CN102957324A - Power detection circuit - Google Patents
Power detection circuit Download PDFInfo
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- CN102957324A CN102957324A CN2012104812292A CN201210481229A CN102957324A CN 102957324 A CN102957324 A CN 102957324A CN 2012104812292 A CN2012104812292 A CN 2012104812292A CN 201210481229 A CN201210481229 A CN 201210481229A CN 102957324 A CN102957324 A CN 102957324A
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Abstract
The invention relates to a power detection circuit which comprises a switch power supply and a switch power transformer, wherein the switch power supply comprises a switch power chip; the switch power chip can control winding polarity switching of the switch power transformer according to the switch-on/off of an inner switch pipe; the switch power transformer comprises a primary winding, an auxiliary winding and a secondary winding; the secondary winding comprises a main output winding and a detecting winding; the first ends of the primary winding and the detecting winding and the second ends of the auxiliary winding and the main output winding are dotted terminals; the voltages at the two ends of the primary winding are in direct proportion to the detecting winding; the auxiliary winding is connected with a feedback end of the switch power chip; the detecting winding is connected with a detection circuit; the detection circuit is connected with a detection controller, namely, a single chip, for detecting; and the primary winding is isolated from the secondary winding. According to the power detection circuit, the primary winding and the secondary winding are manufactured in an isolated form, so that the strong and weak electrical isolation is realized; the power detection circuit is safe and practical; the wound circles of a winding for detecting an electric supply voltage are few; a wire diameter is small; the cost is low; and the manufacturing and production are convenient.
Description
Technical field
The present invention relates to a kind of testing circuit, particularly relate to a kind of power sense circuit.
Background technology
Present line voltage detects and mainly utilizes resistor network to carry out transforming by modulus (A/D) after the dividing potential drop, releases the line voltage value; Or isolate by Industrial Frequency Transformer, according to the operation principle of transformer, carry out again rectification, filtering is carried out dividing potential drop by resistor network again, by modulus (A/D) conversion, extrapolates line voltage at last.The former, although cost is low, because strong and weak electricity is not isolated, fail safe is bad; Although the latter adopts the Industrial Frequency Transformer of the isolation of safety, its cost is high, and power consumption is large.
Summary of the invention
Based on this, be necessary to provide a kind of power sense circuit that can improve fail safe.
A kind of power sense circuit, comprise: Switching Power Supply, and the switching mode power supply transformer that is connected with described Switching Power Supply, described Switching Power Supply comprises: switching power source chip, and described switching power source chip carries out the polarity conversion according to the conducting of internal switch pipe or the winding of cut-off control switch power transformer; Described switching mode power supply transformer comprises: armature winding, auxiliary winding, and secondary winding, described secondary winding comprises: main output winding, detect the detection winding of input power, the first end of described armature winding, the second end of auxiliary winding, the second end of main output winding, the first end that detects winding is Same Name of Ends, the voltage at described armature winding two ends is proportional to described detection winding both end voltage, described auxiliary winding is linked into the feedback end of switching power source chip, described detection winding is connected with testing circuit, described testing circuit is linked into and detects in the control device input power is carried out voltage detecting, described armature winding and secondary winding isolation.
In a preferred embodiment, described switching power source chip compares according to the feedback current of described auxiliary winding, adjusts the conducting duty ratio of internal switch pipe so that secondary winding obtains stable power supply; Described switching power source chip is assisted winding or main separately its latter linked auxiliary winding circuit or main cut-off and the conducting of exporting winding circuit or detecting winding circuit of exporting winding or detecting winding according to conducting or the cut-off control of internal switch pipe.
In a preferred embodiment, control the conducting of described detection winding circuit or disconnection described switching power source chip switching tube operating state with control described auxiliary winding circuit opposite; Described Switching Power Supply basis is adjusted frequency or the duty ratio of this Switching Power Supply automatically by the loading condition of the load circuit of the power output end connection of described main output winding, to adjust the main output voltage of exporting the power output end of winding.
In a preferred embodiment, described auxiliary winding connects thereafter auxiliary winding circuit and is provided with diode D2, capacitor C E2, described auxiliary winding output through diode D2 rectification, and capacitor C E2 filtering after obtain DC power supply, and power supply is to switching power source chip; Described diode D2 is arranged between the first end and described capacitor C E2 of described auxiliary winding, to pass through diode D2 with cut-off and the conducting of control connection in described auxiliary winding auxiliary winding circuit thereafter; The main output winding circuit that described main output winding connects thereafter setting is provided with diode D3, capacitor C E3, and the output of described main output winding is through diode D3 rectification, and capacitor C E3 filtering; Described diode D3 is arranged between the first end and described capacitor C E3 of described main output winding, to be arranged at conducting and the cut-off of described main output winding main output winding circuit thereafter by diode D3 control connection; The detection winding circuit that described detection winding connects thereafter setting is provided with diode D4, capacitor C 2, and described detection winding output obtains DC power supply after diode D4 rectification, capacitor C 2 filtering; Described diode D4 is arranged between the first end and described capacitor C 2 of described detection winding, to be arranged on conducting and the cut-off of described detection winding detection winding circuit thereafter with control connection by diode D4.
In a preferred embodiment, described capacitor C E3 two ends are parallel with LC circuit, described LC circuit comprises: the inductance L 1, the capacitor C E4 that connect successively, described main output winding out-put supply through behind diode D3, the capacitor C E3 rectifying and wave-filtering, again through inductance L 1 filtering, and capacitor C E4 again after the filtering output DC source power the common end grounding of described capacitor C E4 and capacitor C E3 to load circuit; The first end of described auxiliary winding accesses the positive pole of described diode D2, and the first end of described main output winding is connected with the positive pole of described diode D3, and the first end of described detection winding is connected with the positive pole of described diode D4.
In a preferred embodiment, be linked into the source electrode of described switching power source chip after the voltage stabilizing didoe ZD1 that another branch road access of the negative pole output of described diode D2 connects successively, the capacitor C 1, the negative pole of described voltage stabilizing didoe ZD1 is connected with the negative pole of described diode D2, and the common port of described voltage stabilizing didoe ZD1 and capacitor C 1 accesses the feedback end of described switching power source chip.
In a preferred embodiment, the common port of described diode D2 and capacitor C E2 is exported the operating voltage end that another branch road is linked into described switching power source chip, and the drain electrode of described switching power source chip is linked into the second end of described armature winding; Described capacitor C 2 is linked into second end of assisting winding with the common port that detects winding by capacitor C Y1 is set.
In a preferred embodiment, described testing circuit comprises: interconnective divider resistance R1, and detect resistance R 2, described divider resistance R1 is linked into to detect in the control device with the common port that detects resistance R 2 and changes, calculates; Described detection resistance R 2 two ends are parallel with capacitor C 3, detect the common end grounding of resistance R 2 and capacitor C 3; After described divider resistance R1 connects with described detection resistance R 2 and described capacitor C 2 in parallel; Described main output winding, detect winding and be winding independently.
In a preferred embodiment, also comprise rectification, filter circuit, described filter circuit comprises: filter capacitor CE1, the first input end of described rectification circuit, the second input are linked into respectively two outputs of input power, and the first output of described rectification circuit is linked into the first end of described armature winding; Another branch road of the first output of described rectification circuit is after the second output of filter capacitor CE1 and described rectification circuit converges, and wherein a branch road is linked into the source electrode of described switching power source chip, the second end that its another branch road is linked into described auxiliary winding; The common end grounding of the second end of described capacitor C E2 and described auxiliary winding.
In a preferred embodiment, the two ends of described armature winding are parallel with diode D1 and the transition twin zener dioder TVS1 that connects successively, the positive pole of described transition twin zener dioder TVS1 is linked into the first end of described armature winding, and the negative pole of described transition twin zener dioder TVS1 is connected and accesses by positive pole the second end of described armature winding with the negative pole of described diode D1.
In a preferred embodiment, the two ends of described armature winding are parallel with diode D1 and the transition twin zener dioder TVS1 that connects successively, the positive pole of described transition twin zener dioder TVS1 is linked into the first end of described armature winding, and the negative pole of described transition twin zener dioder TVS1 is connected and accesses by positive pole the second end of described armature winding with the negative pole of described diode D1.
Above-mentioned power sense circuit is made the isolation of armature winding and auxiliary winding, realizes the strong and weak electricity isolation, and is safe and practical, for detection of the winding of line voltage around the number of turns generally seldom, and wire diameter is thin again, cost is low, and makes convenient for production.
Switching power source chip is started working, armature winding is because of vicissitudinous electric current, operation principle according to transformer, other windings of switching mode power supply transformer i.e. auxiliary winding, main output winding, detection winding also will produce induced electromotive force, auxiliary winding is linked into the feedback end of switching power source chip, switching power source chip can carry out inside relatively with the feedback current according to auxiliary winding, adjust the conducting duty ratio of internal switch pipe, so that secondary winding obtains stable power supply.
Description of drawings
Fig. 1 is the schematic diagram of the power sense circuit of one embodiment of the invention.
Embodiment
As shown in Figure 1, the power sense circuit of one embodiment of the invention comprises: Switching Power Supply, and the switching mode power supply transformer TF1 that is connected with Switching Power Supply.
The Switching Power Supply of the present embodiment comprises: switching power source chip U1.Switching power source chip U1 is according to conducting or the cut-off of internal switch pipe, carries out polarity with the winding of control switch power transformer TF1 and transforms.
Further, the switching mode power supply transformer TF1 of the present embodiment comprises: armature winding N1, auxiliary winding N2, and secondary winding.Further, the secondary winding of the present embodiment comprises: the detection winding N4 of main output winding N3, detection input power.
Further, the power sense circuit of the present embodiment also comprises: the auxiliary winding circuit that is connected with auxiliary winding N2 and is powered by auxiliary winding N2, the detection winding circuit that is connected with main output winding N3 and is connected by the main output winding circuit of main output winding N3 power supply, with detection winding N4 and powered by detection winding N4.
Further, in the present embodiment, the first end of armature winding N1 is that the second end of 1 pin, auxiliary winding N2 is that 5 pin, main the second end of exporting winding N3 are that 9 pin, the first end that detects winding N4 are that 6 pin are Same Name of Ends.
Further, in the present embodiment, the voltage at armature winding N1 two ends is proportional to and detects winding N4 both end voltage.The voltage that is armature winding N1 two ends is directly proportional with the coil of this two winding with the ratio that detects winding N4 both end voltage.
The auxiliary winding N2 of the present embodiment or main output winding N3 or detect auxiliary winding circuit or the main output winding circuit that each group of winding N4 connects or detect winding circuit and end control with conducting according to the conducting of the switching tube of switching power source chip or cut-off.
During such as the cut-off of the switching tube of switching power source chip, auxiliary winding N2 or main output winding its latter linked auxiliary winding circuit of N3 or the conducting of main output winding circuit, auxiliary winding N2 or main output winding N3 power on auxiliary winding circuit or the main output winding circuit load being set, and the element that discharges and recharges is separately charged.
Further, the switch tube working status of the switching power source chip U1 of the main cut-off of exporting winding circuit that is used for that auxiliary winding circuit that the auxiliary winding N2 of control connects and main output winding N3 connect of the present embodiment and conducting is consistent.
Further, the present embodiment be used for control detect the detection winding circuit that winding N4 connects switching power source chip U1 switching tube operating state be used for the auxiliary winding circuit of control or mainly export the opposite of winding circuit.
Further, the detection winding N3 two ends of the present embodiment also are parallel with for the testing circuit that input power is carried out voltage detecting.
Further, assist winding N2 to connect thereafter auxiliary winding circuit and be provided with diode D2, capacitor C E2.Auxiliary winding N2 out-put supply through diode D2 rectification, and capacitor C E2 filtering after obtain DC power supply, and power supply is to switching power source chip U1.The first end that diode D2 is arranged on auxiliary winding N2 is between 4 pin and the capacitor C E2, with cut-off and the conducting by the auxiliary winding circuit of diode D2 one-way conduction Characteristics Control.
Further, the conducting of the switching tube of switching power source chip U1 or cut-off are changed with the polarity of controlling auxiliary winding N2, thus cut-off and the conducting of control diode D2.
Further, the positive pole of the i.e. 4 pin access of the first end of auxiliary winding N2 diode D2, the negative pole output of diode D2 is linked among the capacitor C E2.
Further, the main output winding N3 main output winding circuit that connects thereafter setting is provided with diode D3, capacitor C E3.The output of main output winding through diode D3 rectification, and capacitor C E3 filtering after the output DC source.The first end that diode D3 is arranged on main output winding N3 is between 10 pin and the capacitor C E3, with conducting and the cut-off of exporting winding circuit by diode D3 one-way conduction Characteristics Control master.
Further, the conducting of the switching tube of switching power source chip U1 or cut-off are changed with the polarity of controlling main output winding N3, thus cut-off and the conducting of control diode D3.
Further, main output winding circuit also comprises: the LC circuit that is connected in parallel with capacitor C E3 two ends.LC circuit comprises: the inductance L 1, the capacitor C E4 that connect successively.The out-put supply of main output winding after diode D3 rectification, capacitor C E3 filtering, again through inductance L 1 further filtering, and capacitor C E4 again after the further filtering output DC source power to load circuit.
Inductance L 1 is pooled to power output end VCC with the common port of capacitor C E4.Power output end VCC is linked into the power input of load circuit, to power to load circuit.The common end grounding of capacitor C E4 and capacitor C E3.
Further, the first end of main output winding N3 i.e. 10 pin is connected with the positive pole of diode D3, and the negative pole of diode D3 is linked among the capacitor C E3.
Further, detect the detection winding circuit that winding N4 connects thereafter setting and also be provided with diode D4, capacitor C 2.Detect the winding out-put supply and after diode D4 rectification, capacitor C 2 filtering, obtain DC power supply, to power to testing circuit.It is between 6 pin and the capacitor C 2 that diode D4 is arranged on the first end that detects winding N4, with the one-way conduction characteristic of passing through diode D4, conducting and the cut-off that control detects winding circuit.
Further, the conducting of the switching tube of switching power source chip U1 or cut-off detect the polarity conversion of winding N4 with control, thus cut-off and the conducting of control diode D4.
Further, the first end that detects winding N4 is connected with the positive pole of diode D4, and the negative pole of diode D4 is linked in the capacitor C 2.
Further, the testing circuit of the present embodiment comprises: the divider resistance R1 that connects successively, and detect resistance R 2.Divider resistance R1 is linked into to detect in the control device with the common port that detects resistance R 2 and changes, calculates.The divider resistance R1 of the present embodiment is parallel to capacitor C 2 two ends after resistance R 2 is connected with detecting.
The detection control device of the present embodiment can be MCU.Preferably, the detection control device of the present embodiment can adopt chip microcontroller.
Further, detection resistance R 2 two ends of the present embodiment are parallel with capacitor C 3.Detect the common end grounding of resistance R 2 and capacitor C 3.
Further, the power sense circuit of the present embodiment is mainly for detection of the civil power of input or the voltage of alternating current.In the present embodiment, input power adopts civil power to describe.
Further, the power sense circuit of the present embodiment also comprises rectification, filter circuit.The rectification circuit of the present embodiment is bridge rectifier.Preferably, adopt full-bridge type rectification circuit DB1 in the present embodiment.Further, the filter circuit of the present embodiment comprises: filter capacitor CE1.
Further, the first input end of the rectification circuit DB1 of the present embodiment, the second input are linked into respectively two outputs that input power is civil power or alternating current.The first end that the first output of rectification circuit DB1 is linked into armature winding N1 is 1 pin.
Another branch road of the first output of rectification circuit DB1 is after the second output of filter capacitor CE1 and rectification circuit DB1 converges, wherein branch road is linked into the source electrode of switching power source chip U1, and the second end that its another branch road is linked into auxiliary winding N2 i.e. 5 pin.The common end grounding of the second end of capacitor C E2 and auxiliary winding N2.
Further, in the present embodiment, in the auxiliary winding circuit, another branch road of the negative pole of diode D2 output is linked into the source S that is linked into switching power source chip U1 after the voltage stabilizing didoe ZD1 that connects successively, the capacitor C 1.The negative pole of voltage stabilizing didoe ZD1 is connected with the negative pole of diode D2.The feedback end FB of the common port access switching power source chip U1 of voltage stabilizing didoe ZD1 and capacitor C 1.
Further, in the present embodiment, in the auxiliary winding circuit, the common port of diode D2 and capacitor C E2 is exported the operating voltage end VDD that another branch road is linked into switching power source chip U1.
Further, auxiliary winding circuit is connected by capacitor C Y1 with the detection winding.It is the common port of 7 pin with the second end that detects winding N4 that capacitor C Y1 one end is linked into capacitor C 2, and the second end that the other end is linked into auxiliary winding is 5 pin.
Further, the drain electrode of switching power source chip U1 i.e. 2 pin of the second end that are linked into armature winding.
Further, the two ends of armature winding N1 are parallel with diode D1 and the transition twin zener dioder TVS1 that connects successively.The first end that the positive pole of transition twin zener dioder TVS1 is linked into armature winding is 1 pin, and the negative pole of transition twin zener dioder TVS1 is connected with the negative pole of diode D1, and the second end of the positive pole access armature winding of diode D1 i.e. 2 pin.
Further, the drain electrode of the switching power source chip U1 i.e. common port of 2 pin and diode D1 of the second end that is linked into armature winding N1.
After the power sense circuit of the present embodiment is connected input power, after namely connecting civil power, through rectification circuit DB1 rectification, after the capacitor C E1 filtering, switching power source chip U1 starts working, armature winding N1 is because of vicissitudinous electric current, and according to the operation principle of transformer, auxiliary winding N2, main output winding N3, detection winding N4 will produce induced electromotive force.Electric current by auxiliary winding N2 passes through diode D2 rectification, reaches capacitor C E2 filtering, flow to the feedback end FB of switching power source chip U1 by voltage stabilizing didoe ZD1, switching power source chip U1 is according to the electric current of the feedback of auxiliary winding N2, inside compares, adjust the conducting duty ratio of switching power source chip U1 internal switch pipe, thereby make secondary winding obtain stable power supply.
Further, when the switching tube conducting of switching power source chip U1 inside, according to transformer Same Name of Ends principle, the voltage relationship of each pin of transformer that can release is: the first end of armature winding N1 namely 1 pin for just, its second end namely 2 pin for bearing; The second end of auxiliary winding N2 namely 5 pin for just, its first end namely 4 pin for bearing; Diode D2 oppositely ends like this, and auxiliary winding circuit will not have outflow of bus current.Equally, the second end of main output winding N3 namely 9 pin for just, its first end namely 10 pin for negative, diode D3 cut-off this moment, the main winding of exporting does not have outflow of bus current.The first end that detects winding N4 namely 6 pin for just, its second end namely 7 pin for negative, diode D4 conducting, row filtering during by capacitor C 2 is given divider resistance R1, is detected resistance R 2 and power.According to the operation principle of transformer as can be known, this moment, the voltage at armature winding N1 two ends was proportional to the voltage that detects winding N4 two ends, and namely the ratio of armature winding N1 and the voltage that detects winding N4 equals the ratio of armature winding N1 and the number of turns that detects winding N4.And the voltage at armature winding N1 two ends is the voltage at capacitor C E1 two ends at this moment, and the voltage at CE1 two ends is proportional to again line voltage.Can release thus, line voltage is proportional to the voltage that detects winding N4 two ends.After detecting winding N4 process diode D4 rectification, capacitor C 2 filtering, then by after divider resistance R1, detection resistance R 2 dividing potential drops, receiving and detecting control device is modulus (A/D) the I/O mouth of single-chip microcomputer, changes by single-chip microcomputer, calculate, can extrapolate current line voltage.
Further, when the cut-off of the switching tube of switching power source chip U1 inside, this moment, upset occured in the positive-negative polarity of armature winding N1, namely this moment armature winding N1 the second end namely 2 pin for just, first end namely 1 pin for bearing.Other several windings i.e. the equally and then upset of positive-negative polarity of auxiliary winding N2, main output winding N3, detection winding N4.Like this, auxiliary winding N2, main output winding N3 be respectively because of the forward conduction of diode D2, diode D3, will carry out charging energy-storing to capacitor C E2, the capacitor C E3 that connects after other, and give corresponding load supplying on auxiliary winding circuit, the main output winding circuit.But detect winding N4 this moment because of diode D4 cut-off, can not be to capacitor C 2 chargings.At this moment, capacitor C 2 can give divider resistance R1, detect resistance R 2 power supplies because of the charging accumulate in last cycle, because the Switching Power Supply switching frequency is high, add that the resistance of divider resistance R1, detection resistance R 2 is very large, capacitor C 2 both end voltage ripples are little, stable, be convenient to single-chip microcomputer and detect.
Because the Switching Power Supply of the present embodiment adopts the high inverse-excitation type switch power-supply of efficient, because the resistance of divider resistance R1, detection resistance R 2 is very large, the power that detection winding N4 consumes is minimum again.When standby, the power consumption of main output winding N3, detection winding N4 is very little again, can realize that like this when standby, power consumption can accomplish to meet the EUP standard of European Union.Simultaneously since for detection of the detection winding N4 on the detection winding circuit of voltage because the power consumption that consumes is extremely low, the energy that consumes like this armature winding N1 is also just very little, and is minimum to the voltage influence at capacitor C E1 two ends, so just can accurately extrapolate line voltage.Through in fact operating circuit test, accuracy is about 1%.
The power sense circuit of the present embodiment, cost is low, makes convenient for production.Because of for detection of the detection winding N4 of line voltage around the number of turns generally seldom, its wire diameter is thin again, required cost is low.Adopt armature winding N1 and auxiliary winding N2 isolation to make, safe and practical.
In the present embodiment, because of the frequency of electric main of input very low, only has 50-60HZ, and the switching frequency of the switching power source chip U1 above frequency that is 50KHZ-100K that is to say, at one of alternating current just in half time-of-week, the on-off times of switching power source chip U1 reaches 1000 times more than the number, at the civil power negative half period, the on-off times of switching power source chip is also more than 1000 times, so can detect in real time equally.
The power sense circuit of the present embodiment, be that the concrete computational process of line voltage is as follows to input power: suppose that line voltage is Vin (AC), the voltage of ordering through A after the rectification circuit DB1 rectification so is that (the K1 value is a definite value to VA=K1 * Vin, can release by correlation formula, here just repeat no more), in the present embodiment, preferred, the K1 value is 1.4.Again according to the operation principle of transformer as can be known: the voltage of establishing armature winding N1 two ends is VN1, the voltage that detects winding N4 two ends is VN4, VN1/VN4=N1/N4(ideally, namely the ratio of the voltage of two windings equals the ratio of the coil turn of two windings), in fact because switching mode power supply transformer TF1 is not desirable part, certain leakage inductance and loss are arranged, top formula is modified to: VN1/VN4=K2 * (N1/N4) (K2 also is a definite value, so can think that two winding voltages and coil turn are proportional).VN1=VA when switching power source chip U1 conducting is so top formula is VA/VN4=K2 * (N1/N4).So the B voltage of ordering be switching mode power supply transformer TF1 detection winding N4 first end namely the voltage V6 of 6 pin deduct again the forward voltage drop (pressure drop to identical diode D4 also is definite value, as is 0.5V) of diode D4.The voltage VB that B is ordered (also being proportional relation) after divider resistance R1, detection resistance R 2 dividing potential drops can obtain C point voltage VC, gives like this I/O mouth of the A/D conversion of single-chip microcomputer.The logical aforementioned proportion relation of keeping can be calculated Vin:Vin=VA/K1=(K2 * N1 * VN4)/(N2 * K1)=(K2 * N1 * (VB+0.5V))/(N2 * K1); And VC=VB * R2/ (R1+R2), namely VB=VC * (R1+R2)/R2 the formula above the VB substitution, just can release the corresponding relation of VB and Vin, thereby can detect line voltage in real time.
Further, can to adjust the voltage that main output winding N3 exports to the power output end VCC of load circuit power supply be the power input of load circuit to the Switching Power Supply of the present embodiment.Increase the weight of such as the load on the load circuit, the frequency of Switching Power Supply or duty ratio can be adjusted automatically.
Further, preferred, because main output winding circuit is opposite with the cut-off and the conducting state that detect winding circuit.It is asynchronous that switching power source chip U1 adjusts the process that process and the switching power source chip U1 control detection winding circuit of the voltage of load input power VCC carry out testing.The power output end VCC that switching power source chip U1 adjusts main output winding circuit is when the switching tube cut-off of switching power source chip U1.It is when the switching tube conducting of switching power source chip U1 that switching power source chip U1 control detection winding circuit is carried out testing, very little energy is provided for detection voltage VC, and two processes are independent of each other basically.
Further, the switching mode power supply transformer TF1 of the present embodiment has leakage inductance and exists, and diode D1 and transition twin zener dioder TVS1 is set is used for absorbing the energy that produces because of leakage inductance, in case switching power source chip U1 damages because reflected voltage is too high.
The above embodiment has only expressed several execution mode of the present invention, and it describes comparatively concrete and detailed, but can not therefore be interpreted as the restriction to claim of the present invention.Should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.Therefore, the protection range of patent of the present invention should be as the criterion with claims.
Claims (10)
1. power sense circuit, it is characterized in that, comprise: Switching Power Supply, and the switching mode power supply transformer that is connected with described Switching Power Supply, described Switching Power Supply comprises: switching power source chip, and described switching power source chip carries out the polarity conversion according to the conducting of internal switch pipe or the winding of cut-off control switch power transformer; Described switching mode power supply transformer comprises: armature winding, auxiliary winding, and secondary winding, described secondary winding comprises: main output winding, detect the detection winding of input power, the first end of described armature winding, the second end of auxiliary winding, the second end of main output winding, the first end that detects winding is Same Name of Ends, the voltage at described armature winding two ends is proportional to described detection winding both end voltage, described auxiliary winding is linked into the feedback end of described switching power source chip, described detection winding is connected with testing circuit, described testing circuit is linked into and detects in the control device input power is carried out voltage detecting, described armature winding and secondary winding isolation.
2. power sense circuit according to claim 1, it is characterized in that: described switching power source chip compares according to the feedback current of described auxiliary winding, adjusts the conducting duty ratio of internal switch pipe so that secondary winding obtains stable power supply; Described switching power source chip is assisted winding or main separately its latter linked auxiliary winding circuit or main cut-off and the conducting of exporting winding circuit or detecting winding circuit of exporting winding or detecting winding according to conducting or the cut-off control of internal switch pipe.
3. power sense circuit according to claim 1 is characterized in that: the operating state of switching tube of described switching power source chip of controlling the conducting of described detection winding circuit or disconnection is opposite with the described auxiliary winding circuit of control; Described Switching Power Supply basis is adjusted frequency or the duty ratio of this Switching Power Supply automatically by the loading condition of the load circuit of the power output end connection of described main output winding, to adjust the main output voltage of exporting the power output end of winding.
4. power sense circuit according to claim 1, it is characterized in that: described auxiliary winding connects thereafter auxiliary winding circuit and is provided with diode D2, capacitor C E2, described auxiliary winding output through diode D2 rectification, and capacitor C E2 filtering after obtain DC power supply, and power supply is to switching power source chip; Described diode D2 is arranged between the first end and described capacitor C E2 of described auxiliary winding, to pass through diode D2 with cut-off and the conducting of control connection in described auxiliary winding auxiliary winding circuit thereafter; The main output winding circuit that described main output winding connects thereafter setting is provided with diode D3, capacitor C E3, and the output of described main output winding is through diode D3 rectification, and capacitor C E3 filtering; Described diode D3 is arranged between the first end and described capacitor C E3 of described main output winding, to be arranged at conducting and the cut-off of described main output winding main output winding circuit thereafter by diode D3 control connection; The detection winding circuit that described detection winding connects thereafter setting is provided with diode D4, capacitor C 2, and described detection winding output obtains DC power supply to power to testing circuit after diode D4 rectification, capacitor C 2 filtering; Described diode D4 is arranged between the first end and described capacitor C 2 of described detection winding, to be arranged on conducting and the cut-off of described detection winding detection winding circuit thereafter with control connection by diode D4.
5. power sense circuit according to claim 4, it is characterized in that: described capacitor C E3 two ends are parallel with LC circuit, described LC circuit comprises: the inductance L 1, the capacitor C E4 that connect successively, described main output winding out-put supply through behind diode D3, the capacitor C E3 rectifying and wave-filtering, again through inductance L 1 filtering, and capacitor C E4 again after the filtering output DC source power the common end grounding of described capacitor C E4 and capacitor C E3 to load circuit; The first end of described auxiliary winding accesses the positive pole of described diode D2, and the first end of described main output winding is connected with the positive pole of described diode D3, and the first end of described detection winding is connected with the positive pole of described diode D4.
6. according to claim 4 or 5 described power sense circuits, it is characterized in that: described testing circuit comprises: interconnective divider resistance R1, and detect resistance R 2, described divider resistance R1 is linked into to detect in the control device with the common port that detects resistance R 2 and changes, calculates; Described detection resistance R 2 two ends are parallel with capacitor C 3, detect the common end grounding of resistance R 2 and capacitor C 3; After described divider resistance R1 connects with described detection resistance R 2 and described capacitor C 2 in parallel; Described main output winding, detect winding and be winding independently.
7. according to claim 4 or 5 described power sense circuits, it is characterized in that: the source electrode that is linked into described switching power source chip after the voltage stabilizing didoe ZD1 that another branch road access of the negative pole output of described diode D2 connects successively, the capacitor C 1, the negative pole of described voltage stabilizing didoe ZD1 is connected with the negative pole of described diode D2, and the common port of described voltage stabilizing didoe ZD1 and capacitor C 1 accesses the feedback end of described switching power source chip.
8. according to claim 4 or 5 described power sense circuits, it is characterized in that: the common port of described diode D2 and capacitor C E2 is exported the operating voltage end that another branch road is linked into described switching power source chip, and the drain electrode of described switching power source chip is linked into the second end of described armature winding; Described capacitor C 2 is linked into second end of assisting winding with the common port that detects winding by capacitor C Y1 is set.
9. according to claim 1 to the described power sense circuit of 5 any one, it is characterized in that: also comprise rectification, filter circuit, described filter circuit comprises: filter capacitor CE1, the first input end of described rectification circuit, the second input are linked into respectively two outputs of input power, and the first output of described rectification circuit is linked into the first end of described armature winding; Another branch road of the first output of described rectification circuit is after the second output of filter capacitor CE1 and described rectification circuit converges, and wherein a branch road is linked into the source electrode of described switching power source chip, the second end that its another branch road is linked into described auxiliary winding; The common end grounding of the second end of described capacitor C E2 and described auxiliary winding.
10. according to claim 1 to the described power sense circuit of 5 any one, it is characterized in that: the two ends of described armature winding are parallel with diode D1 and the transition twin zener dioder TVS1 that connects successively, the positive pole of described transition twin zener dioder TVS1 is linked into the first end of described armature winding, and the negative pole of described transition twin zener dioder TVS1 is connected and accesses by positive pole the second end of described armature winding with the negative pole of described diode D1.
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| CN2012104812292A CN102957324A (en) | 2012-11-23 | 2012-11-23 | Power detection circuit |
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| CN2012104812292A CN102957324A (en) | 2012-11-23 | 2012-11-23 | Power detection circuit |
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| CN113612395A (en) * | 2021-09-06 | 2021-11-05 | 深圳市优优绿能电气有限公司 | Auxiliary power supply circuit with ultralow standby power consumption |
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Application publication date: 20130306 |