On Tue, 16 Oct 2007 13:21:48 -0000, "
wrote:


Thanks but the problem with the 317T and also the L200 is R=1.25/I
Fine for a fixed current but hard to achieve a variable one.- Hide quoted text -

Due to the low value R not available as a variable one? How many
different currents do you want? Just switch in different resistors.


Yes that's how I do it now with fixed value resistors
But I would like to build a completely variable supply as per the
original post !


Alternatively use a simple transistor as a current source.

MBQ

Great can you point me to a circuit that works and I can build.
Electronics is just a diy hobby I am not a design engineer.