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The main struggle I'm having with the material provided to pass the exam is with basic electrical theory. I got stuck on the chaper that covers inductance, capacitance, reactance, Q, and related topics. After that the whole book looks like a breeze, including the electromagnetic RF theory.
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Quote:...that covers inductance, capacitance, reactance, Q, and related topics.....
They are all concepts buddy. Not very difficult to understand =P
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Perhaps easy for you to say, but not all of us share your immediate correct sense of electrical concepts.
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Zack, what are you stuck with exactly? Im sure a lot of us could help you out.
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shutup.
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Well, a question that, if answered, could help me out is this:
I don't understand how more than one capacitor in series is effective. Because there is ideally no transfer of electrons through the dielectric in a capacitor, then there would be no potential difference across the dielectric, and hence no electrical field, and hence no capacitance.
Here's a diagram. The stuff in brown is not part of the schematic, but rather notes.
![[Image: 1eq43o]](http://tinypic.com/1eq43o)
So, to sum up, how does any capacitance remain in a circuit containing more than one capacitor in series?
(BTW, I'm talking about DC here, although I'm not sure if it matters).
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A wild guess, based on knowledge (but none about capacitors)
-||---||-
- e-> +
Even if it's no real current between the capacitors, there are still electrons
in the material they're made of, and they do wander because of
the electrical field.
That is a possible answer...
/post]
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OK from Howstuffworks.com
Quote:A capacitor can block DC voltage. If you hook a small capacitor to a battery, then no current will flow between the poles of the battery once the capacitor charges (which is instantaneous if the capacitor is small). However, any alternating current (AC) signal flows through a capacitor unimpeded. That's because the capacitor will charge and discharge as the alternating current fluctuates, making it appear that the alternating current is flowing.
so I think:
Electricity goes through one capacitor, charges up a little, goes to next capacitor charges up little. but with DC this keeps going on until the first one is filled and blocks the current.
it may also depend on the capacitor....
EDIT: I didn't really read the whole thing. Just so you know I could be wrong.
![[Image: sig.php]](http://josh.whtiger.net/images/sig.php)
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Quote:A wild guess, based on knowledge (but none about capacitors)
-||---||-
- e-> +
Even if it's no real current between the capacitors, there are still electrons
in the material they're made of, and they do wander because of
the electrical field.
That is a possible answer...
Could be the case, but wouldn't that just induce current, and not the required potential difference between the plates of the capacitor?
Quote:OK from Howstuffworks.com
Quote:A capacitor can block DC voltage. If you hook a small capacitor to a battery, then no current will flow between the poles of the battery once the capacitor charges (which is instantaneous if the capacitor is small). However, any alternating current (AC) signal flows through a capacitor unimpeded. That's because the capacitor will charge and discharge as the alternating current fluctuates, making it appear that the alternating current is flowing.
so I think:
Electricity goes through one capacitor, charges up a little, goes to next capacitor charges up little. but with DC this keeps going on until the first one is filled and blocks the current.
it may also depend on the capacitor....
EDIT: I didn't really read the whole thing. Just so you know I could be wrong.
Yeah, but like the howstuffworks article you quoted said, if the capacitor is small then it will be charged instantaneously. And also, as far as I can see, a capacitor can only be charged with a potential difference between the plates, and in series, there is potential difference, but not with only a single dielectric in between - with two whole capacitors in between!
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Going for my technician liscence next month. All I can say is go for it. Amatuer Radio is an exceptionaly cool hobby.
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Well, I took the Industry Canada mock exams a bunch of times(they're actually the real exams, except I get no certification if pass), and got at least 60% (my lowest =62, highest=80). So I guess I'm ready for the real thing, and I even have my eye on a beautiful handheld, the Icom T90A. It's a 5 watt tri-band, can transmit on the 2m, 6m and 70cm bands, and can recieve 495kHz to 999.990MHz, so that means I can listen to ANYTHING - radio stations, shortwave commmerical broadcasts, police radio, CB, anything. It even will let you listen to the audio of TV stations!
http://www.icomcanada.com/products/amate...a/t90a.htm
Check it out. It's a beauty. I can get it for $350 CDN.
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