CN204392087U - A kind of voltage stabilizing circuit - Google Patents
A kind of voltage stabilizing circuit Download PDFInfo
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- CN204392087U CN204392087U CN201520093030.1U CN201520093030U CN204392087U CN 204392087 U CN204392087 U CN 204392087U CN 201520093030 U CN201520093030 U CN 201520093030U CN 204392087 U CN204392087 U CN 204392087U
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Abstract
This application discloses a kind of voltage stabilizing circuit, comprise DC power supply, first switching tube, second switch pipe, pull-up resistor, first feedback resistance and the second feedback resistance, by the corrective action of second switch pipe to the first switching tube, make the voltage stabilization of the second feedback resistance at an occurrence, simultaneously because the first feedback resistance and total resistance of the second feedback resistance and the difference of voltage stabilizing circuit load resistance resistance exceed preset resistive value, therefore less by the electric current on the first feedback resistance and the second feedback resistance, negligible compared with load current, this also makes by the electric current on the first feedback resistance and the second feedback resistance less by the impact of load current, voltage on second feedback resistance is highly stable, thus output voltage is highly stable.
Description
Technical Field
The utility model relates to a steady voltage technical field, more specifically the theory relates to a voltage stabilizing circuit.
Background
The voltage stabilizing circuit is a circuit which can keep the output voltage constant when the input voltage, the load, the ambient temperature, the circuit parameters and the like are changed. The voltage stabilizing circuit can provide stable direct current power supply and is widely applied to various electronic devices.
Referring to fig. 1, in a circuit diagram of a voltage stabilizing circuit provided in the prior art, a resistor R and a zener diode D are connected in series between a dc power supply VB and a ground terminal, and a voltage at two ends of the zener diode D is an output voltage Vout. When the zener diode D breaks down in the reverse direction, the terminal voltage is almost unchanged within a certain current range (or within a certain power loss range), that is, the zener characteristic is exhibited, and therefore, the stability of the output voltage Vout can be ensured.
However, when the output load changes, the load current also changes correspondingly, so that the regulated voltage value of the zener diode also changes, and therefore, the voltage regulation precision of the conventional voltage stabilizing circuit is low.
SUMMERY OF THE UTILITY MODEL
In view of this, the present invention provides a voltage stabilizing circuit to improve the voltage stabilizing precision.
A voltage regulator circuit, comprising: the voltage regulator comprises a direct-current power supply, a first switch tube, a second switch tube, a pull-up resistor, a first feedback resistor and a second feedback resistor, wherein the difference value between the total resistance value of the first feedback resistor and the second feedback resistor and the resistance value of a load resistor of the voltage stabilizing circuit exceeds a preset resistance value;
the input end of the first switch tube is connected with the direct-current power supply, the output end of the first switch tube is connected with the ground end through the first feedback resistor and the second feedback resistor which are connected in series, and the terminal voltage of the output end of the first switch tube and the common end of the first feedback resistor is used as the output voltage of the voltage stabilizing circuit;
the input end of the second switch tube is connected with the control end of the first switch tube, the output end of the second switch tube is connected with the grounding end, and the control end of the second switch tube is connected with the common end of the first feedback resistor and the second feedback resistor;
one end of the pull-up resistor is connected with the direct-current power supply, and the other end of the pull-up resistor is connected with the control end of the first switch tube.
Preferably, the method further comprises the following steps: a voltage stabilizing capacitor;
and the positive plate of the voltage stabilizing capacitor is connected with the common end of the first switching tube and the first feedback resistor, and the negative plate of the voltage stabilizing capacitor is connected with the grounding end.
Preferably, the method further comprises the following steps: a thermistor;
one end of the thermistor is connected with the second switch tube and the common end of the first feedback resistor, and the other end of the thermistor is connected with the grounding end through the second feedback resistor.
Preferably, the thermistor is a negative temperature coefficient thermistor.
Preferably, the first switching tube is an NPN-type triode.
Preferably, the first switch tube is an NMOS tube.
Preferably, the second switching tube is an NPN-type triode.
Preferably, the second switch tube is an NMOS tube.
According to the above technical scheme, the utility model provides a voltage stabilizing circuit, including DC power supply, first switch tube, the second switch tube, pull-up resistance, first feedback resistance and second feedback resistance, when the control end opening voltage of voltage on the second feedback resistance surpassed the second switch tube, the second switch tube is opened, the control end voltage with first switch tube is drawn down, first switch tube is closed, output voltage reduces this moment, the voltage reduction on the second feedback resistance, the second switch tube is closed, the control end voltage of first switch tube risees, first switch tube is reopened, so relapse, the voltage is stabilized at the control end opening voltage of second switch tube on the final second feedback resistance. It can be seen that, the second switch tube is used for adjusting the first switch tube, so that the voltage of the second feedback resistor is stabilized at a specific value, and meanwhile, because the difference value between the total resistance value of the first feedback resistor and the second feedback resistor and the resistance value of the load resistor of the voltage stabilizing circuit exceeds the preset resistance value, the current passing through the first feedback resistor and the second feedback resistor is small and can be ignored compared with the load current, the influence of the load current on the current passing through the first feedback resistor and the second feedback resistor is small, the voltage on the second feedback resistor is very stable, so that the output voltage is very stable, compared with the prior art, the voltage stabilizing precision of the voltage stabilizing circuit is greatly improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
FIG. 1 is a circuit diagram of a voltage regulator circuit disclosed in the prior art;
fig. 2 is a circuit diagram of a voltage stabilizing circuit according to an embodiment of the present invention;
fig. 3 is a circuit diagram of another voltage regulator circuit according to an embodiment of the present invention;
fig. 4 is a circuit diagram of another voltage regulator circuit according to an embodiment of the present invention;
fig. 5 is a circuit diagram of another voltage regulator circuit according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
The embodiment of the utility model discloses voltage stabilizing circuit to realize the improvement of steady voltage precision.
Referring to fig. 2, an embodiment of the present invention discloses a circuit diagram of a voltage stabilizing circuit, the voltage stabilizing circuit includes: the difference value between the total resistance value of the direct-current power supply VB, the first switching tube Q1, the second switching tube Q2, the pull-up resistor R3, the first feedback resistor R1 and the second feedback resistor R2, and the resistance value of the load resistor of the voltage stabilizing circuit and the total resistance value of the first feedback resistor R1 and the second feedback resistor R2 exceeds a preset resistance value;
wherein,
the input end of the first switching tube Q1 is connected with a direct current power supply VB, the first feedback resistor R1 and the second feedback resistor R2 which are connected in series of the first switching tube Q1 are connected with the ground end, and the terminal voltage of the common end of the output end of the first switching tube Q1 and the first feedback resistor R1 is used as the output voltage Vout of the voltage stabilizing circuit;
the input end of the second switching tube Q2 is connected with the control end of the first switching tube Q1, the output end of the second switching tube Q2 is connected with the ground end, and the control end of the second switching tube Q2 is connected with the common end of the first feedback resistor R1 and the second feedback resistor R2;
one end of the pull-up resistor R3 is connected to the dc power supply VB, and the other end is connected to the control end of the first switch Q1.
The pull-up resistor R3 is used to open the first switch Q1, and the specific resistance depends on the actual requirement.
It should be noted that, since the total resistance of the first feedback resistor R1 and the second feedback resistor R2 is in parallel connection with the load resistor of the voltage regulator circuit, in order to ensure that the voltage across the second feedback resistor R2 is stable, the preset resistance needs to ensure that the currents across the first feedback resistor R1 and the second feedback resistor R2 are small and can be ignored compared with the load current. The specific value of the preset resistance value is determined according to actual needs, and the utility model discloses do not limit here.
The working principle of the voltage stabilizing circuit is as follows:
the output voltage Vout is divided by the first feedback resistor R1 and the second feedback resistor R2, the second switch tube Q2 collects the voltage on the second feedback resistor R2, when the voltage on the second feedback resistor R2 exceeds the control end opening voltage of the second switch tube Q2, the second switch tube Q2 is opened to pull down the control end voltage of the first switch tube Q1, the first switch tube Q1 is closed, at this time, the current flowing through a current path formed by the direct current power supply VB, the pull-up resistor R3, the control end and the output end of the first switch tube Q1, the first feedback resistor R1 and the second feedback resistor R2 is reduced, the output voltage Vout is reduced, the voltage on the second feedback resistor R2 is reduced, the second switch tube Q2 is closed, the control end voltage of the first switch tube Q1 is increased, and the first switch tube Q1 is opened again. By repeating the above steps, finally, the voltage across the second feedback resistor R2 is stabilized at the control terminal turn-on voltage Vbeo of the second switch Q2.
Since the voltage across the second feedback resistor R2 is generated by dividing the output voltage Vout through the first feedback resistor R1 and the second feedback resistor R2, Vbeo ═ Vout/(R1+ R2) × R2, so the stable value of the output voltage Vout is: vout ═ Vbeo × (R1+ R2)/R2, and since the control end turn-on voltage Vbeo of the second switching tube Q2, the first feedback resistor R1 and the second feedback resistor R2 are all fixed values, the voltage stabilizing circuit provided by the present application realizes voltage stabilization.
By matching different voltage dividing values of the first feedback resistor R1 and the second feedback resistor R2, the output voltage Vout can output different voltage values.
In summary, it can be seen that the voltage of the second feedback resistor R2 is stabilized at a specific value by the adjustment action of the second switching tube Q2 on the first switching tube Q1, and meanwhile, because the difference between the total resistance of the first feedback resistor R1 and the total resistance of the second feedback resistor R2 and the resistance of the load resistor of the voltage stabilizing circuit exceeds the preset resistance, the current passing through the first feedback resistor R1 and the second feedback resistor R2 is small and can be ignored compared with the load current, so that the current passing through the first feedback resistor R1 and the second feedback resistor R2 is less affected by the load current, and the voltage of the second feedback resistor R2 is very stable, so that the output voltage is very stable, and compared with the prior art, the voltage stabilizing precision of the voltage stabilizing circuit is greatly improved by the present application.
In addition, because the electrical elements adopted by the voltage stabilizing circuit provided by the application are all discrete elements, the voltage stabilizing circuit provided by the application has the advantages of easiness in implementation, low price and wide application range.
In order to further optimize the above embodiment, referring to fig. 2, a circuit diagram of a voltage stabilizing circuit according to another embodiment of the present invention further includes, on the basis of the embodiment shown in fig. 1: a voltage stabilizing capacitor C1;
the positive plate of the voltage-stabilizing capacitor C1 is connected with the common end of the first switch tube Q1 and the first feedback resistor R1, and the negative plate is connected with the grounding end.
When the output load changes, the voltage stabilizing circuit needs a certain time for adjustment, and at the moment, the voltage stabilizing capacitor C1 plays a role in stabilizing the voltage.
In order to better realize the stability of the voltage stabilizing circuit, on the basis of the above embodiment, the method further includes: a thermistor Rt;
one end of the thermistor Rt is connected to the common terminal of the second switch tube Q2 and the first feedback resistor R1, and the other end of the thermistor Rt is connected to the ground terminal through the second feedback resistor R2.
When the environment temperature of the voltage stabilizing circuit changes, the control end opening voltage Vbeo of the second switch tube Q2 changes along with the change of the temperature, so that the output voltage Vout deviates, after the second feedback resistor R2 is connected with a thermistor Rt in series, the thermistor Rt also changes along with the change of the temperature, so that the change of the control end opening voltage Vbeo of the second switch tube Q2 caused by the change of the temperature is counteracted, and the stability of the output voltage Vout can be still ensured under different environment temperatures of the voltage stabilizing voltage.
Since the control terminal turn-on voltage Vbeo of the second switch Q2 decreases with increasing temperature, it can be derived from the formula Vout ═ Vbeo × (R1+ R2)/R2 that, in order to ensure the output voltage Vout to be stable, the resistance of the second feedback resistor R2 must also decrease with increasing temperature, and therefore, the thermistor Rt adopts a negative temperature coefficient thermistor.
In the above embodiment, the first switch Q1 may be an NPN transistor or an NMOS transistor, and similarly, the second switch Q2 may be an NPN transistor or an NMOS transistor.
When the first switch transistor Q1 and the second switch transistor Q2 are both NPN transistors, the circuit diagram of the voltage regulator circuit is specifically shown in fig. 2 and 3.
When the first switch tube Q1 and the second switch tube Q2 are both NMOS tubes, the circuit diagram of the voltage regulator circuit is shown in fig. 4 and 5.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (8)
1. A voltage regulator circuit, comprising: the voltage regulator comprises a direct-current power supply, a first switch tube, a second switch tube, a pull-up resistor, a first feedback resistor and a second feedback resistor, wherein the difference value between the total resistance value of the first feedback resistor and the second feedback resistor and the resistance value of a load resistor of the voltage stabilizing circuit exceeds a preset resistance value;
the input end of the first switch tube is connected with the direct-current power supply, the output end of the first switch tube is connected with the ground end through the first feedback resistor and the second feedback resistor which are connected in series, and the terminal voltage of the output end of the first switch tube and the common end of the first feedback resistor is used as the output voltage of the voltage stabilizing circuit;
the input end of the second switch tube is connected with the control end of the first switch tube, the output end of the second switch tube is connected with the grounding end, and the control end of the second switch tube is connected with the common end of the first feedback resistor and the second feedback resistor;
one end of the pull-up resistor is connected with the direct-current power supply, and the other end of the pull-up resistor is connected with the control end of the first switch tube.
2. The voltage regulator circuit of claim 1, further comprising: a voltage stabilizing capacitor;
and the positive plate of the voltage stabilizing capacitor is connected with the common end of the first switching tube and the first feedback resistor, and the negative plate of the voltage stabilizing capacitor is connected with the grounding end.
3. The voltage regulator circuit of claim 1, further comprising: a thermistor;
one end of the thermistor is connected with the second switch tube and the common end of the first feedback resistor, and the other end of the thermistor is connected with the grounding end through the second feedback resistor.
4. The voltage regulator circuit of claim 3 wherein the thermistor is a negative temperature coefficient thermistor.
5. The voltage regulator circuit of claim 1, wherein the first switching transistor is an NPN transistor.
6. The voltage regulator circuit of claim 1, wherein the first switch transistor is an NMOS transistor.
7. The voltage regulator circuit of claim 1, wherein the second switching transistor is an NPN transistor.
8. The voltage regulator circuit according to claim 1, wherein the second switching transistor is an NMOS transistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520093030.1U CN204392087U (en) | 2015-02-10 | 2015-02-10 | A kind of voltage stabilizing circuit |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520093030.1U CN204392087U (en) | 2015-02-10 | 2015-02-10 | A kind of voltage stabilizing circuit |
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| Publication Number | Publication Date |
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| CN204392087U true CN204392087U (en) | 2015-06-10 |
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| CN201520093030.1U Active CN204392087U (en) | 2015-02-10 | 2015-02-10 | A kind of voltage stabilizing circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112533431A (en) * | 2020-12-04 | 2021-03-19 | 深圳市智仁科技有限公司 | Anti-loosening PCBA mainboard |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112533431A (en) * | 2020-12-04 | 2021-03-19 | 深圳市智仁科技有限公司 | Anti-loosening PCBA mainboard |
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Address after: 4 / F, building 1, No.14 Jiuxianqiao Road, Chaoyang District, Beijing 100020 Patentee after: Beijing Jingwei Hirain Technologies Co.,Inc. Address before: 100101 Beijing city Chaoyang District Anxiang Beili 11 B block 8 layer Patentee before: Beijing Jingwei HiRain Technologies Co.,Ltd. |
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| CP03 | Change of name, title or address |