mmmmmm well it is nice to see you want to jump in at the deep end. Not knowing your electronics background I will attempt to do this through analogy.Originally posted by vinayak@Mar 12 2006, 07:04 PM
what is meant by fet-(field effect transistor)
That's a good analogy.Originally posted by windoze killa@Mar 12 2006, 09:51 AM
....A FET on the other hand uses the voltage on the gate of the FET control the drain current. It does this by "pinching" of the current flow from source to drain. If you consider a FET to be a hose with a variable clamp around it. As you tighten the clamp less water will flow.....
WOW Thanks for the praise guys. I was just trying to make it simple. After teaching RF comms and multi layer PCB repair for 8 years I found that you can throw all the maths and theory you lke at a student but if you don't bring it down to their level they will never learn. Also it was technicians I was teaching and not engineers so there were no PHDs involved.Originally posted by Dave@Mar 13 2006, 12:35 AM
In addition to the superb answer provided by windoze killa, you may wish to refer to The Art of Electronics by Horowitz and Hill which will give you a comprehensive overview of FETs (both MOSFETs and JFETs) without the excessive mathematical baggage that comes with learning about these devices.
AAC: Volume III deals with semiconductor devices that will explain in more detail about FETs. There is a lot of content in this section so you are best asking questions about sections you may not be familiar with here in the forums.
The University obsession of throwing every possible equation at students is what makes the subject of electronics more difficult than it needs to be; equations are alright when a student grasps the concept, however its tends to be the case that Universities wish to make a student know the equation before (and sometimes at the expense of) the concept. Also there seems to be too much emphasis in Universities on derivation of equations - all this tests is can you remember a sequence of instructions.Originally posted by Hurdy@Mar 13 2006, 07:14 PM
windoze killa you should come and teach at my uni! These formulas they through at us really makes things confusing
A lot of the lecturers tend not to lay good foundations down and rather jump straight into a lot of maths etc. They need to explain more on how these components work, so it will allow us to understand the formulas a lot easier. If you don't understand what is supposed to happen, the formulas just become useless numbers.
It is unfortunate that there are poor teachers in all subjects, and many authors who make a living from it. I recall going on a management course many years ago and being asked to study a chapter on the subject of communication in Peter Druckers book The Practice of Management. It spanned about five pages and was full of what I call nebulous waffle or modern management-speak. I had to re-read it three times before I understood what he was saying - it was that you should keep communications simple! I was quite surprised that my company was taken in by such drivel!Originally posted by Dave@Mar 13 2006, 08:07 PM
The University obsession of throwing every possible equation at students is what makes the subject of electronics more difficult than it needs to be; equations are alright when a student grasps the concept, however its tends to be the case that Universities wish to make a student know the equation before (and sometimes at the expense of) the concept. Also there seems to be too much emphasis in Universities on derivation of equations - all this tests is can you remember a sequence of instructions.
As for PhD's, my experience of working with people of such status has not always been a positive one, but then that's another story!
Well Dave, it is the same here in Oz. We have to pay a fortune to go to Uni and the government have to suck there fees out of us to. But I tricked them. I never went to Uni. I did all my training in the defence forces which is also where I did my teaching.Originally posted by Dave@Mar 15 2006, 01:26 AM
You make an interesting point pebe, about the poor quality of teachers/lecturers. This is an inherent problem, even in the world's highest educational institutes. The sad fact is that many educational institutes are more interested in getting "bums-on-seats" to get the income from governments (this is certainly the case here in the UK).
This is also related to universities in the UK now expecting all students to pay tuition fees and take out loans to pay for their education, whatever happen to investment in our future. On a side matter the problem with people studying for postgraduate qualifications, e.g. PhD and MSc, is that they pay good money (anything up to 10's of thousands of pounds) to study for the qualification - as far as the University is concerned this is the key factor; this means that the only route to postgraduate qualification level is to be born into a financial situation that allows for it. As a result, you tend to get a mono-type of people in the higher levels of engineering education, where their only experience of engineering is in solving equations and studying theories. Not to mention that someone who is from a poorer background, who incidentally could be smarter than any of their peers, would not be able to work towards these postgraduate qualifications, due to their background.
I can't comment on what its like in other parts of the world, and we may get it easy here in the UK, but I have fundamental issues with the education system. That said I'm a by-product of the very system I have problems with!!
At least you are staying in the better part of the UK!! All this London lark is no good for the visiting national. Be sure to take a look at our fantastic engineering heritage in Manchester, particularly go and see the Manchester Museum of Science and Industry should you get the opportunity.Originally posted by windoze killa@Mar 15 2006, 10:35 AM
And to all you Pomgolians over there in the mother land, I should be over there for a few weeks around June. Will be staying near Manchester.
I was there for about 3 weeks last year and hardly saw Manchester at all. Did the tourist thing over Middlesborough and Newcastle. Absolutely love the scenery and history. Durham was amazing.Originally posted by Dave@Mar 18 2006, 11:10 AM
At least you are staying in the better part of the UK!! All this London lark is no good for the visiting national. Be sure to take a look at our fantastic engineering heritage in Manchester, particularly go and see the Manchester Museum of Science and Industry should you get the opportunity.
Aye "Geordieland" is quite a place. The Geordies are great people, if a little difficult to understand!Originally posted by windoze killa@Mar 18 2006, 09:31 AM
I was there for about 3 weeks last year and hardly saw Manchester at all. Did the tourist thing over Middlesborough and Newcastle. Absolutely love the scenery and history. Durham was amazing.
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