High performance inverter charger system

• US 7,710,077 B2
• Filed: 10/06/2006
• Issued: 05/04/2010
• Est. Priority Date: 10/08/2005
• Status: Expired due to Fees

• Current Assignee: HDM Systems Corporation
• Original Assignee: HDM Systems Corporation
• Inventors: Liu, David S. C., Zeng, James Jin Xiong
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): PIGGUSH, AARON C
• Application Number:
  US11/544,104
• Publication Number:
  US 20070081372A1
• Time in Patent Office: 1,306 Days
• Field of Search: 320/163, 320/135, 320/136, 320/111, 363/132, 363/95, 363/109
• US Class Current: 320/136
• CPC Class Codes: H02M 7/5387 in a bridge configuration

Abstract

Techniques for high performance inverter charger systems are described herein. In one embodiment, a power supply system includes, but is not limited to, an inverter to generate an AC (alternating current) output based on a DC (direct current) input, a current sensing circuit coupled to the inverter to sense an amount of current drawn from the inverter, and a microcontroller coupled to the inverter and the current sensing circuit to reduce the AC output of the inverter according to a predetermined algorithm stored within the microcontroller, in response to a detection that the amount of current drops below a predetermined threshold. Other methods and apparatuses are also described.

Claims

1. A power supply system, comprising:

an inverter to generate an AC (alternating current) output based on a DC (direct current) input;

a current sensing circuit coupled to the inverter to sense an amount of current drawn from the inverter; and

a microcontroller coupled to the inverter and the current sensing circuit to shutdown the AC output of the inverter according to a predetermined algorithm stored within the microcontroller, in response to a detection that the amount of current drops below a predetermined threshold, wherein the predetermined algorithm and the predetermined threshold are programmed as part of programmable instructions stored in a machine-readable storage medium within the microcontroller, and wherein the programmable instructions, when executed by the microcontroller, cause the microcontroller to shutdown the AC output of the inverter according to the predetermined algorithm, in response to the detection that the amount of current drops below the predetermined threshold.

2. The system of claim 1, wherein the current sensing circuit comprises:

a current sense resister to sense the amount of current drawn from the inverter, generating a current sense voltage representing the current being sensed;

a comparator to compare the current sense voltage with the predetermined threshold, generating a signal representing whether the amount of current drops below the predetermined threshold, wherein the microcontroller operates based on the signal.

3. The system of claim 2, wherein the current sensing circuit further comprises an amplifier coupled to the current sense resister and the comparator to amplify the current sense voltage, and wherein the comparator compares the amplified current sense voltage with the predetermined threshold.

4. The system of claim 2, wherein the comparator comprises a first input to receive the current sense voltage from the current sense resister and a second input to receive a reference voltage, wherein the reference voltage is controlled by the microcontroller, and wherein an output of the comparator is used to determine a current limit of the inverter.

5. The system of claim 4, wherein the microcontroller is configured to set a first current limit during a first period of time and to set a second current limit during a second period of time after the first period of time, wherein the first and second current limits are different and are programmed as part of programmable instructions stored in the storage medium of the microcontroller.

6. The system of claim 5, wherein the first current limit is higher than the second current limit.

7. The system of claim 1, wherein the microcontroller is programmable including programming the predetermined algorithm.

8. The system of claim 7, wherein the predetermined algorithm comprises a period of time that has to lapse after the amount of current drawn drops below the predetermined threshold and before turning off the inverter.

9. The system of claim 1, further comprising a pulse width modulator (PWM) coupled to the microcontroller to adjust a duty cycle of the inverter in response to an output of the microcontroller.

10. The system of claim 9, further comprising:

a battery coupled to provide the DC input to the inverter; and

a fuel gauge coupled to the battery and the microcontroller to monitor operating conditions of the battery, wherein the microcontroller is configured to control operating the inverter based on the operating conditions of the battery provided by the fuel gauge.

11. The system of claim 10, wherein the operating conditions of the battery comprise at least one of an output voltage of the battery, an amount of current drawn from the battery, and a remaining power available from the battery.

12. The system of claim 11, wherein the microcontroller is a first microcontroller and the predetermined algorithm is a first predetermined algorithm, and wherein the fuel gauge further comprises a second microcontroller to generate a control signal to the first microcontroller based on the operating conditions of the battery using a second predetermined algorithm.

13. A power supply system, comprising:

an inverter to generate an AC (alternating current) output based on a DC (direct current) input; and

a microcontroller coupled to the inverter to adjust the AC output of the inverter according to a predetermined algorithm stored within the microcontroller, when the AC output of the inverter satisfies a predetermined condition for a predetermined period of time, wherein at least one of the predetermined algorithm, the predetermined condition, and the predetermined period of time are user programmable within the microcontroller, wherein the microcontroller is programmed to turn off the inverter when an amount of current drawn from the inverter drops below a predetermined threshold for the predetermined period of time,

wherein the predetermined algorithm, the predetermined threshold, and the predetermined period of time are programmed as part of programmable instructions stored in a machine-readable storage medium within the microcontroller, and wherein the programmable instructions, when executed by the microcontroller, cause the microcontroller to turn off the inverter when the amount of current drawn from the inverter drops below the predetermined threshold for the predetermined period of time.

14. The system of claim 13, further comprising:

an AC input to receive a shore power; and

a charger configured to charge a battery coupled to the DC input when the shore power is detected by the microcontroller coupled to the AC input,

wherein the microcontroller is programmed to switch the power supply system from an inverter mode to a charging mode by turning off the inverter and controlling the charger to charge the battery using the shore power received from the AC input, and wherein the microcontroller is further programmed to allow the shore power to be provided at the AC output when the inverter is turned off.