View Single Post
  #1  
Old 04-02-2002, 12:27 AM
reefburnaby reefburnaby is offline
Member
 
Join Date: Aug 2001
Location: Burnaby, B.C.
Posts: 766
reefburnaby is on a distinguished road
Default DIY Fan Speed Control

Hi,

As for the 2N2222/PN2222A thingy...I think I(ce) of 400mA is pushing it. Usually, you'll need a aluminum heat sink cap for the 2N2222 to achieve its maximum rating (which happens to be 500mA).
Switching motors (reactive loads) is fairly rough on the electronic switches. It is best to overdesign these circuits. 2N2222/PN2222A are designed to supply 500mA - I would try to keep it below 250mA.

Most bipolar transistors have a beta of 40 or higher.

- Victor.

[ 01 April 2002, 20:59: Message edited by: reefburnaby ]
Reply With Quote