Charge control system using pulse width modulation
View Patent ↗A charge control system for lithium battery using pulse width modulation is provided, and it detects the existing voltage of the charging lithium battery by a voltage detector and passes this voltage value to a microprocessor preset in the hand-held apparatus. Thus, the microprocessor can decide the applicable charge stage and confirm the status of the charging battery depending on the different Voltage values in real time. Next, the microprocessor controls a control unit by a pulse width modulation signal to modulate the power-source, which comes from an adaptor, as a constant current or a constant voltage to charge the battery. Accordingly, the charge process is completed by repeating the voltage detection and the duty cycle modulation of the control unit.
1. A charge control system for a lithium battery using pulse width modulation, applied to a hand-held apparatus, comprising:
a microprocessor processing and controlling said hand-held apparatus;
a control unit electrically connected to said microprocessor and receiving a control signal which comes from said microprocessor;
a charging unit electrically connected to said control unit; and a voltage detector including an input terminal to receive an analog voltage value and an output terminal to electrically connect to said microprocessor.
2. The charge control system for the lithium battery using pulse width modulation according to claim 1 , wherein said control unit is a switch.
3. The charge control system for the lithium battery using pulse width modulation according to claim 1 , wherein said charging unit includes a power input port which is a universal serial bus.
4. The charge control system for the lithium battery using pulse width modulation according to claim 1 , wherein said voltage detector further includes an analog-to-digital converter to convert said analog voltage value to a digital voltage value, and said voltage detector sends said digital voltage value to said microprocessor.
5. The charge control system for the lithium battery using pulse width modulation according to claim 1 , wherein said control signal is a pulse width modulation signal to control a duty cycle of said control unit.
6. The charge control system for the lithium battery using pulse width modulation according to claim 5 , wherein said pulse width modulation signal is produced by a firmware set in said microprocessor.
7. The charge control system for the lithium battery using pulse width modulation according to claim 1 , wherein said microprocessor further includes a timer.
8. The charge control system for the lithium battery using pulse width modulation according to claim 1 , wherein said control unit is a switch-control circuit.
9. The charge control system for the lithium battery using pulse width modulation according to claim 8 , wherein said switch-control circuit is at least one transistor.
10. The charge control system for the lithium battery using pulse width modulation according to claim 1 , wherein said charging unit includes a power input port which is a plug.
11. The charge control system for the lithium battery using pulse width modulation according to claim 1 , wherein said charging unit electrically connects a lithium battery and charges said lithium battery.
12. The charge control system for the lithium battery using pulse width modulation according to claim 1 , wherein said microprocessor and said voltage detector are integrated into an integrated circuit.
13. Hand-held apparatus, comprising:
a shell;
a central control module including at least a microprocessor set in said shell;
an application module set in said shell and electrically connected to said central control module;
a power module set in said shell to provide power;
a display module set in said shell and electrically connected to said central control module; and
a charging control module set in said shell and electrically connected to said central control module, wherein said charging control module includes:
a voltage detecting unit, one terminal of said voltage detecting unit electrically connected to said power module and the other terminal of said voltage detecting unit electrically connected to said microprocessor; and
a control unit, one terminal of said control unit electrically connected to said microprocessor to receive a pulse width modulation signal from said microprocessor.
14. The hand-held apparatus according to claim 13 , wherein another terminal of said control unit of said charging control module is electrically connected to a charger and the duty cycle of said charger is controlled by said pulse width modulation signal.
15. The hand-held apparatus according to claim 14 , wherein another terminal of said charger is electrically connected to said power module to get the power source of said hand-held apparatus.
16. The hand-held apparatus according to claim 13 , wherein said voltage detecting unit includes an analog-to-digital converter to convert an analog voltage value of said power module to a digital voltage value, and said voltage detecting unit sends said digital voltage value to said microprocessor.
17. The hand-held apparatus according to claim 13 , wherein said microprocessor further includes a timer.