Homepage - RF Cafe
Webmaster: Kirt Blattenberger | KB3UON | Sitemap | ©1996-2014
Menu below is just a small sample of what is here!
 
Custom Search
More than 10,000 searchable pages indexed.
•−•  ••−•    −•−•  •−  ••−•  •
RF Cafe Morse Code >Hear It<

Power FET question - RF Cafe Forums

Because of the high maintenance needed to monitor and filter spammers from the RF Cafe Forums, I decided that it would be best to just archive the pages to make all the good information posted in the past available for review. It is unfortunate that the scumbags of the world ruin an otherwise useful venue for people wanting to exchanged useful ideas and views. It seems that the more formal social media like Facebook pretty much dominate this kind of venue anymore anyway, so if you would like to post something on RF Cafe's Facebook page, please do.

Below are all of the forum threads, including all the responses to the original posts.


krc
Post subject: Power FET question Posted: Fri Apr 21, 2006 10:42 pm

Lieutenant

Joined: Fri Apr 21, 2006 10:34 pm
Posts: 3
hi...i am student and this is simple question: i have a power fet that need to be biased at 12 A of current for its Id biasing.however the current source outputs 25 A of current. since i don't have resistor that can handle this level of current what can i do so that only 12 A of current goes in the drain of the current? thanx

kc


Top

IR
Post subject: Posted: Mon Apr 24, 2006 4:07 pm

Site Admin


Joined: Mon Jun 27, 2005 2:02 pm
Posts: 373
Location: Germany
Hello,

The current passing through the FET's drain is set by the minimal load that you will connect to your circuit. There are many current limiting circuits relatively easy to implement, and you need to use one in your design. Look in Google there are many applications for such circuits.

Here is just a single example from a quick search in Google:

http://www.radio-electronics.com/info/c ... imiter.php


Good luck!

_________________
Best regards,

- IR


Top

Jeanalmira
Post subject: Posted: Tue Jun 13, 2006 10:21 pm

General


Joined: Tue Mar 15, 2005 11:43 pm
Posts: 65
Location: Singapore
Hi krc :

I agree with IR.
Antoher way to control the drain current, you also may want to limit/set your gate biasing voltage, so that it will give you the desired drain current at respective drain voltage. For doing this, you can try to apply voltage divider in the gate bias line.

I hope it helps.

Cheers,
Jean







Posted  11/12/2012
A Disruptive Web Presence

Custom Search
Over 10,000 pages indexed! (none duped or pirated)

Read About RF Cafe
Webmaster: Kirt Blattenberger
    KB3UON

RF Cafe Software

RF Cascade Workbook
RF Cascade Workbook is a very extensive system cascaded component Excel workbook that includes the standard Gain, NF, IP2, IP3, Psat calculations, input & output VSWR, noise BW, min/max tolerance, DC power cauculations, graphing of all RF parameters, and has a graphical block diagram tool. An extensive User's Guide is also included. - Only $35.
RF system analysis including
frequency conversion & filters

RF & EE Symbols Word
RF Stencils for Visio

Product & Service Directory
Personally Selected Manufacturers
RF Cafe T-Shirts & Mugs

RF Cafe Software

Calculator Workbook
RF Workbench
Smith Chart™ for Visio
Smith Chart™ for Excel
Your RF Cafe Progenitor & Webmaster
Click here to read about RF CafeKirt Blattenberger... single-handedly redefining what an
                                 engineering website should be.

View the YouTube RF Cafe Intro Video Carpe Diem! (Seize the Day!)

5CCG (5th MOB): My USAF radar shop

Airplanes and Rockets: My personal hobby website

Equine Kingdom: My daughter Sally's horse riding website