Battery charge circuit with multi-charge stage and method thereof

• US 7,375,491 B2
• Filed: 12/16/2005
• Issued: 05/20/2008
• Est. Priority Date: 12/16/2005
• Status: Expired due to Fees

• Current Assignee: Sunjett Corporation
• Original Assignee: Sunjett Corporation
• Inventors: Lin, Sheng-Chan
• Primary Examiner(s): Nguyen; Matthew V.
• Assistant Examiner(s): Zhang; Jue
• Application Number:
  US11/304,730
• Publication Number:
  US 20070139011A1
• Time in Patent Office: 886 Days
• Field of Search: 320141-146, 320107-115
• US Class Current: 320/107
• CPC Class Codes: H02J 7/0071 with a programmable schedule

Abstract

A charge circuit having multi charge stages for charging at least one battery includes: a first current generating circuit for generating a first charge power having a first charge current in pulse form with a first frequency and a first charge voltage to charge the at least one battery; a voltage generating circuit connected to the first current generating circuit for controlling the first charge power having a first charge current in pulse form with a first frequency and a first charge voltage; a voltage control circuit connected to the voltage generating circuit for generating a first constant voltage and/or a second constant voltage; and a second current generating circuit connected to the voltage generating circuit for generating a variant power comprising a variant current in pulse form with a second frequency wherein a charge voltage included in the variant power varies with the second frequency.

Claims

1. A charge circuit for charging at least one battery comprising:

a first current generating circuit for generating a first charge power having a first charge current in pulse form with a first frequency and a first charge voltage to charge the at least one battery, wherein the first charge current in the first charge stage remains substantially constant, and the first charge voltage remains a first constant voltage;

a voltage generating circuit connected to the first current generating circuit for controlling the first charge power;

a voltage control circuit connected to the voltage generating circuit for generating a first constant voltage or a second constant voltage; and

a second current generating circuit connected to the voltage generating circuit for generating a variant power comprising a variant current in pulse form with a second frequency, wherein a charge voltage included in the variant power varies with the second frequency,

wherein the voltage control circuit comprises;

a second transistor and a third transistor;

an eleventh resistor and a twelfth resistor connected in series;

a thirteenth resistor having a terminal that is connected to the second transistor;

a fourteenth resistor connected to the third transistor;

a fifteenth resistor is connected to the second transistor; and

a sixteenth resistor is connected to the second transistor;

wherein when the third transistor turns on, the first constant voltage is generated, and when the third transistor turns off, the second constant voltage is generated.

2. The circuit of claim 1, wherein the first current generating circuit comprises:

a first opto-coupler and a first resistor connected to the first opto-coupler.

3. The circuit of claim 2, wherein the first current generating circuit further comprises a microprocessor and a control circuit to supply a small power source to the microprocessor to prevent shut down of the microprocessor, and the control circuit comprises a third resistor, a fourth resistor connected to the third resistor, and a first transistor having a base connected to the third resistor, and an emitter connected to a terminal of the first opto-coupler.

4. The circuit of claim 3, wherein the first current generating circuit further comprises a pulse provider connected to the control circuit, the pulse provider comprising two diodes connected in series.

5. The circuit of claim 1, wherein the voltage generating circuit comprises:

a second opto-coupler;

a fifth resistor connected to the second opto-coupler;

a series circuit for feedback compensation, the series circuit including a sixths resistor, a sevenths resistor, a first capacitor, and a second capacitor, wherein the sixth resistor has a terminal that is connected to a terminal of the fifth resistor;

eighth and ninth resistors connected in series; and

a first Zener diode connected with the ninth resistor in parallel for feedback voltage control.

6. The circuit of claim 5, wherein the voltage generating circuit further comprises a tenth resistor connected in parallel with the ninth resistor.

7. The circuit of claim 1, wherein the second current generating circuit comprises:

a second Zener diode connected to the sixteenth resistor;

a third diode connected to the second Zener diode;

a seventeenth resistor connected with the third diode in series; and

eighteenth and nineteenth resistors that are connected in series, wherein the seventeenth resistor has a terminal that is connected between the eighteenth resistor and the nineteenth resistor.

8. A charge system for charging at least one battery, comprising:

a panel provided with a plurality of control buttons, each of which corresponds to a respective one of a plurality of specific functions;

a microprocessor executing the specific functions when the corresponding control buttons are pressed; and

a charge circuit controlled by the microprocessor for charging the at least one battery, the charge circuit comprising;

a first current generating circuit for generating a first charge power having a first charge current in pulse form with a first frequency and a first charge voltage to charge the at least one battery, wherein the first charge current in the first charge stage remains substantially constant, the first charge voltage remains a first constant voltage;

a voltage generating circuit connected to the first current generating circuit for controlling the first charge power;

a voltage control circuit connected to the voltage generating circuit for generating a first constant voltage or a second constant voltage; and

a second current generating circuit connected to the voltage generating circuit for generating a variant power comprising a variant current in pulse form with a second frequency, wherein a charge voltage included in the variant power varies with the second frequency,

wherein the voltage control circuit comprises;

a second transistor and a third transistor;

an eleventh resistor and a twelfth resistor connected in series;

a thirteenth resistor having a terminal that is connected to the second transistor;

a fourteenth resistor connected to the third transistor;

a fifteenth resistor is connected to the second transistor; and

a sixteenth resistor is connected to the second transistor;

wherein when the third transistor turns on, the first constant voltage is generated, and when the third transistor turns off, the second constant voltage is generated.

9. The system of claim 8, further comprising a plug for receiving electrical power source.

10. The system of claim 8, further comprising a display provided on the panel.

11. The system of claim 8, wherein the microprocessor issues an error message when the charge system does not connect with a battery.

12. The system of claim 8, wherein the microprocessor issues an error message when the charge system detects at least one short cell in the battery.

13. The system of claim 8, wherein the microprocessor issues an error message when the charge system detects at least open short cell in the battery.

14. The system of claim 13, wherein when the battery voltage is smaller than a first predetermined voltage and the battery voltage is greater than a second predetermined voltage, the error message of open cell is generated.

15. The system of claim 8, wherein the microprocessor issues an error message when the charge system charges the battery over a predetermined time.

16. The system of claim 8, wherein the first current generating circuit comprises:

a first photodiode; and

a first resistor connected to the first photodiode.

17. The system of claim 16 wherein the first current generating circuit further comprises a control circuit to supply a small power source to the microprocessor to prevent shut down of the microprocessor, the control circuit comprises a third and a fourth resistor connected in series;

and a first transistor having a base connected to the fourth resistor, a emitter connected to the third terminal of the first photodiode.

18. The system of claim 17, wherein the first current generating circuit further comprises a control circuit to supply a small power source to the microprocessor to prevent shut down of the microprocessor, the control circuit comprises a third and a fourth resistor connected in series;

and a first transistor having a base connected to the fourth resistor, a emitter connected to the third terminal of the first photodiode.

19. The system of claim 17, wherein the first current generating circuit further comprises a pulse provider with minimum duty to the control circuit, the pulse provider comprising two diodes connected in series.

20. The system of claim 8, wherein the voltage generating circuit comprises:

a second opto-coupler;

a fifth resistor connected to the second opto-coupler;

a series circuit for feedback compensation, the series circuit including a sixth resistor, a seventh resistor, a first capacitor, and a second capacitor, wherein the sixth resistor has a terminal that is connected to a terminal of the fifth resistor;

eighth and ninth resistors connected in series; and

a first Zener diode connected with the ninth resistor in parallel for feedback voltage control.

21. The system of claim 20, wherein the voltage generating circuit further comprises a tenth resistor connected in parallel with the ninth resistor.

22. The system of claim 8, wherein the second current generating circuit comprises:

a second Zener diode connected to the sixteenth resistor;

a third diode connected to the second Zener diode;

a seventeenth resistor connected with the third diode in series; and

eighteenth and nineteenth resistors that are connected in series, wherein the seventeenth resistor has a terminal that is connected between the eighteenth resistor and the nineteenth resistor.