Charging control circuit

• US 9,270,136 B2
• Filed: 03/27/2014
• Issued: 02/23/2016
• Est. Priority Date: 01/24/2014
• Status: Expired due to Fees

• Current Assignee: Primax Electronics Limited
• Original Assignee: Primax Electronics Limited
• Inventors: Hsueh, Tsung-Wen, Chen, Yi-Guang, Shih, Yu Yen
• Primary Examiner(s): Memula, Suresh
• Application Number:
  US14/227,219
• Publication Number:
  US 20150214772A1
• Time in Patent Office: 698 Days
• Field of Search: 320/107
• US Class Current: 1/1
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters

Abstract

A charging control circuit includes a charging module, a switch element, a load detecting element, and an adjusting element. According to the power consumption of a chargeable battery of an electronic device, the load detecting element issues a load range signal. According to the load range signal, the adjusting element issues a control voltage to the switch element. According to the control voltage, the switch element is turned on, and the magnitude of a control current from the switch element is correspondingly adjusted. By the charging module, a charging current corresponding to the control current is provided to charge the chargeable battery. Consequently, the magnitude of the charging current is controlled according to the operating situation of the electronic device, and the charging speed is changed.

Claims

1. A charging control circuit installed in an electronic device and connected with a chargeable battery of the electronic device for charging the chargeable battery, the charging control circuit comprising:

a charging module connected with the chargeable battery, and providing a charging current to the chargeable battery so as to charge the chargeable battery;

a switch element connected with the charging module, wherein when the switch element is turned on, a control current is outputted from the switch element to the charging module;

a load detecting element connected with the chargeable battery, wherein the load detecting element issues a load range signal according to a voltage drop of the chargeable battery; and

an adjusting element connected with the switch element and the load detecting element, wherein the adjusting element issues a control voltage to the switch element according to the load range signal, so that a magnitude of the control current from the switch element is correspondingly adjusted, wherein as the voltage drop increases, the charging current increases.

2. The charging control circuit according to claim 1, wherein plural voltage ranges are previously stored in the load detecting element, wherein after the voltage drop is received by the load detecting element, the load detecting element judges that the voltage drop lies in a target voltage range of the plural voltage ranges, and generates the load range signal corresponding to the target voltage range.

3. The charging control circuit according to claim 2, wherein the load detecting element comprises plural pins, wherein the plural pins are connected with the adjusting element, and plural logic level signals are respectively outputted from the plural pins according to the target voltage range, wherein the plural logic level signals outputted from the plural pins are collaboratively defined as the load range signal.

4. The charging control circuit according to claim 1, wherein when the control voltage is transmitted from the adjusting element to the switch element, an open width of a channel of the switch element is adjusted by the adjusting element according to the control voltage, so that a channel current of the channel flows through the channel and the control current is outputted to the charging module, wherein as the control voltage increases, the open width of the channel increases, the channel current flowing through the channel increases, and the control current increases.

5. The charging control circuit according to claim 1, wherein the charging module comprises:

a fixed resistor connected with the adjusting element in series, wherein the control current flows through the fixed resistor; and

a charging control element connected with the chargeable battery and the fixed resistor, wherein according to the control current, the charging control element generates the charging current and issues the charging current to the chargeable battery.

6. The charging control circuit according to claim 5, wherein a gate terminal of the switch element is connected with the adjusting element, a drain terminal of the switch element is connected with the fixed resistor, and a source terminal of the switch element is connected to ground, wherein the switch element is an N-type metal-oxide-semiconductor field-effect transistor.

7. The charging control circuit according to claim 5, wherein a gate terminal of the switch element is connected with the adjusting element, a drain terminal of the switch element is connected with the fixed resistor, and a source terminal of the switch element is connected to ground, wherein the switch element is a P-type metal-oxide-semiconductor field-effect transistor.

8. The charging control circuit according to claim 1, wherein the load detecting element is an analog-to-digital converter, and the adjusting element is a digital-to-analog converter, wherein the load detecting element and the adjusting element are integrated into a microprocessor.

9. The charging control circuit according to claim 1, wherein the load detecting element is an analog-to-digital converter, and the adjusting element is a digital-to-analog converter, wherein the load detecting element is included in a microprocessor, and the adjusting element is disposed outside the microprocessor and connected with the microprocessor.