz on that peach
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The current firmware and data stream provides a mode. But that mode is just 0 for startup mode and 1 for normal operation. To back into the internal alternator working you would have to know what voltage ranges provided in the stream corresponded to ship power vs internal power or if that was even feasible to use as a logic test. Takes less than 10 seconds to a check during runup but it would be nice to have an indicator during flight if the internal failed. If I ever get some time I'll add the voltage to to my screen and see if I can't figure out a correlation.
 
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paulsmeds said:
The current firmware and data stream provides a mode. But that mode is just 0 for startup mode and 1 for normal operation. To back into the internal alternator working you would have to know what voltage ranges provided in the stream corresponded to ship power vs internal power or if that was even feasible to use as a logic test. Takes less than 10 seconds to a check during runup but it would be nice to have an indicator during flight if the internal failed. If I ever get some time I'll add the voltage to to my screen and see if I can't figure out a correlation.
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I'm with Dan on this one, it screams diode or'd instead of some kind of power controller which would report some sort of status to the microcontroller. I suspect it doesn't have a way to know what's up internally.
 
Mikeyb said:
The other thing about Pmag failure reports to note is how many there are in operation. A recent VAF aborted poll suggested it might be a big number.
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Aborted, meaning? The poll is still active, assuming that's the one you're referring to.
Not a huge number of responses (66 so far), hard to tell what that means with respect to how many are out there but I'm sure that represents only a small fraction.
 
rv6n6r said:
Aborted, meaning? The poll is still active, assuming that's the one you're referring to.
Not a huge number of responses (66 so far), hard to tell what that means with respect to how many are out there but I'm sure that represents only a small
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There was another one asking which ignition system people were using.
 
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rv6n6r said:
Aborted, meaning? The poll is still active, assuming that's the one you're referring to.
Not a huge number of responses (66 so far), hard to tell what that means with respect to how many are out there but I'm sure that represents only a small fraction.
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I find it quite interesting that so many are concerned about the internal generator failing. All magnetoes have internal generators and nobody seems too concerned about that.
 
Norman CYYJ said:
I find it quite interesting that so many are concerned about the internal generator failing. All magnetoes have internal generators and nobody seems too concerned about that.
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Different type of generator and much “softer” failure mode.

…and some of us find the reliability of magnetos “concerning”.
 
I added the "Volt" value that is in the EMAG data stream to my display. Reading lots of different posts it seems you need to add 1 to the value it provides which I did. With that, prior to start just on ship's power the reading is 11.2 even though bus voltage is 12.6. I think this is the board's power reading after some circuitry. Startup stays about the same and then after about 800 RPM it drops a little. Then goes back up. In flight it drops way down to around 7 to 8 but then fluctuates. Once in a while a huge spike in the 30+ range but then right back down - not sure that's real. Long story short, I don't think there is any logical magic in watching the voltage value in the stream to figure if the internal power is running the EMAG or ship's power.

The way I look at it, periodically test it on run up to know it is working. If it stops working in flight then the EMAG automatically works like a regular EI using ship's power. You would be hard pressed to even know it happened. If you are worried about it, test it every flight. Personally I like that it has the internal stand-alone power to run.

I'm not worried about the internal power failing in the slightest. The chances that the internal EMAG power generation fails, the ship's power fails at the same time, and in my case the Slick also fails at the same time are just about 0.00001%. It's on me, the pilot, to make sure systems are operational before flight.
 
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