DIY Fan Speed Control

[reefburnaby]

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 ]