fechter wrote:I'm not sure how useful the HVC input is. It would save some stuff if it was left out.
I'm also not sure if it needs a manual restart. Normally it should not need it if the voltages are dialed in right, but could be used to 'top off' a nearly full pack.
As with the mini-limiter, the HVC input does offer some options from external cell-level monitoring - so seems valuable and can be left unpopulated if not desired.
I think the only question is the desired behavior of that external input. Just playing Devil's Advocate here - if the external input did not latch, then when the external alarm was removed, charging would resume until the internal cutoffs bought charging to conclusion normally or until the alarm re-asserted. This might cycle in and out of alarm a while until all the cells became charged enough to trip the internal cutoff. If this doesn't seem like objectionable behavior then removing the HVC latch could be good. If so:
(I'm kind of rushing this out, but I think this is correct
It seems the latching effect as it relates to the HVC input is tied in part to the response time of the MW in comparison to the voltage drop at the collector of Q. If a bit of damping is introduced with a small RC hung from U2b to Gnd (across R11+R8), then when HVC goes high, the voltage at the Q collector will fall more slowly presenting a declining voltage to U2 indicating a declining 'apparent' current. The apparent current will seem very high initially in the limiter zone, drop into the middle no-limiter range, and finally fall to the float cutoff level. A true pack current higher than cutoff will prematurely terminate this decline with a voltage across R8, allowing normal charging to resume. The RC constant should only need to be large enough to safely allow the MW response to outrun the voltage decline across the no-limiter voltage zone and should not materially affect normal operation.
A side effect of this modification is that a manual reset could be accomplished with a pushbutton from HVC to Gnd. (Another way to look at this is that manual reset takes an additional RC, and by the way, the HVC works a little differently....)