CN1321995A - Current zero-crossing detection circuit of switching circuit - Google Patents
Current zero-crossing detection circuit of switching circuit Download PDFInfo
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- CN1321995A CN1321995A CN 00114549 CN00114549A CN1321995A CN 1321995 A CN1321995 A CN 1321995A CN 00114549 CN00114549 CN 00114549 CN 00114549 A CN00114549 A CN 00114549A CN 1321995 A CN1321995 A CN 1321995A
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- 238000001514 detection method Methods 0.000 title abstract description 7
- 238000000034 method Methods 0.000 description 14
- 238000010586 diagram Methods 0.000 description 4
- 238000011084 recovery Methods 0.000 description 2
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- 230000001276 controlling effect Effects 0.000 description 1
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Abstract
The present invention relates to a current zero-crossing detection circuit of switch circuit, in switch circuit, except middle point, at least one point of other three points of basic unit is connected with relatively-stable voltage source, it can be used as reference voltaqge source. It is characterized by that the said circuit equipment is formed from a comparator or logic gate circuit and several divider resistors connected with its input end, and two input ends of the comparator are connected to one reference voltage source and two ends of the middle point by means of two groups of divider resistors whose one end is grounded, and the input end of the logic gate circuit is connected to the middle point by means of one group of divider resistors whose one end is grounded so as to measure voltage signal of middle point current. Under the condition of that the voltage range of middle point and voltage range of comparator or logic circuit are compatible, the above-mentioned divider resistors can be saved.
Description
The present invention relates to a kind of current over-zero testing circuit device of switching circuit.
Switching circuit is through simplifying two kinds of switch elements that can obtain a, b as Fig. 1.In fact, two kinds of switch elements shown in Figure 1 can expand to switching circuit shown in a, the b as Fig. 2 respectively, in the elementary cell except that mid point C point, its excess-three point, have at least among A, P, the O a bit to be connected with metastable voltage source, any point that is connected with metastable voltage source can be as the reference voltage source of comparing with the C point.The current over-zero testing circuit of existing switching circuit has two kinds: a kind of is the resistance detection method, small resistor on promptly in main circuit, going here and there, detect current zero-crossing point by measuring ohmically voltage drop, because resistance causes loss in main circuit, therefore resistance value certainly will need very little, so just caused detection signal very weak, make that the anti-interference of control circuit is poor, in any case and resistance all can cause loss, in the application of low-voltage and high-current, this method is because loss is too big and impracticable.Because this resistance must be external, make the integrated very difficult of this method; Another kind method is the current transformer detection method, promptly in main circuit, introduce the method for current transformer (or being similar to Hall device), convert current signal to voltage signal, again this voltage signal is handled (methods such as existing average, peak value, electric charge), obtained the voltage signal that can be used for controlling.The shortcoming of the method be complicated, expensive, volume greatly, not easy of integration.In addition, more than a common drawback of two kinds of methods be to be insensitive for current zero-crossing point, more than the voltage signal that obtains of two kinds of methods all be (being similar to the ratio characteristic) of gradual change along with the variation of electric current, a strong signal can not be provided when current zero-crossing point, cause them can not detect current zero-crossing point very accurately.
Purpose of the present invention just provide a kind of simple, sensitive, be easy to integrated current over-zero testing circuit.
The object of the present invention is achieved like this, elementary cell is except that mid point C in the switching circuit, its excess-three point A, P, have at least any to be connected among the O with metastable voltage source, the any point that is connected with metastable voltage source can be as the reference voltage source of comparing with the C point, it is characterized in that this circuit arrangement is by a comparator, and several divider resistances that link to each other with its input are formed, two inputs of comparator are by two component piezoresistances of an end ground connection, be connected to the two ends of a reference voltage source and mid point C, in order to measure the voltage signal of mid point C electric current, perhaps this circuit arrangement is by a logic gates, and several divider resistances that link to each other with its input are formed, the input of logic gates is by a component piezoresistance of an end ground connection, be connected to mid point C, in order to measure the voltage signal of mid point C electric current.The situation of the voltage range of ordering for C and the voltage range compatibility of comparator or logical circuit, then above-mentioned divider resistance can save.
When the switch connection in the said switching circuit, inductance is recharged the generation forward current.Behind the certain hour, be subjected to outside control, switch disconnects.At this time, owing to have forward current in the inductance, make diode forward conducting afterflow, inductance bears counter voltage simultaneously, and its electric current reduces gradually, and when inductive current was reduced to zero, diode turn-offed naturally, and at this time the mid point C in the circuit can produce jump in potential.Convert this jump in potential to digital signal by comparator or logic gates, promptly can be used for detecting the zero crossing of electric current in the inductance.
The invention has the advantages that and only adopt comparator or logical device, make it can be easy to integrate with " gate drive circuit ", also can integrate with " feedback control circuit ", owing to voltage jump is arranged at current zero-crossing point, make this method can accurately detect current zero-crossing point very delicately, in addition, because the mid-point voltage saltus step occurs in after the reverse recovery of diode (or diode of switch body), therefore, this method can self adaptation be regulated the gate pole time-delay, reaches the purpose that makes two utmost point reverse recovery loss minimums automatically.
The a of Fig. 1, b are the switching circuit reduced graph.
The a of Fig. 2, b are that switching circuit is simplified expander graphs.
The a of Fig. 3, b, c, d, e, f select different reference voltage sources for use for a, the b at Fig. 2, and comparator circuit of the present invention detects the current over-zero circuit theory diagrams.
The a of Fig. 4, b select different reference voltage sources for use for a, the b at Fig. 2, and logic gates of the present invention detects the current over-zero circuit theory diagrams.
Fig. 5 connects the gate drive circuit schematic diagram for the present invention utilizes trigger.
Fig. 6, Fig. 7 are applied to the circuit theory diagrams of variable frequency control mode for the present invention.
But a of a of Fig. 8, b, Fig. 9, b are all kinds of switching circuit figure of the present invention's extensive use.
Below in conjunction with accompanying drawing embodiments of the invention are elaborated.
As shown in Figure 3, elementary cell is except that mid point C in the switching circuit, its excess-three point A, P, O have at least any to be connected with metastable voltage source, can be used as the reference voltage source of comparator, this current over-zero testing circuit device is by a comparator 1, and two groups of several divider resistances that link to each other with its input are formed.Shown in a, the f of Fig. 3, two inputs of comparator 1 are two component piezoresistances by an end ground connection, are connected to the two ends of reference voltage source O and mid point C, in order to the voltage signal of the electric current that measures mid point C; Shown in b, the d of Fig. 3, two inputs of comparator 1 are two component piezoresistances by an end ground connection, are connected to the two ends of reference voltage source P and mid point C, in order to the voltage signal of the electric current that measures mid point C; Shown in c, the e of Fig. 3, two inputs of comparator 1 are two component piezoresistances by an end ground connection, are connected to the two ends of reference voltage source A and mid point C, in order to the voltage signal of the electric current that measures mid point C.Promptly the voltage of ordering with O, P, A respectively is reference voltage, compare with the C point, adopt the method for electric resistance partial pressure that the voltage of main circuit is dropped to comparator acceptable scope, for the situation of main circuit voltage range and comparator voltage scope compatibility, these divider resistances can save.
Shown in a, the b of Fig. 4, if selected reference voltage be just " ", then above-mentioned comparator can further be reduced to logic gates, gate can be not gate or follower.This circuit arrangement is by a logic gates 2, and a component piezoresistance that links to each other with its input forms, and the input of logic gates 2 is connected to mid point C by a component piezoresistance of an end ground connection, in order to the voltage signal of the electric current that measures mid point C.
The voltage of mid point C in the circuit is often owing to the action of switch produces noise, and for avoiding the influence of noise to circuit, this signal need be for further processing, and just can be used as the control signal of switch.As shown in Figure 5, the output V of comparator 1 in the current over-zero testing circuit or logic gates 2
k, be and pulse-width signal V
bReceive on the gate drive circuit 4 by trigger or signal interlocking device 3, with the closure and the disconnection of switch (S1) in the control switch circuit, switching signal is carried out interlocking to reach elimination noise, jamproof purpose by trigger or signal interlocking device like this.
The present invention's's " bound current detection " method can be applicable to be operated in the variable frequency control mode of " bound current pattern ", promptly adopts the saltus step of switch, diode mid-point voltage to trigger " deciding pulse width control ".As shown in Figure 6, variable frequency control has " deciding service time " to reach " deciding the turn-off time " dual mode, and during current over-zero, the saltus step of mid-point voltage can be used as the triggering of " service time "; As shown in Figure 7, the current boundary working condition also can be used for the power factor correction circuit that variable frequency control " is decided service time ".
Electric current detecting method of the present invention can be applicable to a as Fig. 8, the switching circuit shown in the b, and they are widely used in " circuit of synchronous rectification " and reach in " bridge circuit ".For the circuit that A point or B point are connected with metastable voltage source, A point or B point can be used as reference voltage source, among a of Fig. 8 by detect S1 or S2 gate signal remove after the saltus step of C level point judge the direction of current source I.The direction of current source I1, I2 is judged in the level saltus step of ordering by C1 point or C2 after detection S1 or the removal of S2 gate signal among the b of Fig. 8.In some circuit application, as the C1 among the b of the point of the C among a of Fig. 8 or Fig. 8, voltage that C2 is ordered is metastable, and the voltage that A point and B are ordered is saltus step, should be reference voltage with C1, the C2 among the b of the point of the C among a of Fig. 8 or Fig. 8 at this time, by detect S1 or S2 gate signal remove after the saltus step of A point or B level point judge the current source I1 among the b of current source I among a of Fig. 8 or Fig. 8, the direction of I2.
Electric current detecting method of the present invention can be applicable to a as Fig. 9, the switching circuit shown in the b, and they are widely used in " circuit of synchronous rectification ".In these two kinds of switch elements, also can be by detecting after S1, S2 gate signal remove, the voltage jump that A point or B orders, thus judgement illustrate in the direction of current source I, thereby reach the purpose of current detecting.
Claims (6)
1. the current over-zero testing circuit device of a switching circuit, elementary cell is except that mid point (C) in the switching circuit, its excess-three point (A, P, O) having any at least is to be connected with metastable voltage source, can be used as reference voltage source, it is characterized in that this circuit arrangement is by a comparator (1) or logic gates (2), and several divider resistances that link to each other with its input are formed, two inputs of comparator (1) are by two component piezoresistances of an end ground connection, be connected to the two ends of a reference voltage source and mid point (C point), the input of logic gates (2) is by a component piezoresistance of an end ground connection, be connected to mid point (C point), in order to measure the voltage signal of mid point (C point) electric current, the situation of the voltage range of ordering for C and the voltage range compatibility of comparator (1) or logic gates (2), then above-mentioned divider resistance can save.
2. according to comparator (1) in the described current over-zero testing circuit of claim 1 or logic gates (2), it is characterized in that its output signal (Vk) and pulse-width signal (Vb) are connected on the gate drive circuit (4) by trigger or signal interlocking device (3), with the closure and the disconnection of switch (S1) in the control switch circuit.
3. according to the comparator (1) in the described current over-zero testing circuit of claim 1, it is characterized in that the two component piezoresistances of two input by an end ground connection, be connected to the two ends of a reference voltage source (O point) and mid point (C point), to measure the voltage signal of mid point (C point) electric current.
4. according to the comparator (1) in the described current over-zero testing circuit of claim 1, it is characterized in that the two component piezoresistances of two input by an end ground connection, be connected to the two ends of a reference voltage source (P point) and mid point (C point), to measure the voltage signal of mid point (C point) electric current.
5. according to the comparator (1) in the described current over-zero testing circuit of claim 1, it is characterized in that the two component piezoresistances of two input by an end ground connection, be connected to the two ends of a reference voltage source (A point) and mid point (C point), to measure the voltage signal of mid point (C point) electric current.
6. according to the logic gates (2) in the described current over-zero testing circuit of claim 1, it is characterized in that the component piezoresistance of its input, be connected to mid point (C point), to measure the voltage signal of mid point (C point) electric current by an end ground connection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB001145495A CN1163925C (en) | 2000-04-30 | 2000-04-30 | Current zero-crossing detection circuit of switching circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB001145495A CN1163925C (en) | 2000-04-30 | 2000-04-30 | Current zero-crossing detection circuit of switching circuit |
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| Publication Number | Publication Date |
|---|---|
| CN1321995A true CN1321995A (en) | 2001-11-14 |
| CN1163925C CN1163925C (en) | 2004-08-25 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB001145495A Expired - Fee Related CN1163925C (en) | 2000-04-30 | 2000-04-30 | Current zero-crossing detection circuit of switching circuit |
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| CN (1) | CN1163925C (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104092388A (en) * | 2014-06-17 | 2014-10-08 | 昆山弗尔赛能源有限公司 | Synchronous rectifying BOOST circuit with reverse current prevention |
| CN108490246A (en) * | 2012-12-21 | 2018-09-04 | 密克罗奇普技术公司 | Supply voltage zero-crossing detector |
| CN114070174A (en) * | 2020-07-30 | 2022-02-18 | 深圳市合广测控技术有限公司 | Opening and closing time adjusting method, opening and closing time adjusting device, terminal and storage medium |
-
2000
- 2000-04-30 CN CNB001145495A patent/CN1163925C/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108490246A (en) * | 2012-12-21 | 2018-09-04 | 密克罗奇普技术公司 | Supply voltage zero-crossing detector |
| CN108490246B (en) * | 2012-12-21 | 2021-07-30 | 密克罗奇普技术公司 | Power supply voltage zero-crossing detector |
| CN104092388A (en) * | 2014-06-17 | 2014-10-08 | 昆山弗尔赛能源有限公司 | Synchronous rectifying BOOST circuit with reverse current prevention |
| CN114070174A (en) * | 2020-07-30 | 2022-02-18 | 深圳市合广测控技术有限公司 | Opening and closing time adjusting method, opening and closing time adjusting device, terminal and storage medium |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1163925C (en) | 2004-08-25 |
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Owner name: JOULWATT MICROELECTRONICS (SUZHOU) CO., LTD. Free format text: FORMER OWNER: HUANG BIWU Effective date: 20140520 |
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Effective date of registration: 20140520 Address after: Hangzhou City, Zhejiang province Yuhang District 311121 West Street warehouse before No. 1500 Building 1 room 424 Patentee after: Jevat Microelectronics (Hangzhou) Co., Ltd. Address before: 350009 Fujian city of Fuzhou province Shuangfeng quanta road building 9G easy computer Monitor Company Patentee before: Huang Biwu |
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