BATTERY CHARGER AND CURRENT CONTROL DEVICE

To reduce a current rating value of a switching element while coping with a connected load increase.SOLUTION: A battery charger includes: a generator which generates power according to the rotation of a rotor to output an AC signal corresponding to the generated power; a switching element which rectifies the AC signal output from the power generator to supply to a battery as charge power; a positive/negative change determination unit which determines a change of the positive and negative voltages of the AC signal; a trigger output unit which, based on the determination result of the positive/negative change determination unit, outputs a trigger signal which indicates the conduction timing of the switching element; and a positive/negative determination control unit which, by detecting the voltage of the AC signal, detects the revolution speed of the rotor, and if the detected revolution speed becomes a predetermined threshold or higher, controls the positive/negative change determination unit to additionally maintain the determination of the negative voltage of the AC signal for a predetermined period.SELECTED DRAWING: Figure 1 【課題】接続される負荷の増大に対応させつつ、スイッチング素子の電流定格値を低減する。【解決手段】バッテリ充電装置は、回転子の回転に応じて発電し、発電した電力に応じた交流信号を出力する発電機と、前記発電機が出力する前記交流信号を整流して充電電力としてバッテリに供給するスイッチング素子と、前記交流信号の正負電圧の切り替えを判定する正負切替判定部と、前記正負切替判定部の判定結果に基づいて、前記スイッチング素子の導通タイミングを示すトリガ信号を出力するトリガ出力部と、前記交流信号の電圧を検出することで、前記回転子の回転数を検出し、検出した前記回転数が所定の閾値以上になった場合に、前記正負切替判定部に、前記交流信号の負電圧の判定を、所定の期間、追加で維持させる正負判定制御部とを備える。【選択図】図１