CN100405735C - CPU fan circuit with over-voltage protection - Google Patents
CPU fan circuit with over-voltage protection Download PDFInfo
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- CN100405735C CN100405735C CNB2004100520680A CN200410052068A CN100405735C CN 100405735 C CN100405735 C CN 100405735C CN B2004100520680 A CNB2004100520680 A CN B2004100520680A CN 200410052068 A CN200410052068 A CN 200410052068A CN 100405735 C CN100405735 C CN 100405735C
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- drive part
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- fan circuit
- monitor portion
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Abstract
The present invention relates to a CPU fan circuit with overvoltage protection, which comprises a monitoring part, a driving part and a transistor, wherein the monitoring part comprises a rotate-speed counting signal input end and an output end for pulse-width modulating signals; the driving part comprises a rotate-speed counting signal input end and a second input end; the driving part is connected with a first power supply terminal; a first input terminal is connected with a second power supply terminal; a drain electrode of the transistor is connected with the second input end of the driving part, a source electrode of the transistor is connected with the earth, and a grid electrode of the transistor is connected with the output end for pulse-width modulating signals of the monitoring part. The output end for pulse-width modulating signals is connected with the first power supply terminal through an up pulling resistor. The CPU fan circuit with overvoltage protection also comprises a voltage stabilization part which is connected with the rotate-speed counting signal input end of the monitoring part for limiting the rotate-speed counting signal voltage which is input by the rotate-speed counting signal input end.
Description
[technical field]
The present invention relates to a kind of central processing unit (Central Processing Unit is hereinafter to be referred as CPU) fan circuit, particularly a kind of central processing unit fan circuit with overvoltage protection.
[background technology]
Existing C PU fan circuit as shown in Figure 1, it comprises a drive part 10 and a monitor portion 20.Drive part 10 is an integrated circuit, and it has three I/ O terminals 1,2,3, and lead-out terminal 3 output one TACH (tachometer) signals of drive part 10 are to the TACH input of monitor portion 20.Node between the TACH input of lead-out terminal 3 and monitor portion 20 is connected to the 5V power supply terminal by a resistance.Input terminal 2 is connected to the 12V power supply terminal, is connected to the end of filter capacitor C2 simultaneously, the other end ground connection of filter capacitor C2.Input terminal 1 is connected to the drain electrode of transistor Q7, the direct ground connection of the source electrode of transistor Q7, the grid of transistor Q7 is connected to PWM (pulse-width signal) output of monitor portion 20 by a resistance R 2, and the node between resistance R 2 and the monitor portion 20 is connected to the 5V power supply terminal by a pull-up resistor R3.
Fig. 2 has provided the internal circuit diagram of existing C PU fan circuit drive part 10, it comprises a transistor Q1, the collector electrode of transistor Q1 is drawn the lead-out terminal 3 output TACH signals of drive part 10, emitter is drawn the input terminal 1 of drive part 10, the base stage of transistor Q1 connects a pulse generator 12, two outputs of pulse generator 12 connect transistor Qa respectively, the base stage of Qb, two transistor Qa, the collector electrode of Qb respectively with two coil L1 of fan, L2 connects, this two coil L1, the end in addition of L2 is connected to the negative electrode of a diode D1, and the anode of this diode D1 is drawn the input terminal 2 of drive part 10.
During the cpu fan circuit working, monitor portion 20 records the current velocity of rotation of fan by the TACH signal frequency of lead-out terminal 3 outputs of drive part 10, and the PWM output of monitor portion 20 is adjusted the output of pwm signal automatically according to monitor portion 20 sensed temperature.When pwm signal is high level, transistor Q7 conducting among Fig. 1 make the emitter of transistor Q1 among Fig. 2 be in low level, so transistor Q1 is in saturation condition, the lead-out terminal 3 output TACH signals of transistor Q1 are low level, and voltage is greatly between 0 to 0.3V.
But, when pwm signal is low level, transistor Q7 among Fig. 1 is in cut-off state, make the emitter of transistor Q1 among Fig. 2 be in high level, therefore transistor Q1 is in cut-off state, this moment, fan inside was an equipotentiality body, and transistor Q1 output TACH signal is a high level, and voltage is greatly about 12V.And the voltage specification of the TACH input of monitor portion 20 is to surpass 6.0V, so the internal integrated circuit of monitor portion 20 is burnt in the design of available circuit through regular meeting.
[summary of the invention]
The purpose of this invention is to provide a kind of central processing unit fan circuit with overvoltage protection.
For realizing purpose of the present invention, the central processing unit fan circuit with overvoltage protection provided by the invention comprises: a monitor portion, and it comprises a tacho signal input and a pulse-width signal output; One drive part, it comprises a tacho signal output, and it links to each other with one first power supply terminal, and a first input end links to each other with a second source terminal, and second input; One transistor, its drain electrode are connected to second input of drive part, and source ground, grid are connected to the pulse-width signal output of monitor portion, and described pulse-width signal output is connected to described first power supply terminal by a pull-up resistor; Described central processing unit fan circuit with overvoltage protection also comprises a voltage stabilizing part; described voltage stabilizing partly is a diode; its negative electrode is connected to described first power supply terminal, and anode is connected to the node between the tacho signal input of the tacho signal output of drive part and monitor portion.
The central processing unit fan circuit that adopts the present invention to have overvoltage protection; its drive part is when monitor portion output TACH signal; its voltage stabilizing part can limit this TACH voltage of signals within the limits prescribed, thereby has ensured that monitor portion can operate as normal.
[description of drawings]
Fig. 1 is existing C PU fan circuit figure.
Fig. 2 is the internal circuit diagram of drive part among Fig. 1.
Fig. 3 has a preferred embodiment of the cpu fan circuit of overvoltage protection for the present invention.
Fig. 4 has another preferred embodiment of the cpu fan circuit of overvoltage protection for the present invention.
[embodiment]
The present invention have overvoltage protection the central processing unit fan circuit preferred embodiment as shown in Figure 3, it comprises a drive part 60, a monitor portion 70 and a diode D11.The lead-out terminal 31 outputs one TACH signal of drive part 60 is to the TACH input of monitor portion 70.Node between the TACH input of lead-out terminal 31 and monitor portion 70 is connected to first power supply terminal of 5V by a resistance R 11.Input terminal 21 is connected to the second source terminal of a 12V, is connected to the end of filter capacitor C11 simultaneously, the other end ground connection of filter capacitor C11.Input terminal 11 is connected to the drain electrode of transistor Q71, the direct ground connection of the source electrode of transistor Q71, the grid of transistor Q71 is connected to the PWM output of monitor portion 20 by a resistance R 21, and the node between resistance R 21 and the monitor portion 70 is connected to first power supply terminal of 5V by a pull-up resistor R31.The negative electrode of described diode D11 is connected to first power supply terminal of 5V, and anode is connected to the node between the TACH input of the lead-out terminal 31 of drive part 60 and monitor portion 20.
When the present invention had the central processing unit fan circuit work of overvoltage protection, when the lead-out terminal 31 output TACH signals of drive part 60 were low level, diode D11 reverse bias was in cut-off state, and the TACH input of monitor portion 70 is input as low level.Lead-out terminal 31 output TACH signals are voltage when being the high level of 12V, and diode D11 forward bias is in conducting state, and the TACH input of monitor portion 70 is clamped at about 5.7V.Like this, the input voltage of the TACH input of monitor portion 70 can not surpass its specification voltage 6V all the time, has ensured monitor portion 70 operate as normal and can not burnt out.
The present invention have overvoltage protection the central processing unit fan circuit another preferred embodiment as shown in Figure 4, it comprises a drive part 60, a monitor portion 70 and voltage stabilizing didoe D21.The burning voltage of described voltage stabilizing didoe D21 is 4V, its plus earth, and negative electrode is connected to the node between the TACH input of the lead-out terminal 31 of drive part 60 and monitor portion 70.Like this, the input voltage of the TACH input of monitor portion 70 is clamped at 4V all the time, can not surpass its specification voltage 6V.
Claims (4)
1. central processing unit fan circuit with overvoltage protection comprises:
One monitor portion, it comprises a tacho signal input and a pulse-width signal output;
One drive part, it comprises a tacho signal output, and it links to each other with one first power supply terminal, and a first input end links to each other with a second source terminal, and second input;
One transistor, its drain electrode are connected to second input of drive part, and source ground, grid are connected to the pulse-width signal output of monitor portion, and described pulse-width signal output is connected to described first power supply terminal by a pull-up resistor;
It is characterized in that: described central processing unit fan circuit with overvoltage protection also comprises a voltage stabilizing part; described voltage stabilizing partly is a diode; its negative electrode is connected to described first power supply terminal, and anode is connected to the node between the tacho signal input of the tacho signal output of drive part and monitor portion.
2. the central processing unit fan circuit with overvoltage protection as claimed in claim 1 is characterized in that: the first input end of described drive part links to each other with an end of a filter capacitor, the other end ground connection of this filter capacitor.
3. central processing unit fan circuit with overvoltage protection comprises:
One monitor portion, it comprises a tacho signal input and a pulse-width signal output;
One drive part, it comprises a tacho signal output, and it links to each other with one first power supply terminal, and a first input end links to each other with a second source terminal, and second input;
One transistor, its drain electrode are connected to second input of drive part, and source ground, grid are connected to the pulse-width signal output of monitor portion, and described pulse-width signal output is connected to described first power supply terminal by a pull-up resistor;
It is characterized in that: described central processing unit fan circuit with overvoltage protection also comprises a voltage stabilizing part; described voltage stabilizing partly is a voltage stabilizing didoe; its plus earth, negative electrode are connected to the node between the tacho signal input of the tacho signal output of drive part and monitor portion.
4. the central processing unit fan circuit with overvoltage protection as claimed in claim 3 is characterized in that: the first input end of described drive part links to each other with an end of a filter capacitor, the other end ground connection of this filter capacitor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2004100520680A CN100405735C (en) | 2004-10-30 | 2004-10-30 | CPU fan circuit with over-voltage protection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2004100520680A CN100405735C (en) | 2004-10-30 | 2004-10-30 | CPU fan circuit with over-voltage protection |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1767354A CN1767354A (en) | 2006-05-03 |
| CN100405735C true CN100405735C (en) | 2008-07-23 |
Family
ID=36743012
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2004100520680A Expired - Fee Related CN100405735C (en) | 2004-10-30 | 2004-10-30 | CPU fan circuit with over-voltage protection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100405735C (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103970230A (en) * | 2013-01-25 | 2014-08-06 | 昆达电脑科技(昆山)有限公司 | Protection device for hot-plugging fan |
| CN110285086B (en) | 2019-05-09 | 2020-09-04 | 苏州浪潮智能科技有限公司 | Fan control system, method and server |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040001542A1 (en) * | 2002-07-01 | 2004-01-01 | Miller Wayne A. | Method and apparatus for measuring the rotational speed of a fan |
| CN1474062A (en) * | 2002-08-07 | 2004-02-11 | 联想(北京)有限公司 | Method and device for closed-loop controlling cooling fan rotation speed according to CPU temperature |
| WO2004086835A1 (en) * | 2003-03-28 | 2004-10-07 | Siemens Aktiengesellschaft | Ventilation device |
-
2004
- 2004-10-30 CN CNB2004100520680A patent/CN100405735C/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040001542A1 (en) * | 2002-07-01 | 2004-01-01 | Miller Wayne A. | Method and apparatus for measuring the rotational speed of a fan |
| CN1474062A (en) * | 2002-08-07 | 2004-02-11 | 联想(北京)有限公司 | Method and device for closed-loop controlling cooling fan rotation speed according to CPU temperature |
| WO2004086835A1 (en) * | 2003-03-28 | 2004-10-07 | Siemens Aktiengesellschaft | Ventilation device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1767354A (en) | 2006-05-03 |
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| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20080723 Termination date: 20101030 |