Single transistor constant current power led driver.

Other Hardware LEDs and Multiplexing
13

Erni:
I use a BC337 and to LED's on basis

Are these values as expected ?
I was hoping for a constant current independent of voltage to drive my 1W LED's

One Watt?

You probably need a lower value resistor between 'drive' and 'base' or the transistor can't turn fully on.