15C LE spike fix

[Jeff O.]

(05-01-2014 09:28 AM)jebem Wrote:  

(04-30-2014 04:59 PM)Jeff O. Wrote:  (...) Adding the capacitor will have no impact on current draw from the batteries during program execution (...)

(...) As soon as the program starts, the capacitor will discharge in a very short time, then the load will be carried solely by the batteries (...)

No offense, but I beg do differ
I would agree with Your first sentence if we were talking about DC current on passive (ie, resistive) loads. But this is not the case (explanation below).

No offense taken. I'm sure you know a lot more than I regarding design of power supplies. However, in looking at Lyuka's plot of current consumption in program run operation (reproduced below), I think I stand by my assertion that a capacitor won't do much to prevent voltage drop during program execution. There is a tiny AC component, but it is mostly DC which must come from the battery. I don't think that a capacitor will have any impact on that. The capacitor does seem to tame the current spikes in other situations.

"Executing tight loop program (10mA / div) : 19mA while executing a program"