CN104656035A - Detection and switching circuit of low-power power supply - Google Patents
Detection and switching circuit of low-power power supply Download PDFInfo
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- CN104656035A CN104656035A CN201310587505.8A CN201310587505A CN104656035A CN 104656035 A CN104656035 A CN 104656035A CN 201310587505 A CN201310587505 A CN 201310587505A CN 104656035 A CN104656035 A CN 104656035A
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Abstract
The invention discloses a detection and switching circuit of a low-power power supply. The detection and switching circuit comprises a first analog switch (U1), a second analog switch (U2), a micro processing unit (MCU), a comparator (V1), a first resistor (R1), a second resistor (R2), a third resistor (R3), a first input port (1), a second input port (2), a positive output port (3) and a negative output port (4); when the circuit works, polarity of an input power supply is detected through power supply detection, so that a back-stage circuit is controlled to be switched and the power supply obtained by a load is always kept consistent in polarity. The detection and switching circuit is simple in structure and low in cost, can well adapt to various places powered by the low-power power supply, can guarantee that no bad consequence caused by reverse polarity occurs in a using process, and can output the power supply in an amplitude-limiting mode.
Description
Technical field
The invention belongs to circuit protection technical field; relate to a kind of small-power power to detect and commutation circuit; be applicable to various analog and digital circuit power inlet; structure of the present invention is simple, with low cost; the place that various small-power power is powered can well be adapted to; can ensure to there will not be in the process used to cause adverse consequences because of error-polarity connection, simultaneously can amplitude limit out-put supply.
Background technology
In the performance history of all electronic equipments or product, power supply is absolutely necessary ingredient, is also the composition that frequency of utilization is the highest, and especially at exploitation and test phase, break-make power supply is absolutely necessary process frequently.Connecting power supply frequently and removing in the process of power supply; inevitably there will be the situation of power lead reversal connection; namely the both positive and negative polarity of power lead is connect instead by mistake; if circuit does not have enough safeguard measures, late-class circuit or power supply will be burnt, also or occur that power supply and late-class circuit burn simultaneously; cause device and waste of time; extend the development time, improve cost of development, sometimes even can cause potential safety hazard.
It is now conventional that to prevent the method for reverse power connection from mainly containing following several: 1, anti-reverse plug-in unit; This method is the minimum also the most frequently used method of the simplest cost, but is generally use as finished product, because be difficult to separately after the occlusion of this connector, for needing the exploitation place often split to be inconvenient; 2, the reversal connection diode of power inlet; This method is through conventional method in exploitation, but this protection circuit can only protect late-class circuit, and design philosophy selects to sacrifice power supply, do not have obvious warning device, easily burn power supply; 3, protective tube; Although can protection circuit to a great extent, change trouble, simultaneously for Sensitive Apparatus, protected effect be not obvious; 4, self-protection circuit; This circuit generally designs at power end, and against short-circuit situation is cut off the electricity supply output, is generally the self-protection circuit doing circuit.
These circuit protection methods respectively have oneself application; but but all well can not accomplish protection front and back end circuit; for this situation; a kind of small-power power of the present invention detects and commutation circuit; during circuit working, first by power detecting, detect the polarity of input power; thus control late-class circuit switches, the power supply that load is obtained remains that polarity is consistent.Structure of the present invention is simple, with low cost, can well adapt to the place that various small-power power is powered, and can ensure to there will not be in the process used to cause adverse consequences because of error-polarity connection, simultaneously can amplitude limit out-put supply.
Summary of the invention
The object of the invention is to design a kind of small-power power detect and commutation circuit, before power supply is connected, first detected the polarity of access power supply by power sense circuit; according to testing result; switching analoging switch, thus the polarity ensureing out-put supply, can well protection circuit.
Technical scheme of the present invention is: a kind of small-power power detects and commutation circuit, is made up of the first analog switch, the second analog switch, processor, comparer, the first resistance, the second resistance, the 3rd resistance, first input end mouth, the second input port, positive output port, negative output port; Wherein, first input end mouth is connected with a certain input port of the second analog switch with the first analog switch simultaneously, and the second input port is connected with a certain input port of the second analog switch with the first analog switch simultaneously; First resistance, the second resistance, the 3rd resistant series, one end is connected with first input end mouth, and one end is connected with the second input port in addition; Two junctions in the middle of three resistance of series connection are connected with negative input end with the positive input terminal of comparer respectively; The output terminal of comparer is connected with processor pin; First analog switch is connected with the pin of processor respectively with the control pin of the second analog switch; The output of the first analog switch is connected with positive output port, and the output terminal of the second analog switch is connected with negative output port.
Above-mentioned a kind of small-power power detects and commutation circuit, and it is characterized in that the first resistance, the second resistance, the 3rd resistance is three resistance that resistance is identical, resistance is more than 1 megohm.
Above-mentioned a kind of small-power power detects and commutation circuit, it is characterized in that the internal switch of the first analog switch and the second analog switch controls to control by processor.
Above-mentioned a kind of small-power power detects and commutation circuit, it is characterized in that first input end mouth and the second input port do not need to distinguish positive-negative polarity, by power sense circuit during system works, determines inner connection, thus can play anti-reverse effect.
Above-mentioned a kind of small-power power detects and commutation circuit, it is characterized in that the power supply of the first analog switch and the second analog switch can according to practical power Voltage Cortrol, thus make circuit can adapt to higher voltage range.
Above-mentioned a kind of small-power power detects and commutation circuit, it is characterized in that the first analog switch and the second analog switch can be no more than power itself voltage by restricted passage voltage, so the effect of circuit also Finite Amplitude.
Principle of work of the present invention is: by plant-grid connection between first input end mouth and the second input port, circuit is started working; First, by power sense circuit, i.e. resistance and comparator circuit, detects the positive-negative polarity of access power supply; Testing result is received by processor, processor according to testing result, to the first analog switch and the second analog switch sending controling instruction; Two path analoging switch by instruction commutation circuit annexation, thus ensure that the polarity of out-put supply.
Accompanying drawing explanation
Below in conjunction with design drawing, the invention will be further described:
Fig. 1 is the schematic diagram of a kind of small-power power detection of the present invention and commutation circuit;
In Fig. 1: U1, the first analog switch (U1); U2, the second analog switch; MCU, processor; V1, comparer; R1, the first resistance; R2, the second resistance; R3, the 3rd resistance; 1, first input end mouth; 2, the second input port; 3, positive output port; 4, negative output port.
Embodiment
Be the schematic diagram of a kind of small-power power detection of the present invention and commutation circuit as shown in Figure 1, comprise: the first analog switch U1, the second analog switch U2, processor MCU, comparer V1, the first resistance R1, the second resistance R2, the 3rd resistance R3, first input end mouth 1, second input port 2, positive output port 3, negative output port 4; Wherein, first input end mouth 1 is connected with a certain input port of the second analog switch U2 with the first analog switch U1 simultaneously, and the second input port 2 is connected with a certain input port of the second analog switch U2 with the first analog switch U1 simultaneously; First resistance R1, the second resistance R2, the 3rd resistance R3 connect, and one end is connected with first input end mouth 1, and one end is connected with the second input port 2 in addition; Two junctions in the middle of three resistance R1, R2, R3 of series connection are connected with negative input end with the positive input terminal of comparer V1 respectively; The output terminal of comparer V1 is connected with processor MCU pin; First analog switch U1 is connected with the pin of processor MCU respectively with the control pin of the second analog switch U2; The output of the first analog switch U1 is connected with positive output port 3, and the output terminal of the second analog switch U2 is connected with negative output port 4.
First resistance R1, the second resistance R2, the 3rd resistance R3 are three resistance that resistance is identical, when first input end mouth 1 inputs positive supply, when second input port 2 inputs negative supply, the voltage of the positive input terminal of comparer V1 higher than negative input end, thus will export high level; Otherwise, by output low level; The output voltage of processor MCU detection comparator V1 can judge power input status, thus sends corresponding steering order; Resistance is more than 1 megohm, and we select the resistance of 3 resistance R1, R2, R3 to be 2M here, reduces loss current.
The internal switch of the first analog switch U1 and the second analog switch U2 controls to control by processor MCU, here the analog switch that we select is CD4051, there are three control ports, 8 switchable ports, the power supply of the first analog switch U1 and the second analog switch U2 can according to practical power Voltage Cortrol, thus make circuit can adapt to higher voltage range; First analog switch U1 and the second analog switch U2 can be no more than power itself voltage by restricted passage voltage, so the effect of circuit also Finite Amplitude; MCU selects the MSP430 single-chip microcomputer of TI company, low in energy consumption.
First input end mouth 1 and the second input port 2 do not need to distinguish positive-negative polarity, by power sense circuit during system works, determine inner connection, thus can play anti-reverse effect.
During work, by plant-grid connection between first input end mouth 1 and the second input port 2, circuit is started working; First, by power sense circuit, i.e. resistance R1, R2, R3 and comparer V1 circuit, detects the positive-negative polarity of access power supply; Testing result is received by processor MCU, processor MCU according to testing result, to the first analog switch U1 and the second analog switch U2 sending controling instruction; Two path analoging switch by instruction commutation circuit annexation, thus ensure that the polarity of out-put supply.
Above embodiment is only illustrate reference of the present invention, do not form any restriction to content of the present invention, obviously under thought of the present invention, can make multi-form structure modify, but these is all at the row of protection of the present invention.
Claims (6)
1. small-power power detects and a commutation circuit, it is characterized in that comprising: the first analog switch (U1), the second analog switch (U2), processor (MCU), comparer (V1), the first resistance (R1), the second resistance (R2), the 3rd resistance (R3), first input end mouth (1), the second input port (2), positive output port (3), negative output port (4); Wherein, first input end mouth (1) is connected with a certain input port of the first analog switch (U1) with the second analog switch (U2) simultaneously, and the second input port (2) is connected with a certain input port of the first analog switch (U1) with the second analog switch (U2) simultaneously; First resistance (R1), the second resistance (R2), the 3rd resistance (R3) series connection, one end is connected with first input end mouth (1), and one end is connected with the second input port (2) in addition; Two junctions in the middle of three resistance (R1, R2, R3) of series connection are connected with negative input end with the positive input terminal of comparer (V1) respectively; The output terminal of comparer (V1) is connected with a pin of processor (MCU); First analog switch (U1) is connected with the pin of processor (MCU) respectively with the control pin of the second analog switch (U2); The output of the first analog switch (U1) is connected with positive output port (3), and the output terminal of the second analog switch (U2) is connected with negative output port (4).
2. a kind of small-power power according to claim 1 detects and commutation circuit, and it is characterized in that the first resistance (R1), the second resistance (R2), the 3rd resistance (R3) is identical three resistance of resistance, resistance is more than 1 megohm.
3. a kind of small-power power according to claim 1 detects and commutation circuit, it is characterized in that the internal switch of the first analog switch (U1) and the second analog switch (U2) controls to control by processor (MCU).
4. a kind of small-power power according to claim 1 detects and commutation circuit, it is characterized in that first input end mouth (1) and the second input port (2) do not need to distinguish positive-negative polarity, power sense circuit is passed through during system works, determine inner connection, thus anti-reverse effect can be played.
5. a kind of small-power power according to claim 1 detects and commutation circuit, it is characterized in that the power supply of the first analog switch (U1) and the second analog switch (U2) can according to practical power Voltage Cortrol, thus make circuit can adapt to higher voltage range.
6. a kind of small-power power according to claim 5 detects and commutation circuit, it is characterized in that the first analog switch (U1) and the second analog switch (U2) can be no more than power itself voltage by restricted passage voltage, so the effect of circuit also Finite Amplitude.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310587505.8A CN104656035A (en) | 2013-11-21 | 2013-11-21 | Detection and switching circuit of low-power power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310587505.8A CN104656035A (en) | 2013-11-21 | 2013-11-21 | Detection and switching circuit of low-power power supply |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104656035A true CN104656035A (en) | 2015-05-27 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310587505.8A Withdrawn CN104656035A (en) | 2013-11-21 | 2013-11-21 | Detection and switching circuit of low-power power supply |
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| CN (1) | CN104656035A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105552876A (en) * | 2015-12-28 | 2016-05-04 | 惠州华阳通用电子有限公司 | Signal automatic identifying and switching method and apparatus |
| CN112965012A (en) * | 2021-02-25 | 2021-06-15 | 广州亚美智造科技有限公司 | Power supply polarity reverse connection testing device, testing system and testing method |
| CN114236284A (en) * | 2021-12-14 | 2022-03-25 | 北京机电工程研究所 | Electrical testing device for aircraft |
-
2013
- 2013-11-21 CN CN201310587505.8A patent/CN104656035A/en not_active Withdrawn
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105552876A (en) * | 2015-12-28 | 2016-05-04 | 惠州华阳通用电子有限公司 | Signal automatic identifying and switching method and apparatus |
| CN112965012A (en) * | 2021-02-25 | 2021-06-15 | 广州亚美智造科技有限公司 | Power supply polarity reverse connection testing device, testing system and testing method |
| CN114236284A (en) * | 2021-12-14 | 2022-03-25 | 北京机电工程研究所 | Electrical testing device for aircraft |
| CN114236284B (en) * | 2021-12-14 | 2023-09-08 | 北京机电工程研究所 | Electrical testing device for aircraft |
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| C06 | Publication | ||
| PB01 | Publication | ||
| C04 | Withdrawal of patent application after publication (patent law 2001) | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20150527 |