Fly Lah!

GreAse-M0nk3y wrote:hi there..

i got one question that i want to be asking here...FYI,i got the bridging junior technician for MAS and i will joining them on this 2nd august..so i want to ask, what will they conduct for the bridging junior technician class?is it for familiarization class?

i am not sure whether yes or not your question should be answered in this thread, because we have been discussing topic related to a/c systems since the 1st post.

-- Mon Sep 20, 2010 1:25 am --

rather boring because it seems like nobody want to raise question about aircraft anymore?

I guess not many drop in and participate, mostly would rather read than contribute?

or because during most of time there are only 5 people online and only 2 of them are registered users and the remaining are guests?... plus one of the registered users is a moderator?

That too, I guess..

refusetakeoff wrote:hi there....
new question
what the diffrence between DC ground n AC ground?

physically i see it as the same....

Somehow I find out that this topic regarding AC and DC ground is somewhat like 'hang up'... I have reviewed the answers to this question but it is not convincing in the way they are explained.

As we know it has been that the Ground for aircraft electrical system is also a current 'Return' path.

I am told by an avionic engineer that the DC and AC ground are 'sharing' the same ground- hence the same aircraft metal structure. BUT... there is the BUT ... they DON'T...because they are connected on different terminal, though both terminal are connected to the same aircraft body.. this is what i understand. or maybe I just miss some parts.

like a heating system that gets it's power from an AC BUSBAR and a DC motor gets it's power from a DC BUSBAR... but still their current path is the same aircraft structure.

but for a solid state components - electronic wise, they are sensitive to high heat and high voltage and easy to get damaged - they got their power from device like TRU or INVERTERS .. so that their return path wont be an aircraft structure. AM I RIGHT UNTIL THIS POINT?

don't forget to correct my understanding if there is mistake.

You're definitely not avionics trade material!

torx wrote:You're definitely not avionics trade material!

pls be straight to the point lah torx .. i want your idea on this.. mybe the way i understand something and the way i explain thing does not suit others...

i know a lot of things i have to learn about electrical systems...

What have you covered as far as 'Electricity' is concerned?

torx wrote:What have you covered as far as 'Electricity' is concerned?

Ohm Law, v= IR
Kirchhoff Law- Current and voltage law.


Electricity- we create a potential different between two terminals so that current will flow between them.

to make a current flowing we pass them through a conductor with potential different (voltage) exists.
to stop a current flowing we break the conductor.
to seal a flowing current we do it with insulator so that it does not short circuit.


i remember one thing in an electrical diagram, the ground for DC and AC is drawn to be the same and nothing in the note explaining about this..that's one of thing that lead me to confusing although I went through the airframe electrical system MCOQ test. MCOQ.... that makes me worry even if I made it to 90% and above.

for ac or dc busbar its only the power supply for the system...
either 1 need to be grounded...but my question is why if both ac n dc need to ground to a/c body but they used diffrent ground point... i think i already got the answer but forgot pulak...
i'll ask around again and will post it here...