| 摘要 |
PURPOSE:To suppress temperature rise of a charging current control transistor by interrupting charging current even upon application of abnormal voltage due to incorrect use. CONSTITUTION:The charging circuit controls the voltage across a charging current setting resistor to be equal to a reference voltage 11 by feeding a current proportional to that of a charging current control transistor Q1 to the charging current setting resistor. When the input voltage Vi increases abnormally, the charging current control transistor Q1 is heated intensely but a thermally coupled thermal shut circuit 12 lowers the reference voltage 11 and lowers the charging current Ia thus suppressing temperature rise of the charging current control transistor Q1. |
