Post by RoMan MandziejewiczA skąd wniosek, że flyback ma małą sprawność?
nie mowilem, ze ma mala
tylko, ze ma mniejsza niz buck czy boost;
--- Flyback versus Buck or Boost ----
To illustrate the flyback configuration's poor efficiency, compare it with
the more favored buck and boost topologies. The flyback circuit's main
problem is high peak current, which produces high I2R loss. Peak currents
cause dissipation in small parasitic resistances: series resistance in the
inductor, on-resistance in the switch, and ESR (equivalent series
resistance) in the filter capacitor.
These losses are proportional to the peak current squared, so a minor change
in peak current can have a substantial effect on conversion efficiency and
battery life. In the four-cell application, physics ensures that a flyback
circuit's peak currents are almost double those of a buck or boost circuit.
It is intuitive that peak currents in the buck and boost topologies should
be lower. Because the series connection of a boost regulator's battery and
inductor aids the inductor-discharge voltage, the boost circuit needs to
overcome a smaller energy "hill" in generating the output voltage. Peak
currents in the buck regulator are lower, too, because current flows to the
load during both the charge and discharge phases of the switching cycle.
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