Patent Application
20160344325
The subject matter herein generally relates to a control circuit and an electronic system.
Fans are widely used in electronic systems, such as server systems, for heat dissipation. When enabled, the fans generally run at one speed which is the maximum speed.
Implementations of the present technology will now be described, by way of example only, with reference to the attached figures.
It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features. The description is not to be considered as limiting the scope of the embodiments described herein.
Several definitions that apply throughout this disclosure will now be presented.
The term “coupled” is defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The connection can be such that the objects are permanently connected or releasably connected. The term “comprising” means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in a so-described combination, group, series and the like.
The present disclosure is described in relation to an electronic system capable of outputting pulsed voltages of different amplitudes.
The control circuit 100 comprises a temperature sensor 10, a control chip 20, an amplitude adjustment unit 30, an inverting unit 40, and a connector 50. The control chip 20 is electrically coupled between the temperature sensor 10 and the connector 50. The control chip 20 is further electrically coupled to the connector 50 through the amplitude adjustment unit 30 and the inverting unit 40 in sequence. The connector 50 is electrically coupled to the fan 200. In use, the control chip 20 outputs a first pulse width modulation (PWM) signal P1 to the amplitude adjustment unit 30. The amplitude adjustment unit 30 adjusts amplitude of the first PWM signal P1 to output a second PWM signal P2 to the inverting unit 40. The inverting unit 40 reverses the second PWM signal P2 to output a third PWM signal P3 to the fan 200 through the connector 50, for controlling rotational speed of the fan 200. The control chip 20 further obtains instant temperature in the electronic system 1000 from the temperature sensor 10 and instant rotational speed of the fan 200 through the connector 50, to enable adjustment of the duty ratio of the first PWM signal P1 to the fan 200. In at least one embodiment, the control chip 20 is a complex programmable logic device (CPLD) core.
The control chip 20 comprises a serial clock pin SCL, a serial data pin SDA, an output pin I/O1, and an input pin I/O2. The serial clock pin SCL of the temperature sensor 10 is electrically coupled to the serial clock pin SCL of the control chip 20, and the serial data pin SDA of the temperature sensor 10 is electrically coupled to the serial data pin SDA of the control chip 20. The control chip 20 can thus obtain an instant temperature in the electronic system from the temperature sensor 10.
The amplitude adjustment unit 30 comprises two electronic switches Q1 and Q2 each comprising a first terminal, a second terminal, and a third terminal. The first terminal of the electronic switch Q1 is electrically coupled to the output pin I/O1 of the control chip 20 to obtain the first PWM signal P1 from the control chip 20, and is further grounded through a resistor R9. The second terminal of the electronic switch Q1 is grounded. The third terminal of the electronic switch Q1 is electrically coupled to a voltage source P3V3_AUX through a resistor R1. The first terminal of the electronic switch Q2 is electrically coupled to the third terminal of the electronic switch Q1. The second terminal of the electronic switch Q2 is grounded. The third terminal of the electronic switch Q2 is electrically coupled to a voltage source P12V, through resistor R2 and resistor R3 in sequence. The inverting unit 40 is electrically coupled to a node between the resistor R2 and the resistor R3 which is an output terminal O1 of the amplitude adjustment unit 30, to obtain the second PWM signal P2 from the output terminal O1 of the amplitude adjustment unit 30. In at least one embodiment, the electronic switch Q1 and the electronic switch Q2 are n-channel metal-oxide semiconductor field-effect transistors (NMOSFETs). The voltage of the voltage source P12V is 12V.
The inverting unit 40 comprises four electronic switches Q3-Q6 each comprising a first terminal, a second terminal, and a third terminal. The first terminals of the four electronic switches Q3-Q6 are electrically coupled to the output terminal O1 of the amplitude adjustment unit 30 and are further grounded through a capacitor C1. The second terminals of the four electronic switches Q3-Q6 are electrically coupled to the voltage source P12V. The third terminals of the four electronic switches Q3-Q6, as an output terminal O2 of the inverting unit 40, are electrically coupled to the connector 50, to output the third PWM signal P3 to the connector 50. In at least one embodiment, the four electronic switches Q3-Q6 are p-channel metal-oxide semiconductor field-effect transistors (PMOSFETs).
The connector 50 comprises a grounding pin 1, a power supply pin 2, a detecting pin 3, and a control pin 4. The grounding pin 1 is grounded. The power supply pin 2 is electrically coupled to the output terminal O2 of the inverting unit 40 and is further grounded through a capacitor C2. The detecting pin 3 is electrically coupled to a positive pole of a diode D1. The detecting pin 3 is further electrically coupled to the output terminal O2 of the inverting unit 40 through a resistor R7. The detecting pin 3 is also electrically coupled to the input pin I/O2 of the control chip 20 through two resistors R5 and R6, for the control chip 20 to obtain the instant rotational speed of the fan 200 through the connector 50. A negative pole of the diode D1 is electrically coupled to the output terminal O2 of the inverting unit 40. A node between the two resistors R5 and R6 is grounded through a capacitor C3 and is further grounded through a resistor R8. The control pin 4 is electrically coupled to the output terminal O2 of the inverting unit 40 through a resistor R4.
Referring to
Referring to
The embodiments shown and described above are only examples. Many details are often found in the art such as the other features of a control circuit and an electronic system. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the details, especially in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the embodiments described above may be modified within the scope of the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201510251832.5 | May 2015 | CN | national |
