Battery charging system including means for distinguishing between rechargeable and non-rechargeable batteries
High frequency switching battery charger
Auto-start and magnetic shut down battery charging and surveillance circuits
Battery charger termination circuit
Battery charger with three different charging rates
Controller for battery charger
Microprocessor controlled battery charger Patent #: 5013992
ApplicationNo. 034175 filed on 03/18/1993
US Classes:320/160Multi-rate charging (e.g., plural charge rates before a maintenance charge, etc.)
ExaminersPrimary: Stephan, Steven L.
Attorney, Agent or Firm
International ClassH02K 007/04
AbstractA battery charger including a battery detector at a node at which a battery is connectable. When a battery is not present, a voltage at the node fluctuates, but when a battery is present, the battery holds the voltage substantially constant. A level shifter shifts the voltage at the node. If no battery is present, the shifted voltage will fall below a predetermined threshold, but if a battery is present, the shifted voltage will remain above the predetermined threshold. A ground sense comparator detects whether or not the shifted voltage is below the predetermined threshold, and provides a battery detection signal accordingly. A controllable charge driver couples power from a power supply through to a battery, to charge the battery. An integrated circuit provides logic functions of the apparatus, including logic functioning as a charge controller. The charge controller is responsive to the battery detection signal to provide a charge drive signal to turn on the controllable charge driver only if a battery is present. The battery charger is capable of fast charging a wide variety of batteries according to a user-selectable charge rate.