CN208720450U - A kind of guard time adjusts circuit, PFC current foldback circuit and controller - Google Patents
A kind of guard time adjusts circuit, PFC current foldback circuit and controller Download PDFInfo
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- CN208720450U CN208720450U CN201821337899.6U CN201821337899U CN208720450U CN 208720450 U CN208720450 U CN 208720450U CN 201821337899 U CN201821337899 U CN 201821337899U CN 208720450 U CN208720450 U CN 208720450U
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Abstract
The utility model discloses a kind of guard times to adjust circuit, PFC current foldback circuit and controller; the first end that the guard time adjusts the first resistor in circuit adjusts the input terminal of circuit as guard time; it is connected with protection signal output unit, the second end of first resistor is connected with the common end of second resistance, first capacitor；The other end of second resistance is connected with power end VCC, and another termination of first capacitor is with reference to ground；After first controllable switch and 3rd resistor series connection; it is connected to power end VCC and with reference between ground; the control terminal of first controllable switch is connected with the second end of first resistor, and the common end of the first controllable switch and 3rd resistor is the output end that guard time adjusts circuit, is connected with protection execution unit.Circuit adjustable triggered time and triggering retention time are adjusted by the guard time, so that circuit is responded rapidly to protection signal, and after protecting blackout, delay protection.
Description
Technical field
The utility model relates to circuit protection technical field, more specifically, it relates to a kind of guard time adjust circuit,
PFC current foldback circuit and controller.
Background technique
Standing to be equipped with protection circuit for electrical apparatus control equipment, protection circuit executes protection act according to protection signal, no
Requirement of the same control equipment or usage scenario to guard time is different.When guard time includes triggered time and triggering holding
Between；Triggered time is that protection circuit receives protection signal to the time for executing protection act；The triggering retention time is to protect
After blackout, protection circuit still carries out the duration of protection act.
Utility model content
In view of this, the present invention provides a kind of guard times to adjust circuit, PFC current foldback circuit and control
Device can be realized the adjusting of guard time.
To achieve the above object, the utility model provides the following technical solutions:
A kind of guard time adjusting circuit, comprising: first resistor, second resistance, 3rd resistor, first capacitor and first can
Control switch, in which:
The first end of the first resistor adjusts the input terminal of circuit as guard time, with protection signal output unit phase
Even, the second end of the first resistor is connected with the common end of the second resistance, the first capacitor；The second resistance
The other end is connected with power end VCC, and another termination of the first capacitor is with reference to ground；
After first controllable switch and 3rd resistor series connection, it is connected between the power end VCC and the reference ground,
The control terminal of first controllable switch is connected with the second end of the first resistor, first controllable switch and the third
The common end of resistance is the output end that the guard time adjusts circuit, is connected with protection execution unit.
A kind of PFC current foldback circuit, comprising: sampling unit, protection signal output unit, protection execution unit and protection
Time adjustment unit, it includes that above-mentioned guard time adjusts circuit, the input of the sampling unit that the guard time, which adjusts unit,
End is connected with the main operating circuit of PFC, and the output end of the sampling unit is connected with the input terminal of the protection signal output unit；
The input terminal that the guard time adjusts circuit is connected with the output end of the protection signal output unit, the guard time tune
The output end on economize on electricity road is connected with the input terminal of the protection execution unit, and the output end of the protection execution unit exports control
Signal, the control signal control the main operating circuit electric current of the PFC and reduce.
A kind of controller, for controlling air-conditioning, comprising: above-mentioned PFC current foldback circuit.
A kind of guard time disclosed in the utility model embodiment adjusts circuit, PFC current foldback circuit and controller, should
It includes: first resistor, second resistance, 3rd resistor, first capacitor and the first controllable switch, the first electricity that guard time, which adjusts circuit,
The first end of resistance adjusts the input terminal of circuit as guard time, is connected with protection signal output unit, and the second of first resistor
End is connected with the common end of second resistance, first capacitor；The other end of second resistance is connected with power end VCC, first capacitor
Another termination is with reference to ground；After first controllable switch and 3rd resistor series connection, it is connected between power end VCC and reference ground, first
The control terminal of controllable switch is connected with the second end of first resistor, when the common end of the first controllable switch and 3rd resistor is protection
Between adjust circuit output end, with protection execution unit be connected.The circuit adjustable triggered time is adjusted by the guard time
And the triggering retention time, so that circuit is responded rapidly to protection signal, and after protecting blackout, delay protection.
Detailed description of the invention
In order to illustrate the embodiment of the utility model or the technical proposal in the existing technology more clearly, below will be to embodiment
Or attached drawing needed to be used in the description of the prior art is briefly described, it should be apparent that, the accompanying drawings in the following description is only
It is the embodiments of the present invention, for those of ordinary skill in the art, without creative efforts, also
Other attached drawings can be obtained according to the attached drawing of offer.
Fig. 1 is that a kind of guard time provided by the embodiment of the utility model adjusts electrical block diagram；
Fig. 2 is that another guard time provided by the embodiment of the utility model adjusts electrical block diagram；
Fig. 3 is that another guard time provided by the embodiment of the utility model adjusts electrical block diagram；
Fig. 4 is a kind of PFC current foldback circuit structural block diagram provided by the embodiment of the utility model；
Fig. 5 is another kind PFC current foldback circuit structural block diagram provided by the embodiment of the utility model；
Fig. 6 is PFC current foldback circuit structural schematic diagram provided by the embodiment of the utility model.
Specific embodiment
The following will be combined with the drawings in the embodiments of the present invention, carries out the technical scheme in the embodiment of the utility model
Clearly and completely describe, it is clear that the described embodiments are only a part of the embodiments of the utility model, rather than whole
Embodiment.Based on the embodiments of the present invention, those of ordinary skill in the art are without making creative work
Every other embodiment obtained, fall within the protection scope of the utility model.
As shown in Figure 1, the utility model embodiment provides a kind of guard time adjusting circuit, specifically, when the protection
Between to adjust circuit include: first resistor R1, second resistance R2,3rd resistor R3, first capacitor C1 and the first controllable switch K1,
In:
As shown in Figure 1, the first end of above-mentioned first resistor R1 adjusts the input terminal of circuit as guard time, believe with protection
Number output unit is connected, the common end of the second end of above-mentioned first resistor R1 and above-mentioned second resistance R2, above-mentioned first capacitor C1
It is connected；The other end of above-mentioned second resistance R2 is connected with power end VCC, and another termination of above-mentioned first capacitor C1 is with reference to ground
GND；The first end of above-mentioned first controllable switch K1 is connected with above-mentioned power end VCC, the second end of above-mentioned first controllable switch K1
It is connected with the first end of above-mentioned 3rd resistor R3, the control terminal of above-mentioned first controllable switch K1 and the second of above-mentioned first resistor R1
End is connected, and the second termination of above-mentioned 3rd resistor R3 is with reference to ground；The second end of above-mentioned first controllable switch K1 and above-mentioned third electricity
The common end for hindering the first end of R3 adjusts the output end of circuit as above-mentioned guard time, is connected with protection execution unit.
As shown in Fig. 2, the utility model embodiment additionally provides a kind of guard time adjusting circuit, which is adjusted
Circuit includes: first resistor R1, second resistance R2,3rd resistor R3, first capacitor C1 and the first controllable switch K1, in which: the
The first end of one resistance R1 adjusts the input terminal of circuit as guard time, is connected with protection signal output unit, and above-mentioned first
The second end of resistance R1 is connected with the common end of above-mentioned second resistance R2, above-mentioned first capacitor C1；Above-mentioned second resistance R2's is another
One end is connected with power end VCC, and the other end of above-mentioned first capacitor C1 connects with reference to ground GND；The of above-mentioned 3rd resistor R3
One end is connect with power end VCC, and the other end of above-mentioned 3rd resistor R3 is connect with the first end of the first controllable switch K1, and first
The control terminal of controllable switch K1 is connected with the second end of above-mentioned first resistor R1, the second end connection of above-mentioned first controllable switch K1
To reference GND.The common end of above-mentioned first controllable switch K1 and above-mentioned 3rd resistor R3 adjusts electricity as above-mentioned guard time
The output end on road is connected with protection execution unit.The output state of above-mentioned protection signal output unit includes high-impedance state and low group
State adjusts the triggered time by the capacitance of the resistance value and above-mentioned first capacitor that adjust above-mentioned first resistor, above-mentioned by adjusting
The capacitance of the resistance value of second resistance and above-mentioned first capacitor adjusts the triggering retention time.
It should be noted that guard time is divided into triggered time and triggering retention time in the utility model embodiment,
In:
Triggered time is that input terminal reception protects signal output unit output protection signal to execute guarantor to protection execution unit
The time of shield movement.Triggering the retention time is after abnormal conditions disappear, and the protection signal of protection signal output unit output disappears
After losing (such as high-impedance state when being changed into normal work by low resistance state), protection execution unit, which remains unchanged, executes continuing for protection act
Time.
In the following, being illustrated in conjunction with a specific embodiment to the working principle of the circuit, as shown in Fig. 1, it is assumed that the
One controllable switch K1 is NPN type triode, it is assumed that low-resistance is presented in protection signal output unit when being abnormal (such as overcurrent)
State state, and execution unit is protected to execute guarantor when receiving the low level control signal of guard time adjusting circuit output
(such as main switch of the pfc circuit) electric current of shield movement, i.e. control governor circuit reduces.In the present embodiment, when being abnormal
When, to realize protection, guard time adjusts circuit and needs to export low level signal, then the control electrode base stage of the NPN type triode
Voltage should be low level.When an anomaly occurs, protecting the output impedance of signal output unit becomes low resistance state from high-impedance state, this
When, because the upper voltage of first capacitor C1 cannot be mutated, first capacitor C1 believes by the output of resistance R1 and presentation low resistance state
Number protection location discharges, after the low level voltage needed for the voltage on first capacitor C1 is discharged into NPN type triode base stage,
NPN type triode shutdown, emitting stage export low level, which exports to protection execution unit.Therefore, this implementation
In example, the triggered time can be adjusted by adjusting the resistance value of first capacitor C1 and first resistor R1.Similarly, after abnormal disappearance,
High-impedance state is become from low resistance state although protecting the output impedance of signal output unit, the same voltage because of first capacitor C1 is not
It can be mutated, therefore the base stage of NPN type triode cannot become high level at once, and needs delay a period of time, delay time are
VCC charges to first capacitor C1 by second resistance R2, so that the voltage on first capacitor C1 reaches NPN type triode base
The time of extremely required high level voltage, therefore, in the present embodiment, by adjusting the value of second resistance R2 and first capacitor C1,
The adjustable triggering retention time.In the present embodiment, other conditions are constant, it is assumed that protection execution unit is receiving guard time
When adjusting the control signal of the high level of circuit output, protection act is executed, at this point, by adjusting the electricity of second resistance R2 and first
Hold the value of C1, adjustable triggered time, by the adjustable triggering of value for adjusting first resistor R1 and first capacitor C1
Retention time.Therefore, the utility model is realized by the adjustment to first resistor R1, second resistance R2 and first capacitor C1 value
The adjusting of guard time.
It should be noted that above-described embodiment is only to illustrate circuit theory, the restriction to the utility model should not be construed as,
First controllable switch can also be other controllable switches in addition to above-mentioned NPN type triode, and guard time adjusts circuit can basis
Specific relay protective scheme is realized using above-mentioned principle and circuit topology provided by the embodiment of the utility model.In addition, high-impedance state table
Show that there are some node in circuit other in opposing circuit to put relatively higher impedance；When protection signal output unit is in high resistant
When state, guard time, which adjusts unit, can not inject electric signal protection signal output unit；On the contrary, when protection signal output unit
When in low resistance state, protection signal conditioning unit can be injected electric signal with reference to ground by protection signal output unit, that is, first
Capacitor C1 can pass through the lesser first capacitor R1 of resistance value and protection signal output unit electric discharge.
As shown in figure 3, it can also include: the 4th resistance R4 that the guard time, which adjusts circuit, above-mentioned on the basis of Fig. 1
One end of 4th resistance R4 is connected with the second end of above-mentioned first resistor R1, the other end and above-mentioned first of above-mentioned 4th resistance R4
The control terminal of controllable switch K1 is connected.The 4th resistance R4 is arranged between first resistor R1 and the first controllable switch K1 can be into
One step expands the adjustable range of guard time, adjusts the charging of first capacitor C1 jointly by second resistance R2 and the 4th resistance R4
Time.
In the above-described embodiments, above-mentioned first controllable switch K1 is triode, metal-oxide-semiconductor or IGBT.
Guard time provided by the embodiment of the utility model adjusts circuit and passes through first resistor R1, second resistance R2 and the
One capacitor C1 realizes the adjusting of guard time, when an exception occurs, its quick response is made to protect signal；When protection blackout
When, it realizes delay process, realizes the stability of protection, on the other hand, moreover it is possible to avoid short time interior generation repeatedly abnormal, lead to frequency
Numerous execution protection act, damage device.
Guard time provided by the embodiment of the utility model adjusts circuit and can be used in a variety of circuit protections, for example overcurrent is protected
Shield, overvoltage protection；For different use occasions, it is only necessary to which protection signal output unit and protection in the protection circuit executes
Above-mentioned guard time is added between unit and adjusts circuit, to realize the adjusting of guard time.Wherein, signal output unit is protected
Output protection signal, protection execution unit execute protection act according to protection signal.It illustrates, it is assumed that protection signal is low electricity
It is flat, then protect signal output unit to judge whether to be abnormal (over-voltage or mistake according to the detection or sampled result in tested circuit
Situations such as stream), in case of exception, then protect signal output unit to export low level to execution unit is protected, protection executes list
After member receives low level protection signal, protection act is executed, the parametric regression for controlling tested circuit is normal.
Circuit is adjusted based on above-mentioned guard time, the utility model embodiment also discloses a kind of PFC current foldback circuit,
As shown in Figure 4, comprising: sampling unit 2, protection signal output unit 3, protection execution unit 4 and guard time adjust unit 5,
It includes that any one guard time described in above-described embodiment adjusts circuit, above-mentioned sampling list that the guard time, which adjusts unit 5,
The electric current that the input terminal of member 2 is connected with the main operating circuit 1 of PFC, samples the main operating circuit of PFC obtains sample rate current, above-mentioned sampling
The output end of unit 2 is connected with the input terminal of above-mentioned protection signal output unit 3；Above-mentioned guard time adjusts the input of unit 5
End is connected with the output end of above-mentioned protection signal output unit 3, the output end of above-mentioned guard time adjusting unit 5 and above-mentioned protection
The input terminal of execution unit 4 is connected, and the output end output control signal of above-mentioned protection execution unit, the control signal controls institute
The main operating circuit electric current of PFC is stated to reduce.Specifically, above-mentioned control signal can be exported to the main switch of the main operating circuit of PFC
The control terminal of pipe reduces to control above-mentioned electric current.
In the present embodiment, the main operating circuit of PFC can be boost (boosting) circuit, and buck (decompression) circuit etc. is right
This is not construed as limiting.Main switch can be the controllable switches such as IGBT, metal-oxide-semiconductor or triode.
As shown in figure 5, a kind of PFC current foldback circuit provided by the embodiment of the utility model, on the basis of above-mentioned Fig. 4
On, further includes: sampled signal amplifying unit 6, the input terminal of above-mentioned sampled signal amplifying unit 6 are connected to above-mentioned sampling unit 2,
Sampled signal is amplified.The output end of above-mentioned sampled signal amplifying unit 6 is defeated with above-mentioned protection signal output unit 3
Enter end to be connected, above-mentioned sampling unit 2 includes sampling resistor RS1.
Below with reference to a specific embodiment, as shown in fig. 6, in the present embodiment, guard time adjusts circuit and is used in
In the protection of the main operating circuit 1 of PFC, concrete principle is as follows:
In the present embodiment the main operating circuit 1 of PFC be boost booster circuit, comprising: inductance L1, IGBT module G1 and quickly
Recovery diode D1, specific connection structure are shown in Figure 6.
Above-mentioned sampled signal amplifying unit 6 includes: the 5th resistance R5, the 6th resistance R6, the 7th resistance R7, the 8th resistance
R8 and operational amplifier IC1A, in which: the inverting input terminal (-) of above-mentioned operational amplifier IC1A and above-mentioned operational amplifier
The output end of IC1A is connected by above-mentioned 5th resistance R5；The positive input (+) of above-mentioned operational amplifier IC1A passes through above-mentioned
6th resistance R6 is connected with one end of above-mentioned sampling resistor RS1, and the reverse input end (-) of above-mentioned operational amplifier IC1A passes through upper
It states the 7th resistance R7 to be connected with the other end of above-mentioned sampling resistor RS1, the output end of above-mentioned operational amplifier IC1A is as above-mentioned
The output end of sampled signal amplifying unit 6 is connected with the input terminal of above-mentioned protection signal output unit.
Above-mentioned protection signal output unit 3 includes: the 9th resistance R9, the tenth resistance R10, eleventh resistor R11 and ratio
Compared with device U1A, in which: the sampling end of above-mentioned comparator U1A is put by one end of above-mentioned eleventh resistor R11 with above-mentioned sampled signal
The output end of big unit 6 is connected, and receives the output signal of above-mentioned sampled signal amplifying unit 6；The reference edge of above-mentioned comparator U1A
It is connected by above-mentioned 9th resistance R9 with above-mentioned power end VCC, and is connect by above-mentioned tenth resistance R10 with reference to ground；Above-mentioned comparison
The output end of device U1A adjusts the input of unit 5 as the output end of above-mentioned protection signal output unit 3 and above-mentioned guard time
End is connected；According to the size of the output signal of said reference signal and above-mentioned sampled signal amplifying unit, above-mentioned comparator is presented
High-impedance state or low resistance state.
It should be noted that the reference edge of above-mentioned comparator U1A is in the utility model embodiment by adjusting above-mentioned
The sampling end acquisition sampling of the resistance value of nine resistance R9 and above-mentioned tenth resistance R10 setting protection threshold value, above-mentioned comparator U1A is put
The amplified signal of acquisition is compared processing with threshold value by the big amplified signal of circuit 2, above-mentioned comparator U1A, when reaching
To when protecting threshold value, the output end of above-mentioned comparator U1A exports low level, and comparator U1A is in low resistance state.
Above-mentioned protection execution unit 4 includes: twelfth resistor R12, thirteenth resistor R13 and the second controllable switch K2,
In: one end of above-mentioned twelfth resistor R12 adjusts unit as the input terminal of above-mentioned protection execution unit 4 and above-mentioned guard time
5 output end is connected, and receives above-mentioned guard time and adjusts the control signal that unit 5 exports；Above-mentioned twelfth resistor R12's is another
One end is connected with the control terminal of above-mentioned second controllable switch K2, and is connected with the first end of above-mentioned thirteenth resistor R13, and above-mentioned
The second termination of 13 resistance R13 is with reference to ground；With reference to ground, above-mentioned second controllably opens the second termination of above-mentioned second controllable switch K2
The first end for closing K2 is connected to the main switch of above-mentioned PFC main circuit 1 as the output end of above-mentioned protection execution unit 4.
As shown in fig. 6, above-mentioned second controllable switch K2 is triode, metal-oxide-semiconductor or IGBT, specifically, above-mentioned first is controllable
Switch K1 is PNP triode Q1, and above-mentioned second controllable switch K2 is NPN triode Q2, as 3rd resistor R3 and the common end Q1
When voltage is VCC, IGBT driving end is pulled low, then IGBT drives end to be forced to turn off, and is not controlled by software-driven, as PNP tri-
Pole pipe Q1 works in off state, and 3rd resistor R3 and the common end Q1 voltage are 0V, and NPN triode Q2 works in cut-off region,
IGBT drive end be high-impedance state, IGBT driving can be under software control at this time, the main operating circuit of PFC software control effect under just
Often work.
Before trigger protection, comparator U1A output is high-impedance state, and PNP triode Q1 work at this time is in cut-off region, power supply
End VCC voltage concentrates on first capacitor C1；After trigger protection, comparator U1A output is low level in several microseconds, is led to
Crossing setting first resistor R1 resistance value is low resistance, and the charge quick release on first capacitor C1 is fallen so that PNP triode Q1 is saturated
It is connected, pressure drop is concentrated on substantially on 3rd resistor R3 on power end VCC, and 3rd resistor R3 exports high level, so that IGBT drives
Signal-off；Electric current drops to threshold value hereinafter, comparator U1A output restores high-impedance state after hardware protection.Not due to capacitance voltage
The reason of capable of being mutated, the voltage on first capacitor C1 is essentially 0V at this time, and PNP triode Q1 maintains the saturation state of front, leads to
The resistance for crossing setting second resistance R2 and the 4th resistance R4 is larger resistance value, can slowly be charged to first capacitor C1, until first
Capacitor C1 voltage reaches PNP triode Q1 turn-off criterion, and the time of this process can pass through the capacitor of adjusting first capacitor C1
Value and the resistance value of second resistance R2 and the 4th resistance R4 control.
The utility model embodiment offer is added to guard time on the basis of original and adjusts unit, is opened using comparator
The high resistant step response dragged down under characteristic and turn-off characteristic under logical state, so that the electric discharge and charging of first capacitor C1 do not exist
On one circuit, triggered time and triggering retention time can be respectively designed, realizes and adjusts triggered time and triggering retention time,
Avoid multiple Damage by Short Circuit IGBT module in the short time.
Generally, the guard time that current protecting circuit requires all is several microseconds, so when design hardware protection circuit, fortune
Calculating amplifier and comparator all needs selection to react cracking component.Electric current can trigger hardware protection and software when reaching protection value
Protection turns off IGBT driving signal；In practice, can by hardware, also can by software switching-off IGBT driving signal, from
And realize protection.But because software, which receives protection signal, turns off driving signal time much longer than hardware to issuing, work as hardware
Software protection triggers not yet when protection has been switched off driving signal, and software does not stop the offer of driving signal at this time.Work as electricity
When flow valuve is reduced to that hardware protection releases after threshold value or less, there is also IGBT can secondary conducting even repetition for software driving signal
Time conducting is connected or more in the above reason three times, and repeatedly conducting is possible to damage IGBT module.By provided by the utility model
Guard time delay circuit can avoid such case.
The utility model embodiment additionally provides a kind of controller, and for controlling air-conditioning, which includes: above-mentioned implementation
The PFC current foldback circuit that example provides.
It should be noted that all the embodiments in this specification are described in a progressive manner, each embodiment weight
Point explanation is the difference from other embodiments, and the same or similar parts between the embodiments can be referred to each other.
It is exemplarily described above in conjunction with the circuit that attached drawing proposes the utility model, the explanation of above embodiments
It is merely used to help understand the core concept of the utility model.For those of ordinary skill in the art, according to the utility model
Thought, there will be changes in the specific implementation manner and application range.In conclusion the content of the present specification should not be understood
For limitations of the present invention.
The foregoing description of the disclosed embodiments can be realized professional and technical personnel in the field or using originally practical new
Type.Various modifications to these embodiments will be readily apparent to those skilled in the art, and determine herein
The General Principle of justice can be realized in other embodiments without departing from the spirit or scope of the present utility model.Cause
This, the present invention will not be limited to the embodiments shown herein, and is to fit to and principles disclosed herein
The widest scope consistent with features of novelty.
Claims (10)
1. a kind of guard time adjusts circuit characterized by comprising first resistor, second resistance, 3rd resistor, the first electricity
Hold and the first controllable switch, in which:
The first end of the first resistor adjusts the input terminal of circuit as guard time, is connected with protection signal output unit,
The second end of the first resistor is connected with the common end of the second resistance, the first capacitor；The second resistance it is another
One end is connected with power end VCC, and another termination of the first capacitor is with reference to ground；
After first controllable switch and 3rd resistor series connection, it is connected between the power end VCC and the reference ground, it is described
The control terminal of first controllable switch is connected with the second end of the first resistor, first controllable switch and the 3rd resistor
Common end be the guard time adjust circuit output end, with protection execution unit be connected.
2. guard time according to claim 1 adjusts circuit, which is characterized in that described to protect the defeated of signal output unit
It does well including high-impedance state and low resistance state, by adjusting the resistance value of the first resistor, the resistance value of the second resistance and described
The capacitance of first capacitor adjusts triggered time or triggering retention time.
3. guard time according to claim 2 adjusts circuit, which is characterized in that further include: the 4th resistance, the described 4th
One end of resistance is connected with the second end of the first resistor, the other end and first controllable switch of the 4th resistance
Control terminal is connected.
4. guard time according to claim 1-3 adjusts circuit, which is characterized in that first controllable switch
For triode, metal-oxide-semiconductor or IGBT.
5. a kind of PFC current foldback circuit characterized by comprising sampling unit, protection signal output unit, protection execute
Unit and guard time adjust unit, and it includes described in 1 to 4 any one of the claims that the guard time, which adjusts unit,
Guard time adjusts circuit, and the input terminal of the sampling unit is connected with the main operating circuit of PFC, the output end of the sampling unit
It is connected with the input terminal of the protection signal output unit；The guard time adjusts the input terminal and the protection signal of circuit
The output end of output unit is connected, and the guard time adjusts the input terminal phase of the output end and the protection execution unit of circuit
Even, the output end output control signal of the protection execution unit, the control signal control the main operating circuit electric current of PFC
Reduce.
6. PFC current foldback circuit according to claim 5, which is characterized in that further include: sampled signal amplifying unit,
The input terminal of the sampled signal amplifying unit is connected with the sampling unit, the output end of the sampled signal amplifying unit with
The input terminal of the protection signal output unit is connected, and the sampling unit includes sampling resistor, and the sampled signal amplification is single
Member includes: the 5th resistance, the 6th resistance, the 7th resistance, the 8th resistance and operational amplifier, in which:
The inverting input terminal of the operational amplifier is connected with the output end of the operational amplifier by the 5th resistance；
The positive input of the operational amplifier is connected by the 6th resistance with one end of the sampling resistor, the fortune
The reverse input end for calculating amplifier is connected by the 7th resistance with the other end of the sampling resistor, the operational amplifier
Output end as the sampled signal amplifying unit output end with it is described protection signal output unit input terminal be connected.
7. PFC current foldback circuit according to claim 6, which is characterized in that the protection signal output unit includes:
9th resistance, the tenth resistance, eleventh resistor and comparator, in which:
The sampling end of the comparator passes through one end of the eleventh resistor and the output end of the sampled signal amplifying unit
It is connected, receives the output signal of the sampled signal amplifying unit；
The reference edge of the comparator is connected by the 9th resistance with the power end VCC, and passes through the tenth resistance
It connects with reference to ground；
The output end of the comparator adjusts unit as the output end of the protection signal output unit and the guard time
Input terminal be connected；
According to the size of reference signal and the output signal of the sampled signal amplifying unit, the comparator present high-impedance state or
Person's low resistance state.
8. PFC current foldback circuit according to claim 7, which is characterized in that the protection execution unit includes: the tenth
Two resistance, thirteenth resistor and the second controllable switch, in which:
One end of the twelfth resistor adjusts unit as the input terminal of the protection execution unit and the guard time
Output end is connected, and receives the control signal that the guard time adjusts unit output；
The other end of the twelfth resistor is connected with the control terminal of second controllable switch, and with the thirteenth resistor
First end is connected, and the second termination of the thirteenth resistor is with reference to ground；
With reference to ground, the first end of second controllable switch executes second termination of second controllable switch as the protection
The output end of unit is connected to the main switch of the PFC main circuit.
9. PFC current foldback circuit according to claim 8, which is characterized in that second controllable switch be triode,
Metal-oxide-semiconductor or IGBT.
10. a kind of controller, for controlling air-conditioning characterized by comprising described in the claims 5-9 any one
PFC current foldback circuit.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821337899.6U CN208720450U (en) | 2018-08-16 | 2018-08-16 | A kind of guard time adjusts circuit, PFC current foldback circuit and controller |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821337899.6U CN208720450U (en) | 2018-08-16 | 2018-08-16 | A kind of guard time adjusts circuit, PFC current foldback circuit and controller |
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| CN208720450U true CN208720450U (en) | 2019-04-09 |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108731213A (en) * | 2018-08-16 | 2018-11-02 | 珠海恒途电子有限公司 | A kind of guard time adjusts circuit, PFC current foldback circuits and controller |
-
2018
- 2018-08-16 CN CN201821337899.6U patent/CN208720450U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108731213A (en) * | 2018-08-16 | 2018-11-02 | 珠海恒途电子有限公司 | A kind of guard time adjusts circuit, PFC current foldback circuits and controller |
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