I'm working on building a charger for a 22.2V pack i made with six 18650 cells from a laptop battery back wired in series.
Im considering active balancing by using the shared transformer method, see fig 7 in this pdf: http://users.utcluj.ro/~atn/papers/ATN_2_2010_1.pdf
I'm thinking a 30 turn primary and six 5 turn secondaries as that would turn the full pack voltage into the correct voltages for each cell.
The part i don't quite understand in that pdf is that the secondaries are wired the wrong way, the diode is facing the negative pole rather than the positive pole.
Is this a drawing error or does that reverse current act like the passive shunt balaner by using a reverse current over the cell to divert the charger current to the other cells ?
And i imagine the box that sez "control" is more or less just a 50% duty cycle clock that gets an enable signal from the charger.
Im considering active balancing by using the shared transformer method, see fig 7 in this pdf: http://users.utcluj.ro/~atn/papers/ATN_2_2010_1.pdf
I'm thinking a 30 turn primary and six 5 turn secondaries as that would turn the full pack voltage into the correct voltages for each cell.
The part i don't quite understand in that pdf is that the secondaries are wired the wrong way, the diode is facing the negative pole rather than the positive pole.
Is this a drawing error or does that reverse current act like the passive shunt balaner by using a reverse current over the cell to divert the charger current to the other cells ?
And i imagine the box that sez "control" is more or less just a 50% duty cycle clock that gets an enable signal from the charger.