Below mention simple circuit can used as a dimmer in DC range ,
from 0 to 20 VDC, here a powerful FET were used to deliver much DC
Amperes for the appliances ,this Circuit can be easily understand where
here we used only three basic (3) parts ,FET gate were kept biased between +VE & -VE supply, 100 k were
attached between gate & positive supply, on the other side a variable resistor
( 500 K ) were used ,as we know FET behave like a latched on nature , once Gate
activated it will remain on until power to the whole circuit disconnected ,
this issue here can be settle by biasing gate with negative power supply , once
FET off due to –VE biasing , it can be easily on by varying biasing between +VE
supply , now here 500k can control the output from the drain , output may be a DC fan , DC
LED light , IRFP064N FET is a favorite choice for the normal use , but a good
heat sink will be required for the FET to tolerate in high power mode,
