I'm agree. However depends how clean must be the output. If you need less than say 5mV ripple, then I have doubts the single stage will be ok (at least I've never solved such small ripple in one single stage). On 3/10/07, Chris McSweeny wrote: > You seem to be assuming that the current regulator has to be linear. That's > not the case at all - straightforward to have a switching current regulator, > in which case you don't have a problem with heat. Given 80% efficiency > (which isn't hard to achieve) your maximum power dissipation in the > regulator is only 2W when the output's 10V and 800mA - much simpler than a 2 > stage process. > > On 3/10/07, Vasile Surducan wrote: > > > > 5V and 10V at 800mA is not the same. Keeping dissipation small on > > the current regulator is the key. Definitely I'll vote for an 170VDC > > to 6VDC converter followed by a constant current generator. Power > > dissipation will be maximum (6V-2V)*0.8=3.2W and minimum > > (6V-5V)*0.8A=0.8W. More power at 10V load voltage swing. > > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist