Patent Application
20140361615
1. Technical Field
The present disclosure relates to electronic devices, and particularly to an electronic device with a forced shutdown function.
2. Description of Related Art
Batteries of some portable electronic devices are built-in and not meant to be removed. When such an electronic device is connected to an external power source, the external power source not only provides power to the electronic device, but also charges the built-in batteries. Referring to
Many aspects of the present disclosure should be better understood with reference to the following drawings. The units in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding portions throughout the several views.
Embodiments of the present disclosure will now be described in detail, with reference to the accompanying drawings.
A first terminal of the resistor 27 is connected between the power source interface 21 and the voltage input pin of the voltage converter 25. A second terminal of the resistor 27 is connected between the mechanical button 29 and the RC parallel circuit 28. In this embodiment, the second terminal of the resistor 27 is connected to the RC parallel circuit via a diode D. The anode of the diode D is connected to the second terminal of the resistor 27, and the cathode of the diode D is connected to a first terminal of the RC parallel circuit 28. The first terminal of the RC parallel circuit 28 is further connected to the enable pin of the voltage converter 25. A second terminal of the RC parallel circuit 28 is grounded.
In this embodiment, the mechanical button 29 is moved between a first position and a second position. When the mechanical button 29 is in the first position, the second terminal of the resistor 27 is connected to a power source Vcc. When the mechanical button 29 is in the second position, the second terminal of the resistor 27 is grounded. Specifically, the mechanical button 29 includes an insulated main body 291, an operable portion 292 slidably received in the main body 291, a conductive contact portion 293 secured to an end of the operable portion 292, a first conductive terminal 294, a second conductive terminal 295, and a third conductive terminal 296. All of the terminals 294, 295, and 296 are spaced apart from each other and arranged on the main body 291. The first conductive terminal 294 is connected to the power source Vcc via a resistor R3. The second conductive terminal 295 is connected to the second terminal of the resistor 27. The third conductive terminal 296 is grounded. The distance between the first conductive terminal 294 and the second conductive terminal 295 is the same as the distance between the second conductive terminal 295 and the third conductive terminal 296. The conductive portion 293 can contact the first conductive terminal 294 and the second conductive terminal 295 at the same time, or contact the second conductive terminal 295 and the third conductive terminal 296 at the same time. When the operable portion 292 is slid to cause the mechanical button 29 to be in the first position, the conductive portion 293 contacts the first conductive terminal 294 and the second conductive terminal 295 at the same time. When the operable portion 292 is slid to cause the mechanical button 29 to be in the second position, the conductive portion 293 contacts the second conductive terminal 295 and the third conductive terminal 296 at the same time. In this embodiment, at least a portion of the conductive portion 293 is made of magnetic material. Thus, when the mechanical button 29 is released, the attraction among the conductive portion 293, the first conductive terminal 294, and the second conductive terminal 295, or the attraction among the conductive portion 293, the second conductive terminal 295, and the third conductive terminal 296 can cause the mechanical button 29 to remain in the first position or the second position.
In this embodiment, when the power source interface 21 is connected to an external power source, and the mechanical button 29 is slid to the first position, the external power source charges the built-in battery unit 24 and provides power to the voltage converter 25. The voltage at the enable pin En is logic high, thus the voltage converter 25 works. The external power source further charges a capacitor C of the RC parallel circuit 28. If the electronic device 200 crashes, the connection between the electronic device 200 and the external power source is cut off, and the mechanical button 29 is slid to the second position. At this point, as the resistor 27 is grounded, the built-in battery unit 23 cannot provide power to the RC parallel circuit 28, and the capacitor C discharges. While the capacitor C discharges, the voltage at the enable pin En is still logic high, thus the voltage converter 25 still works to convert the power provided by the built-in battery unit 23 to the work voltage of the electronic components 26. When the capacitor C fully discharges, the voltage at the enable pin En is changed to be logic low, the voltage converter 25 is disabled, thus the electronic components 26 are disabled, and the electronic device 200 is shut down.
With such configuration, when the electronic device 200 cannot be normally shut down, the mechanical button 29 can be used to force shut down of the electronic device 200.
Although the present disclosure has been specifically described on the basis of the exemplary embodiment thereof, the disclosure is not to be construed as being limited thereto. Various changes or modifications may be made to the embodiment without departing from the scope and spirit of the disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013102211290 | Jun 2013 | CN | national |
