Patent ID: 7130248
Filing Date: 2006-10-31
Classification: H02J

Abstract:
1. A real time clock charging circuit mounted on a circuit board and adapted to charge a real time clock being electrically connected thereto, comprising: a booting power input terminal adapted to receive an booting power; a power storage unit adapted to receive and store said booting power from said booting power input terminal and to output a spare power when the real time clock charging circuit receives no input power from the outside; a first control module electrically connected between said booting power input terminal and said power storage unit and adapted to prohibit said spare power from flowing into said booting power input terminal; a standby power input terminal adapted to receive a standby power from an external standby power source when said booting power input terminal receives no input power; and a second control module electrically connected to said first control module, said power storage unit and said standby power input terminal to prohibit said booting power and said spare power from flowing into said booting power input terminal and to prohibit said standby power from flowing into said first control module and said power storage unit, and to receive said booting power, said spare power and said standby power respectively, and to output said booting power, said standby power and said spare power to said real time clock.