A battery charger with a discrete switched regulator provides relatively
high efficiency and relatively low cost. Unlike known battery chargers
which incorporate switched regulator ICs, the battery charger in
accordance with the present invention utilizes the microprocessor for a
dual function. In particular, the microprocessor not only controls the
charging characteristics of the battery charging circuit but also
directly controls the power output of the battery charger by direct
control of the discrete switched regulator circuit. By using a discrete
switched regulator circuit and redefining the role of the microprocessor,
the battery charger in accordance with the present invention is
relatively less expensive than known battery chargers which incorporate
switched regulator ICs.