What is a Mosfet device ? is it variable rate relay?

[e-bumby]

What is a Mosfet

Ok I know if you apply voltage to it and a drain, then add a small voltage to the gate it powers the drain with the higher voltage/current right...

And it goes up and down as the low voltage is applied right...

So a Mosfet is just a variable rate relay then... right ?

 

[Tahmid]

What is a Mosfet

NO, A MOSFET is a switch which is controlled by the gate.
Read this (Basics of MOSFETs):

www.irf.com/technical-info/appnotes/mosfet.pdf
[url]www.fairchildsemi.com/an/AN/AN-9010.pdf[/url]
[url]www.national.com/an/AN/AN-558.pdf[/url]
en.wikipedia.org/wiki/MOSFET
en.wikipedia.org/wiki/Power_MOSFET
[url]http://www-g.eng.cam.ac.uk/mmg/teaching/linearcircuits/mosfet.html[/url]

Hope this helps.
Tahmid.

 

[e-bumby]

Re: What is a Mosfet

NO, A MOSFET is a switch which is controlled by the gate.

Tahmid.

Yes I know its a switch but I thought it was more than and on/off switch and the output to the drain changes as the gate signal changes ?

 

[keith1200rs]

Re: What is a Mosfet

NO, A MOSFET is a switch which is controlled by the gate.

Tahmid.

Yes I know its a switch but I thought it was more than and on/off switch and the output to the drain changes as the gate signal changes ?

You are correct - it is not simply a switch. It can be used as a switch but is can also be use as a more 'progressive' switch depending on what you allow the drain voltage/current to do (which depends on the load).

Keith

 

[neils_arm_strong]

What is a Mosfet

e-bumby you are right. It is a variable rate relay.