Patent ID: 6300743
Filing Date: 2001-10-09
Classification: H02J

Abstract:
A method of communicating battery charging status from a phone to a charger, the method comprising the steps of:A. providing a power supply which can be coupled to a charger for supplying voltage and current;B. providing a charger havingi. a microprocessor;ii. at least one pocket for receiving a phone with a battery attached;iii. a first set of contacts for supplying a voltage and current;iv. a single wire interface coupled to the microprocessor;v. a charger contact coupled to the single wire interface;vi. a pull-up resistor coupled between the single wire interface and a positive voltage;vii. an identification display means capable of being driven into different states by the microprocessor;C. providing a phone havingi. charging circuitry disposed therein;ii. a battery;iii. electrical contacts coupled to the charging circuitry for receiving voltage and current; andiv. a phone contact for the single wire interface coupled to the charging circuitry;D. wherein the charging circuitry communicates battery charging status to the microprocessor by varying the duty cycle of a pulse with a predetermined period across the single wire interface.