PORTABLE DEVICE WITH AN AUTOMATIC POWER OFF PROTECTION AND METHOD FOR SAME

• US 20070250732A1
• Filed: 04/18/2007
• Published: 10/25/2007
• Est. Priority Date: 04/19/2006
• Status: Active Grant

• Current Assignee: Hong Fu Jin Precision Industry (Shenzhen) Co., Ltd. (Hon Hai Precision Industry Co., Ltd.), Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hon Hai Precision Industry Co., Ltd.
• Inventors: Chuang, Tsung-Jen, Liu, Jian-Lin, Wong, Shih-Fang
• Granted Patent: US 7,827,420 B2
• Time in Patent Office: Days
• US Class Current: 713/324
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode

Abstract

A portable device with an automatic power off protection and a method of achieving such a protection are related. The portable device circuit comprises a switch unit, a main body, and a battery. The main body includes an acceleration transducer that samples an analog acceleration signal; an analog-to-digital converter (ADC) that converts the sampled analog acceleration signal into a digital acceleration value; a memory that stores a critical acceleration value and an interrupt flag; and a micro-control unit (MCU) that compares the digital acceleration values with the critical acceleration value and the comparing result which may or may not change the value of the interrupt flag. When the acceleration of the portable device is greater than the critical acceleration and the interrupt flag is enable, the MCU sends a break signal to the switch unit to power off the portable device.

Claims

1. A portable device with an automatic power off protection circuit, comprising a switch unit, a main body, and a battery;

the battery powers the main body via the switch unit;

wherein;

the main body comprises;

an acceleration transducer for sampling an analog acceleration signal;

an analog-to-digital converter (ADC) for converting the analog acceleration signal into a digital acceleration value;

a memory for storing a critical acceleration value and an interrupt flag; and

a micro-control unit (MCU) for comparing the digital acceleration value with the critical acceleration value and the comparing result that may or may not change the value of the interrupt flag;

wherein the MCU further determines whether to power off the portable device according to the comparing result and the value of the interrupt flag.

2. The portable device according to claim 1, wherein a value of the interrupt flag is either of an enable value or a disable value.

3. The portable device according to claim 2, wherein an initial value of the state of the interrupt flag is set to the disable value when the portable device is powered on.

4. The portable device according to claim 3, wherein if the digital acceleration value is greater than the critical acceleration value, and the value of the interrupt flag is disabled, the MCU changes the value of the interrupt flag to the enable value.

5. The portable device according to claim 3, wherein if the digital acceleration value is less than the critical acceleration value, and the value of the interrupt flag is disabled, the MCU does not change the value of the interrupt flag.

6. The portable device according to claim 3, wherein if the digital acceleration value is less than the critical acceleration value and the value of the interrupt flag is enabled, the MCU changes the value of the interrupt flag to the disable value.

7. The portable device according to claim 3, wherein if the digital acceleration value is greater than the critical acceleration value and the value of the interrupt flag is enabled, the MCU sets the value of the interrupt flag to the disable value, and at the same time the MCU generates a break signal and sends the break signal to the switch unit to power off the portable device.

8. An automatically power off method for a portable device, wherein the portable device has a memory for storing the critical acceleration value and an interrupt flag for recording an acceleration state of the portable device, the method comprising the steps of:

sampling an analog acceleration signal of the portable device;

converting the analog acceleration signal into a digital acceleration value;

comparing the digital acceleration value with the critical acceleration value and producing a comparing result; and

powering off the portable device according to the comparing result and the interrupt flag.

9. The automatically power off method according to claim 8, wherein the comparing step comprises:

changing or not changing a value of the interrupt flag according to the comparing result.

10. The automatically power off method according to claim 9, wherein the comparing step further comprises:

enabling the interrupt flag if the digital acceleration value is greater than the critical acceleration value and the interrupt flag is disabled.

11. The automatically power off method according to claim 9, wherein the comparing step further comprises:

not changing the interrupt flag if the digital acceleration value is less than the critical acceleration value and the interrupt flag is disabled.

12. The automatically power off method according to claim 9, wherein the comparing step further comprises:

disabling the interrupt flag if the digital acceleration value is less than the digital acceleration value and the interrupt flag is enabled.

13. The automatically power off method according to claim 9, wherein the comparing step further comprises:

disabling the value of the interrupt flag if the digital acceleration value is greater than the critical acceleration value and the interrupt flag is enabled, and sending a break signal to power off the portable device.