A capacitor charging circuit and method including a plurality of serially connected
capacitors and parallel monitor circuits connected in parallel on a one-to-one
basis to the capacitors. Each one of parallel monitor circuits applies a direct-current
source voltage to a capacitor and bypasses a charge current of the capacitor when
the charge voltage of the capacitor exceeds a reference voltage. Each of the parallel
monitor circuits includes a reference voltage circuit, a voltage detecting circuit,
a comparator, a bypass switching circuit, and a voltage limiter. The reference
voltage circuit generates the reference voltage. The voltage detecting circuit
detects the charge voltage of the capacitor. The comparator compares the reference
voltage with an output voltage from the voltage detecting circuit and controls
the bypass switching circuit to bypass the charge voltage using the voltage limiter
to limit a voltage applied to the bypass switching circuit.