| 摘要 |
An automatic battery charging circuit for emergency illumination, comprising a resistor R1, a resistor R2, a diode D1, a control chip, a triode Q1, a resistor R12, a resistor R4 and a high-precision reference source chip U1, wherein one end of the resistor R1 is connected to a positive electrode of a battery, the other end of the resistor R1 is respectively connected to one end of the resistor R2 and an anode of the diode D1, the other end of the resistor R2 is grounded, a cathode of the diode D1 is connected to an input end of the control chip, an output end of the control chip is connected to a base electrode of the triode Q1, a collector electrode of the triode Q1 is connected to the positive electrode of the battery, an emitting electrode of the triode Q1 is connected to one end of the resistor R12, the other end of the resistor R12 is connected to one end of the resistor R4, the other end of the resistor R4 is connected to a cathode of the high-precision reference source chip U1, and an anode of the high-precision reference source chip U1 is grounded. The automatic battery charging circuit has low cost, can automatically charge a battery and can automatically cut off the charging after the charging is completed. |
