Re: simple switcher constant current supply with high side sense resistor

From: Tony Williams (tonyw_at_ledelec.demon.co.uk)
Date: 02/05/05 

Date: Sat, 05 Feb 2005 09:15:37 +0000 (GMT)

In article <uZRS$5B2meACFAm8@tega.co.uk>,
   Tim Mitchell <timng@sabretechnology.co.uk> wrote:
> I'm trying to design a simple switcher constant current circuit
> (using the LM2574-ADJ). It's easy enough if you put the sense
> resistor between the load and ground. However the snag is that
> the current sense resistor has to be on the high side of the
> load (there are 3 current supplies driving 3 devices with a
> commoned ground).

 Sideways thought.....

 If a flyback converter is arranged to dump a fixed
 Joules/cycle, then making the Frequency proportional
 to Vout should result in a constant Iout. 

-- 
Tony Williams.