Switch on/off position!?

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Bundy
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Re: Switch on/off position!?

Postby Bundy » Thu Jan 17, 2013 4:45 pm

D2O wrote:
KlapperKnop wrote:When a switch is open circuit, is that off or on? Depending what logic is applied; assume positive logic. Open circuit even in electrical is an off condition. When a MAG is off, the switch is on an ON condition causing a short circuit. In my aerie and the schools tikes I have flown, when the MAG was on, the switch was in a down position (OPEN CIRCUIT) and the panel read ON.
Ok, that's just confusing (**) :lol:
With an electronics background, I can safely say that an off switch is ALWAYS open circuit, or am I missing your point completely?
Think carefully Noel....what does the mag switch do when it's in the "off" position.....it earths! (IE Closed circuit)
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D2O
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Re: Switch on/off position!?

Postby D2O » Thu Jan 17, 2013 5:25 pm

Bundy wrote:
D2O wrote:
KlapperKnop wrote:When a switch is open circuit, is that off or on? Depending what logic is applied; assume positive logic. Open circuit even in electrical is an off condition. When a MAG is off, the switch is on an ON condition causing a short circuit. In my aerie and the schools tikes I have flown, when the MAG was on, the switch was in a down position (OPEN CIRCUIT) and the panel read ON.
Ok, that's just confusing (**) :lol:
With an electronics background, I can safely say that an off switch is ALWAYS open circuit, or am I missing your point completely?
Think carefully Noel....what does the mag switch do when it's in the "off" position.....it earths! (IE Closed circuit)
Aaaah, I get what you're saying now :oops:
Not good reasoning for orientation of "OFF" and "ON" positioning though. Thhere should be no confusion as to what the word "OFF" on a switch in the cockpit means. Regardless of how it's wired, "OFF" to a pilot must mean the mag is off,i.e. the engine is OFF and if you put both switches there, you kiss the earth very quickly :lol:
At the end of the day, as long as it is clearly marked, there is no law that says you can't have it either way. Standardisation is key though.
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KlapperKnop
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Re: Switch on/off position!?

Postby KlapperKnop » Thu Jan 17, 2013 6:32 pm

Noel, there is actually no confusion as the ON/OFF state is reference to the MAGNETO. You must have heard Alex/Henri/Marius always saying MAG OFF --- MAG ON ... these condition were never reference to the switch. When the MAG is ON (NORMAL) the switch is OPEN CIRCUIT (OFF) and when MAG is OFF, the switch ON (SHORT CIRCUIT, EARTHED)
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mulderpm
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Re: Switch on/off position!?

Postby mulderpm » Fri Jan 18, 2013 8:38 am

Bundy wrote:then as long as the PIC knows,

Yip, and for Mr Mulder that was not always the case. ## On one cabbage patch sortie we aborted a landing at JAG due to cows on the runway and diverted to A4 (mistake) ## near Cullinan. I switched off the mags but the engine did not stop. :shock: Used the choke to kill the engine. After some coffee and wing wiggling, tyre kicking and talking k@@@k we were ready to leave. Now the problem starts...which way is mags on....because she runs in either position, up or down. :? The only difference is in one position she runs on one mag and the other on both. Needless to say, I made the wrong decision, and flew back on one mag. :oops: That is why I now have the acronym.... down is on. Labels may be the better option. :?:
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