The present disclosure relates to over-current regulating systems.
Electronic devices, such as notebook computers, include a power supply unit, such as a Voltage Regulator Module (VRM). The power supply unit supplies power to a load such as a central processing unit. When an operating frequency of the load increases, a required current of the load may be greater than an over-current tolerance of the power supply unit, which may damage the power supply unit.
Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean “at least one.”
The filtering circuit 50 can include a fifth resistor R5 and a capacitor C1. A first end of the fifth resistor R5 can be electrically coupled to the output end of the first comparator 21, and a second end of the fifth resistor R5 can be electrically coupled to a first end of the capacitor C1. A second end of the capacitor C1 can be grounded.
The comparing circuit 30 can include a second comparator 31 and a controlling module 33. A negative electrode of the second comparator 31 can be electrically coupled to the fifth resistor R5 and the capacitor C1. The controlling module 33 can include a MOSFET, a sixth resistor R6, a seventh resistor R7, and an eighth resistor R8.
A grid of the MOSFET can be electrically coupled to a determining module 36. A drain of the MOSFET can be electrically coupled to a positive electrode of the second comparator 31, and a source of the MOSFET can be grounded via the sixth resistor R6. The determining module 36 can be electrically coupled to the power supply unit 10 and can determine if a voltage of the power supply unit 10 is greater than a limiting voltage. When the voltage of the power supply unit 10 is greater than the limiting voltage, the determining module 36 can send a high-level signal to switch on the MOSFET. When the voltage of the power supply unit 10 is less than the limiting voltage, the determining module 36 can send a low-level signal to switch off the MOSFET. A first end of the seventh resistor R7 can be electrically coupled to the positive electrode of the second comparator 31, and a second end of the seventh resistor R7 can be grounded. A first end of the eighth resistor R8 can be electrically coupled to the positive electrode of the second comparator 31, and a second end of the eighth resistor R8 can be electrically coupled to the battery 35.
When the power supply unit 10 is in use, the amplifying circuit 20 can amplify a voltage of the protecting resistor 15. The filtering circuit 20 can filter the voltage of the protecting resistor R0. The comparing circuit 30 can determine if the voltage of the protecting resistor R0 is greater than a first predetermined value when the MOSFET is switched on. When the voltage of the protecting resistor R0 is greater than the first predetermined value, the comparing circuit 30 can output a first controlling signal to the load 40 to reduce a work frequency of the load 40. In one embodiment, the controlling signal can be a low-level signal.
When the MOSFET is switched off, the battery 35 can supply power to the load 40. The comparing circuit 30 can determine if the voltage of the protecting resistor R0 is greater than a second predetermined value. When the voltage of the protecting resistor R0 is greater than the second predetermine value, the comparing circuit 30 can output a second controlling signal to the load 40 to reduce an operating frequency of the load 40.
Even though numerous characteristics and advantages of the present disclosure have been set forth in the foregoing description, together with details of the structure and function of the disclosure, the disclosure is illustrative only, and changes may be made in detail, especially in the matters of shape, size, and the arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
Number | Date | Country | Kind |
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102120992 | Jun 2013 | TW | national |