The “hehe” meant “I sympathize with you”.



eh?

How do you know I won’t try at all?, I've got 30 questions, and I've been thinking over and over since last Thursday when they handed me these questions. And believe it or not my first answer for the third one was “DC voltage source”, but then I doubt, I hardly ask for help, and I know a voltage source keeps a constant in voltage across its terminals, like a battery for example, but since is a source of voltage (maybe I’m wrong with this) and therefore current, I wasn't really sure if the current was proportional to the voltage of it, and I really don’t know how current works or runs inside a voltage source.

I’m still not sure about the last one though, since it can be a capacitor or a semiconductor as I pointed out, (I said electrolyte thinking about an electrolytic capacitor.)

Capacitor:

metal foil (conductor)

dielectric (non-conductor)

metal foil (conductor)

Semiconductor:

P-type (conductor)

PN-Junction (non-conductor)

N-type (conductor)

my native language is no English, sorry.

A suggestion:

Don't just rely on the information given in your course,or the text specified.
Go to your local,or even better,main city library,& look at alternate texts.

Sometimes,you need the extra bit of information,or a better explanation.

If your local University is having a book sale,browse through it,you may pick up some great Electronics texts for very little.

There are some very learned people on this forum,(not me,----the others),but even they find it hard to always give an answer which will"sink in",given the limitations of a single posting.

 

Varicaps,any one?

And your point?

Notice that I very specifically did NOT say that this is NEVER why junctions are made. What fraction of PN junctions are varicaps or other devices in which the point of the design was to exploit the junction capacitance? My guess is that one in a thousand would be a hugely generous estimate and that one in a million might not be too stingy.

 

In addition to your local and school libraries, other great place to look is Amazon (and there are others as well, I just happen to go to Amazon first). The Amazon Marketplace (although I don't know if they still call it that, because it is pretty tightly integrated with the normal Amazon website) allows third-party sellers to list and process payments through Amazon. There is a flat $3.99 shipping fee (at least in the continental U.S.) and very often you can find textbooks there for $0.01. For what you are doing, there are LOTS of textbooks that are a few editions old that basically have no market value. People buy estates for next-to-nothing (or are even paid to haul the stuff away) and they just want to MOVE things fast. They don't even attempt to find out if a book might have any value, they just ship it the cheapest way they can and pocket the difference.

 

And your point?

Notice that I very specifically did NOT say that this is NEVER why junctions are made. What fraction of PN junctions are varicaps or other devices in which the point of the design was to exploit the junction capacitance? My guess is that one in a thousand would be a hugely generous estimate and that one in a million might not be too stingy.

Well,mainly I was just rattling your cage!

I do agree that the vast majority of such junctions are not for varicaps,but in fact,there are many millions of such devices in use
in PLLs throughout the world.