According to Sean Breheny on Wed, 01/23/13 at 11:03: > > One thing that comes to mind is that it may rely on a certain range of > battery internal impedance to work properly. Either it wants to pull > high current pulses from the battery and can't do that from your > wall-wart, OR, the wall-wart voltage stays high at higher currents > than the batteries do and there is no current limiting action that you > would have with the batteries. For example, I've seen LED flashlights > which have no current limiting other than the battery internal > resistance. If you run them on a PS that can source more current they > blow out the LEDs. Wow! Thanks. That is _very_ interesting and, indeed, could explain what is going on. In my terms, the switching wall wart isn't very "deep" like a linear supply might be for a similar rating. If this is the case, simply sticking a large capacitor across the +/- supply would not help. Similarly, replacing the switching wall wart with a linear version would not help (if the "blow out the LEDs" risk is present). Darn! This is discouraging... :-( Regards, web... --=20 William Bulley Email: web@umich.edu 72 characters width template ----------------------------------------->| --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .