You never waste volatge with pwm charging? That's the point. Either there is 0 current through and 12v over your FET, or there is lots of current through and close to 0v over it. Result in both cases is very little power dissapation. What you *don't* want is soft slopes on the switching between on and off. That would make it heat up a lot. KreAture ----- Original Message ----- From: "Diego Sierra" To: Sent: Tuesday, September 23, 2003 8:53 PM Subject: Re: [EE:] NiMH charger improvement > On Tue, 23 Sep 2003 08:21:31 -0700, John Ferrell > wrote: > > > find that often the charger s unable to detect the peak, especially with > > NiMh. It is desirable to have a step down to trickle after a certain > > John, thanks for the advice, but I managed to make my charger works :-) > > What I want is to use a switching power suply for powering the charger, but > with a voltage output controlled with the PIC depending on the number of > batteries to charge, i.e., for just 1 battery a 3v output is enough, but > for 4 batteries I would need 9v, I do not want to have a fixed 12v output, > because when the 1 battery charge, I waste 9v. > > The other thing is to charge different batteries in serie, disconnecting > them while they get charged. > > Cheers, > Diego. > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu