Tony Nixon wrote: > >You're right, I only catered for about 470uF at present, but the PCB is >still 'open' for awhile yet. I figured what I learnt at electronics >school - 1000uF / amp (ball park). > >The final product will have the right choice and there is room for a >bigger cap. > Obviously wasn't too clear to me exactly what was up, as I was only looking at an unlabelled pcb layout. The cap spacing looked smaller - but then I wasn't really sure which were the caps - [Olin's right - see what happens when you don't include "all" the comments - he, he] :-). Let's see --- I/C = dv/dt --> 1A/1000uF = 1000v/sec --> 1v/msec --> 20v/20msec, where 20msec = period of 50hz AC [Check my math - it's too early in the morning]. It says, if you suck 1A out of a 1000uF cap over the period of your AC input, then Vcap will drop 20v. Yes? - dan -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu