Charging apparatus and charging method

• US 20040008007A1
• Filed: 05/01/2003
• Published: 01/15/2004
• Est. Priority Date: 05/15/2002
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Yamazaki, Kazuo, Nagai, Tamiji, Yamamoto, Tadahisa
• Granted Patent: US 7,023,179 B2
• Time in Patent Office: Days
• US Class Current: 320/134
• CPC Class Codes: H02J 2207/40 adapted for charging from various sources, e.g. AC, DC or multivoltage
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current
• CPC Class Codes: H02J 7/007182 in response to battery voltage

Abstract

In the case of charging by a charging apparatus having a plurality of input terminals to which external power sources for charging a secondary battery are inputted, it is prevented that a current of the inputted power source is outputted to the outside from the other input terminals for charging which are not used. If there are inputs from a plurality of input terminals, the input power sources are controlled so that the battery is optimally charged. pnp-type transistors Q1 and Q2 are arranged between two input terminals of a terminal 11 for an external power adaptor and a terminal 12 for a holder and a secondary battery E1, respectively. When a control IC 13 detects an input power voltage of one of the transistors, the transistor on the detected side is turned on. If the control IC 13 detects both input power voltages, a priority is allocated under predetermined conditions and the secondary battery E1 is charged by the power source of the higher priority.

Claims

1. A charging apparatus comprising:

first and second input terminals to which power voltage sources are connected;

first and second semiconductor devices for power control in which said first and second input terminals are connected to input electrodes, respectively;

a secondary battery to which output electrodes of said first and second semiconductor devices for power control are connected in common and which is connected between said common connection electric potential point and a reference electric potential point;

a control circuit for controlling a terminal voltage and a charge current of said secondary battery to desired values; and

switching signal generating means for detecting voltages which are generated at the input electrodes of said first and second semiconductor devices for power control and generating a switching signal for turning on a circuit between the input and output electrodes of said semiconductor device for power control at which the voltage has been detected.

2. An apparatus according to claim 1, wherein if the voltages are detected from the input electrodes of both of said first and second semiconductor devices for power control, the input power sources which are inputted from said first and second input terminals are controlled by turning on the circuit between the input and output electrodes of one of said first and second semiconductor devices for power control in accordance with a preset priority.

3. An apparatus according to claim 1, wherein if the voltages are detected from the input electrodes of both of said first and second semiconductor devices for power control, the input power sources which are inputted from said first and second input terminals are controlled by turning on the circuit between the input and output electrodes of one of said first and second semiconductor devices for power control in accordance with a priority such that the semiconductor device for power control on the side where the voltage of a predetermined voltage value or more has been detected first is preferentially used.

4. An apparatus according to claim 1, wherein if the voltages are detected from the input electrodes of both of said first and second semiconductor devices for power control, the input power sources which are inputted from said first and second input terminals are controlled by turning on the circuit between the input and output electrodes of one of said first and second semiconductor devices for power control in accordance with a priority such that the semiconductor device for power control on the side where the voltage is equal to or larger than a predetermined voltage value and is lower is preferentially used.

5. An apparatus according to claim 1, wherein if the voltages are detected from the input electrodes of both of said first and second semiconductor devices for power control, the input power sources which are inputted from said first and second input terminals are controlled by turning on the circuit between the input and output electrodes of one of said first and second semiconductor devices for power control in accordance with a priority such that the semiconductor device for power control on the side where an electric power is lower is preferentially used.

6. An apparatus according to claim 1, wherein if the power voltages are detected from both of said first and second input terminals, the input power sources which are inputted from said first and second input terminals are controlled by turning on the circuit between the input and output electrodes of one of said semiconductor devices for power control in accordance with a priority such that the semiconductor device for power control on the side where the power voltage is closest to an input reference voltage is preferentially used.

7. An apparatus according to claim 1, wherein the power voltages are inputted from both of said first and second input terminals, if the current flowing in said secondary battery is equal to or less than a reference value, the circuit between the input and output electrodes of each of said first and second semiconductor devices for power control is turned on, and if the current flowing in said secondary battery is larger than said reference value, the circuit between the input and output electrodes of one of said first and second semiconductor devices for power control is turned on, thereby controlling the input power sources which are inputted from said first and second input terminals.

8. An apparatus according to claim 1, wherein said first and second input terminals are a terminal for connecting an AC adaptor and a terminal for a holder.

9. A charging method for a charging apparatus comprising:

first and second input terminals to which power voltage sources are connected;

first and second semiconductor devices for power control in which said first and second input terminals are connected to input electrodes, respectively;

a secondary battery to which output electrodes of said first and second semiconductor devices for power control are connected in common and which is connected between said common connection electric potential point and a reference electric potential point; and

a control circuit for controlling a terminal voltage and a charge current of said secondary battery to desired values,

wherein said method has

a detecting step of detecting voltages which are generated at the input electrodes of said first and second semiconductor devices for power control, and

a step of turning on a circuit between the input and output electrodes of said semiconductor device for power control at which the voltage has been detected by said detecting step.