Bjt saturation. BJT. MOSFET. BJT is PNP or NPN: MOSFET is N-type or P-type: BJ...

How to identify the Saturation in BJT? What is Hard Saturatio…

The transistor can be operated in three modes: Cut-off mode. Saturation mode. Active mode. In order to operate transistor in one of these regions, we have to supply dc voltage to the npn or pnp transistor. Based on the polarity of the applied dc voltage , the transistor operates in any one of these regions.In this video, how the transistor (BJT) acts as a switch is explained with an example. Along with that, it is also explained, how to identify the saturation ...When the transistor goes into saturation it attain the maximum Collector current possible in a given circuit (static DC situation. When coils and capacitors are involved its another story) . If you keep pushing some current into the base by raising Vb you will inevitably keep staying in saturation status but absolute Vb and absolute Ve will ...Popular answers (1) Amit Das. Jawaharlal Nehru University. Reverse saturation current terminology is generally used in diode whereas leakage current is used in BJT. But both are more or less ...Jan 11, 2023 · Definition of saturation: A collector current that produces a collector voltage Vc which is smaller than the base voltage Vb (npn case). That means: Because of Vbc>0 the base-collector junction now is forward biased (in contrast to the "normal" operation) and the base current Ib now consists of two parts (through the emitter and through the collector node). Figure 3: In Saturation, Collector and Emitter are Nearly Shorted Together Using the two states of cutoff and saturation, the transistor may be used as a switch. The collector and emitter form the switch terminals and the base is the switch handle. In other words, the small1. BJT: Regions of Operation • Forward active: device has high voltage gain and high β; • Reverse active: poor β; not useful; • Cut-off: negligible current: nearly an open circuit; • Saturation: device is flooded with minority carriers; – ⇒takes time to get out of saturation saturation cut-off reverse forward active VBC VBC VCE ... A bipolar junction transistor, BJT, is a single piece of silicon with two back-to-back P-N junctions.BJTs can be made either as PNP or as NPN. Figure 1: Structures, layers and circuit symbol of NPN transistor. They have three regions and three terminals, emitter, base, and collector represented by E, B, and C respectively.In using a transistor to operate as a switch you must drive it into saturation. Saturation happens when the collector current cannot further increase despite there is base current increase. The saturation level of every transistor varies. The usual range is from 0.7V to ideally zero. For.BJTs PNP and NPN schematic symbols. 3D model of a TO-92 package, commonly used for small bipolar transistors. A bipolar junction transistor ( BJT) is a type of transistor that uses both electrons and electron holes as charge carriers. In contrast, a unipolar transistor, such as a field-effect transistor (FET), uses only one kind of charge carrier.3 Answers. Sorted by: 1. In a BJT, Forward active mode is when Emitter Base Junction (EBJ) is forward biased and the Collector based junction (CBJ) is reverese biased. …History of Bipolar Junction Transistors. The transistor (BJT) was not the first three terminal devices. Before transistors came into existence vacuum tubes were used. In electronics, vacuum tube triodes were used almost for half a century before the BJT’s.The light bulb invented by Thomas Edison in the early 1880’s was one of the first uses of vacuum tubes for any …They are compact, lightweight and powerful enough to drive small machines accurately. They are suitable for working with lighter materials, such as plastics, thin wood and PCBs. NEMA 14: These motors are smaller than NEMA 17 and are ideal for ultra-compact CNC machines or applications where space is limited.Explanation: To obtain an approximate answer, under saturation the BJT is ON and hence acts as a short circuit. However, ideally a drop exists for the transistor which is a fixed value. For an exact answer, if the BJT is a Silicon transistor, then drop V CE = 0.2V and current is 20-0.2/2.2=9.9 mA.A Bipolar Junction Transistor (BJT) is a current-controlled semiconductor device which has three-terminals. The current in BJT is carried by both majority and minority carriers so it is known as bipolar device. The input resistance of BJT is low so it is used as an amplifier, oscillator circuits and digital circuits. Contents show.The BJT is a three terminal device and it comes in two different types. The npn BJT and the pnp BJT. The BJT symbols and their corresponding block diagrams are shown on Figure 1. The BJT is fabricated with three separately doped regions. The npn device has one p region between two n regions and the pnp device has one n region between two p regions. A question about Vce of an NPN BJT in saturation region. Below is an NPN transistor symbol and the voltages at its terminals are Vb, Vc and Ve with respect to the ground: I read that: during the saturation the Vce = (Vc-Ve) settles to around 0.2V and the further increase in base current will not make Vce zero.1. Saturation의 조건 BJT가 Saturation영역에서 동작하려면 Vcb Vce 여야 한다. 이렇게 되면 베이스-에미터와 베이스-콜렉터 모두 Forward Bias가 된다. 2. I/V …A BJT is obviously more complicated than your equation(s) provide. But those equations are often good enough when just considering the forward active region. To get a feel for the simplest DC model that was developed, see my answer to Why is Vbc absent from bjt equations?.So for a BJT to act as an open switch, all you need to do is to make sure that its base-emitter junction is not forward-biased. Now, for a BJT to act as a closed switch, it needs to operate in the saturation region. In figure 8, we’ve assumed that the npn BJT is operating in the saturation region.In this video, how the transistor (BJT) acts as a switch is explained with an example. Along with that, it is also explained, how to identify the saturation ...• Bi lBipolar JtiJunction TitTransistor (BJT) (C t’d)(Cont’d) – BJT operation in saturation mode –PNP BJT – Examples of small signal models Reading: Chapter 4.5‐4.6 EE105 Spring 2008 Lecture 4, Slide 1Prof. Wu, UC Berkeley Bipolar Transistor in Saturation EE105 Spring 2008 Lecture 4, Slide 2Prof. Wu, UC BerkeleyThe reverse saturation current in the collector-base junction is origined by the diffusion of minority carriers from the neutral regions to the depletion region. It is very dependent from specific parameters of the junction itself, such as the donor and acceptor concentrations, the diffusion coefficients of holes and electrons, the cross ...• Bi lBipolar JtiJunction TitTransistor (BJT) (C t’d)(Cont’d) – BJT operation in saturation mode –PNP BJT – Examples of small signal models Reading: Chapter 4.5‐4.6 EE105 Spring 2008 Lecture 4, Slide 1Prof. Wu, UC Berkeley Bipolar Transistor in Saturation EE105 Spring 2008 Lecture 4, Slide 2Prof. Wu, UC Berkeley Saturation Region: In saturation region, both of the junctions of the BJT are in forward bias. This region is used for the ON-state of a switch where; i c = i sat. I sat is the saturation current & it is the maximum amount of current flowing between emitter and collector when BJT is in saturation region. Since both junctions are in forward bias ...1. Here's a typical Ic vs Vce diagram showing the saturation region of a BJT. In this case if Ib is set at 20uA and Vce varies between 0 and 2V you can clearly see that Ic will also vary from about 12mA (Vce=2V) to about 8mA @ Vce = 0.5V (very non linear) to 0mA @ Vce = 0V.The definition of “saturation region” or “ON mode” when using a bipolar NPN transistor as a switch as being, both the junctions are forward biased, IC = Maximum, and VB > 0.7v. For a PNP transistor, the Emitter potential must be +ve with respect to the Base. This is the working of the transistor as a switch.This region is known as an area of extreme saturation. Complete step by step solution: Bipolar junction transistor (BJT): BJT is Bipolar Junction Transistor's ...Jun 11, 2007 · 0. vce (sat) it means that the voltage of Vce is 0.6 in saturation mode of bjt. if. Ibβ>Ic BJT is in saturation. in active region. Ib = βIc. remove the bjt from the circuit then calculate the voltage across Vbe if Vbe is smaller than 0.7 (or threshold voltage of bjt) the BJT is in cutoff mode. Jun 12, 2007. Saturation Region: In saturation region, both of the junctions of the BJT are in forward bias. This region is used for the ON-state of a switch where; i c = i sat. I sat is the saturation current & it is the maximum amount of current flowing between emitter and collector when BJT is in saturation region. Since both junctions are in forward bias ...SATURATION REGION (FULLY ON) A transistor is said to be saturated (Fully ON) when it is biased in such a way that current passes from the Emitter (E) to the Collector (C). In NPN and PNP bipolar junction transistors (BJTs), connecting the base (B) to the collector (C) makes the PN-junction from the base (B) to the emitter (E) to be forward bias.PNP BJT: Circuit Level Parameters B E C VCB=0 +-+-IC = FIE = FIB IE IB Current gain F: Current gain of the BJT in the forward active operation is defined as the ratio of the collector and base currents: C F B n aE E dB B p B C F I I D N W N W D I I Typical values of F are between 20-200 and: F: In the forward active operation F is defined asFeb 17, 2017 · BJT는 Bipolar Junction Transistor의 약자로서 반도체 3개를 합쳐놓은 전류증폭소자! BJT (Bipolar Junction Transistor)에는 PNP형과 NPN형이 있으며, 베이스 (B), 컬렉터 (C), 에미터 (E) 3개의 전극을 가지고 있어~!! 그리고 BJT와 MOSFET이 있는데, BJT 의 전류는 전자와 정공 (양공) 둘다 ... • In order to prevent the BJT from entering very deeply into saturation, the collector voltage must not fall below the base voltage by more than 400 mV. V CC I C R C (V BE 400mV) A linear relationship can be derived for VCC and RC and an acceptable region can be chosen. Deep Saturation An npn BJT having reverse saturation current Is= 10 15 A is biased in the forward active region with VBE = 700 mV. The thermal voltage VT is 25 mV and the ...19 thg 11, 2014 ... It will not increase the BOM cost anyway. You may also interested on these topics: 1. How to know if a transistor is saturated · 2. BJT ...A bipolar junction transistor ( BJT) is a type of transistor that uses both electrons and electron holes as charge carriers. In contrast, a unipolar transistor, such as a field-effect transistor (FET), uses only one kind of charge carrier.BJT operation in saturation mode PNP BJT Examples of small signal models Reading: Chapter 4.5‐4.6 Bipolar Transistor in Saturation When collector voltage drops below base voltage and forward biases the collector‐base junction, base current increases and the current gain factor, β, decreases.PNP transistor is another type of Bipolar Junction Transistor (BJT). The structure of the PNP transistor is completely different from the NPN transistor. The two PN-junction diodes in the PNP transistor structure are reversed with respect to the NPN transistor, such as the two P-type doped semiconductor materials are separated by a …The transistor can be used as a switch if biased in the saturation and cut-off regions. This allows current to flow (or not) in other parts of a circuit. Because a transistor ’s collector current is proportionally limited by its base current, it can be used as a sort of current-controlled switch. Apr 2, 2021 · Then just do nodal analysis and verify that current is flowing the correct way for a BJT in saturation. EDIT: This answer is for a saturated BJT. But the circuit shows an unusually biased BJT that is is actually not saturated, and probably more accurately described by two BJTs from base to collector and emitter, respectively. Saturation Mode. As V IN increases, the base current increases and therefore so does the collector current. Eventually, the collector resistor R C will drop so much voltage that the BC junction will begin to enter the forward-bias region. When both the BE junction and the BC junction are forward-biased, the transistor is in saturation mode. The ...Apr 2, 2021 · Then just do nodal analysis and verify that current is flowing the correct way for a BJT in saturation. EDIT: This answer is for a saturated BJT. But the circuit shows an unusually biased BJT that is is actually not saturated, and probably more accurately described by two BJTs from base to collector and emitter, respectively. The definition of “saturation region” or “ON mode” when using a bipolar NPN transistor as a switch as being, both the junctions are forward biased, IC = Maximum, and VB > 0.7v. For a PNP transistor, the Emitter potential must be +ve with respect to the Base. This is the working of the transistor as a switch.7. Let's look at the datasheet for an MMBT3904, just for example. The absolute maximum section talks mostly about maximum voltage differences, and a single current limit - the collector current. I'm used to using these, and similar BJTs as saturated switches. And I get that once you have a base current that is sufficient that the Hfe causes the ...Lecture 10: BJT Physics 16 Simplified Circuit Mode Saturation Region • In the saturation region, both junctions are forward-biased, and the transistor operates with a small voltage between collector and emitter. v CESAT is the saturation voltage for the npn BJT. No simplified expressions exist for terminal currents other than i C + i B = i E.The transistor can be used as a switch if biased in the saturation and cut-off regions. This allows current to flow (or not) in other parts of a circuit. Because a transistor ’s collector current is proportionally limited by its base current, it can be used as a sort of current-controlled switch.The transistor can be operated in three modes: Cut-off mode. Saturation mode. Active mode. In order to operate transistor in one of these regions, we have to supply dc voltage to the npn or pnp transistor. Based on the polarity of the applied dc voltage , the transistor operates in any one of these regions. Oxygen saturation refers to the level of oxygen found in a person’s blood, as indicated by the Mayo Clinic’s definition of hypoxemia. A healthy person’s blood is maintained through a certain oxygen saturation range to adequately deliver oxy...The minimum base current the BJT needs for saturation is: I B(min) = I C(sat) / ẞ (eq. 9) Note that I B should be significantly greater than I B(min) to be sure the BJT stays well into saturation. Finally, some inquisitive readers may be asking if there is a formula for V CE(sat). Indeed, there is, but as we’ve mentioned this quantity can ... Particularly, the Is saturation according to this SPICE description varies with temperature like this: What troubles me is the 1/(T1-T0) term in the exponent. Say, the saturation current is measured at 25 degrees celsius, then, when we try to determine the Is at that temperature we get Exp[1/0], which is an obvious singularity.Figure 1. Transistor DC beta with respect to changes in I C and temperature. The second parameter of BJT is the DC Alpha ( αDC ). It is the ratio of the DC collector current and the DC emitter current. However, the DC Alpha ( αDC) parameter is rarely used in transistor circuits, particularly compared to the DC beta ( βDC) parameter.The transistor going into saturation isn't a property of the transistor itself, but instead a property of the circuit surrounding the transistor and the transistor, as part of it. A question about Vce of an NPN BJT in saturation region. For this circuit with ideal transistor (current controlled current source CCCS) any base current large than:• Forward and reverse active operations, saturation, cutoff. • Ebers-Moll ... becomes too large), the BJT will go into the saturation region (in the saturation.The Darlington Transistor named after its inventor, Sidney Darlington is a special arrangement of two standard NPN or PNP bipolar junction transistors (BJT) connected together. The Emitter of one transistor is connected to the Base of the other to produce a more sensitive transistor with a much larger current gain being useful in applications …Jan 26, 2021 · Bjt Explanation Saturation. Yes, this is correct. The electric field of the depletion region (between the two junctions) can accelerate the charge carriers in the same direction as the diffusion current, and this current will be the collector-emitter current. Jan 26, 2021. #1. (i) Saturation Region In this region, both BJT junctions are forward biased. V CE is small, e.g. 50-100 mV, but quite large collector and base currents (I C & I B) can ow. This region is not used for ampli cation. There is a low resistance between the C and E terminals; the BJT acts like a closed switch. Figure 4 shows an actual circuit of a BJTSaturation Region Cuto Region As long as v CE >v CEsat, BJT is in active region. v CEsat = 0.2 V. If v CE falls below v CEsat, BJT will enter into saturation region. S. Sivasubramani EE101 - BJT 8/ 60This introduces an extra delay, called storage time, to the operation of a BJT employed as a switch. After the storage time, the transistor comes out of saturation and the output of the transistor starts to respond to the input. If appropriate resistor values are chosen, ECL logic prevents transistors from entering saturation.• Forward and reverse active operations, saturation, cutoff. • Ebers-Moll ... becomes too large), the BJT will go into the saturation region (in the saturation.It is necessary to operate BJT as a switch in power converters. The drive should be such that BJT is driven in saturation and cut-off with short switching times. This makes operation Of BJT faster. Also it is necessary to protect the BJT against various faults such as overcurrent, overvoltage etc. The driver circuit takes care Of all these faults.Figure 3: In Saturation, Collector and Emitter are Nearly Shorted Together Using the two states of cutoff and saturation, the transistor may be used as a switch. The collector and emitter form the switch terminals and the base is the switch handle. In other words, the small In cut off region, both emitter to base and base to collector junction is in the reverse bias and no current flows through the transistor. The transistor acts as an open switch. In the saturation region, both the junctions are in forwarding bias, and the transistor acts as a closed switch. In cut off region the output of the transistor VCE, IC ...Apr 3, 2011 · A Schottky diode is integrated into the transistor from base to collector. When the collector gets low when it's nearly in saturation, it steals base current which keeps the transistor just at the edge of saturation. The on state voltage will be a little higher since the transistor isn't fully saturated. A bipolar junction transistor is a three-terminal semiconductor device that consists of two p-n junctions which are able to amplify or magnify a signal. It is a current controlled device. The three terminals of the BJT are the base, the collector, and the emitter. A signal of a small amplitude applied to the base is available in the amplified ... With both junctions forward biased, a BJT is in saturation mode and facilitates high current conduction from the emitter to the collector (or the other direction in the case of NPN, with negatively charged carriers flowing from emitter to collector). See morewe push the BJT into saturation, right? A: NO!! There is a big problem with this strategy as well! Remember, it is the total input voltage that will determine the BJT curve. If we DC bias the amplifier so that it is nearly in saturation, then even a small voltage v i can “push” the BJT into saturation mode. i C CE v CC C V R V CC active I C ...As you can see on the datasheet below for the 2n2222a NPN transistor, the "Collector-Emitter Saturation Voltage" and "Base-Emitter Saturation Voltage" are defined respectively as 0.3 to 1.0 and 1.2 to 2.0. I believe I understand transistor saturation, but whats the difference between Collector-Emitter Saturation and Base-Emitter Saturation?It's due to the temperature variation in the saturation current for the device, which has an opposite sign and greater magnitude than the Shockley equation provides. Shockley Equation. As I'm sure you can find repeated, in many places, the simple Shockley equation that operates reasonably well for a BJT in active mode: ... Once you have included the …The yellow region is the "linear", or "ohmic", or "triode" region. In the saturation region, the thick horizontal (well, slightly tilting upwards) straight lines (well, OK, curves) represent the (connected) points in the region of a particular Vgs value. So for example, the curve that the red dot sits represents the points of Vgs = 2.5V.The BJT (7.1) BJT Physics (7.2) BJT Ebers-Moll Equations (7.3) ... Saturation Region (Low Output Resistance) Reverse Active (Crappy Transistor) Breakdown Linear Increase. Explanation: If the collector-base junction and the base-emitter junction are both forward-biased, then the BJT functions in the saturation region of the output characteristics. 5. In a BJT, if the collector-base junction and the base-emitter junction are both reverse-biased, which region is the BJT operating in? a) Saturation region b) Active region c) Cutoff region22 thg 5, 2022 ... 1: The Saturating Switch. A good example of this is the saturating LED driver circuit shown in Figure 4.7.1 ...If it's a miss, the solution values usually hint at the actual mode of operation—e.g., one assumes forward-active mode, but the solution values indicate the transistor cannot be in forward-active mode and is probably in saturation mode; so next you attempt a solution under the assumption the transistor is operating in saturation mode.此時IC = βIB,電晶體工作於線性放大區,IC受控於IB,BJT可當成一訊號放大器。 三、飽和模式(Saturation):VBE 及VBC均為順偏。連續提升IB值令使受控之IC到達一個最大的上限值,當此之時,續增IB已無法令IC再增其值,且說此BJT已達飽和狀態,現時之IC記為IC(sat)。A BJT is obviously more complicated than your equation(s) provide. But those equations are often good enough when just considering the forward active region. To get a feel for the simplest DC model that was developed, see my answer to Why is Vbc absent from bjt equations?.Jan 22, 2016 · 2. You believe that when Vce is less than Vce (sat) you cannot be in saturation. This is incorrect. In saturation, Vce can be less than or equal to Vce sat. Really, the way to look at it is this: If the base emitter junction is forward biased AND the base collector junction is also forward biased, then the transistor is in saturation. This creates \(I_B\). If properly designed, this current will be sufficient to put the BJT into saturation. The BJT acts as a switch, completing the circuit between the DC supply, the LED and the current limiting resistor, \(R_C\). For this to work reliably, we have to make sure that the ratio of saturation current to base current is much less ... The reverse saturation current in the collector-base junction is origined by the diffusion of minority carriers from the neutral regions to the depletion region. It is very dependent from specific parameters of the junction itself, such as the donor and acceptor concentrations, the diffusion coefficients of holes and electrons, the cross ...12/3/2004 Example A BJT Circuit in Saturation 1/7 Example: A BJT Circuit in Saturation Determine all currents for the BJT in the circuit below. 10.0 K 2.0 K 5.7 V 10 K 10.7 V β = 99 Hey! I remember this circuit, its just like a previous example. The BJT is in active mode! Let's see if you are correct! ASSUME it is in active mode and ENFORCE V4 Answers Sorted by: 18 Saturation simply means that an increase in base current results in no (or very little) increase in collector current. Saturation occurs when both the B-E and C-B junctions are forward biased, it's the low-resistance "On" state of the device.PNP BJT: Circuit Level Parameters B E C VCB=0 +-+-IC = FIE = FIB IE IB Current gain F: Current gain of the BJT in the forward active operation is defined as the ratio of the collector and base currents: C F B n aE E dB B p B C F I I D N W N W D I I Typical values of F are between 20-200 and: F: In the forward active operation F is defined as Figure 3: In Saturation, Collector and Emitter are Nearly Shorted Together Using the two states of cutoff and saturation, the transistor may be used as a switch. The collector and emitter form the switch terminals and the base is the switch handle. In other words, the small BJT Transistor as a Switch, Saturation Calculator. BJT Transistor as a Switch, Saturation Calculator is an Online Calculator to calculate Transistor as a Switch automate. Introduction of BJT Transistor Definition of BJT Transistor . The Bipolar Junction Transistor shorts for BJT. And BJT is a semiconductor device with a 3-layers, 3 terminals ...β = α/ (1-α) From the above equations the relationship between α and β can be expressed as. α = β (1-α) = β/ (β+1) β = α (1+β) = α/ (1-α) The β value may vary from 20 to 1000 for low power transistors which operate with high frequencies. But in general this β value can have the values in between the range of 50-200.• Bi lBipolar JtiJunction TitTransistor (BJT) (C t’d)(Cont’d) – BJT operation in saturation mode –PNP BJT – Examples of small signal models Reading: Chapter 4.5‐4.6 EE105 Spring 2008 Lecture 4, Slide 1Prof. Wu, UC Berkeley Bipolar Transistor in Saturation EE105 Spring 2008 Lecture 4, Slide 2Prof. Wu, UC BerkeleyA bipolar junction transistor ( BJT) is a type of transistor that uses both electrons and electron holes as charge carriers. In contrast, a unipolar transistor, such as a field-effect transistor (FET), uses only one kind of charge carrier.PNP BJT: Circuit Level Parameters B E C VCB=0 +-+-IC = FIE = FIB IE IB Current gain F: Current gain of the BJT in the forward active operation is defined as the ratio of the collector and base currents: C F B n aE E dB B p B C F I I D N W N W D I I Typical values of F are between 20-200 and: F: In the forward active operation F is defined as History of Bipolar Junction Transistors. The transistor (BJT) was not the first three terminal devices. Before transistors came into existence vacuum tubes were used. In electronics, vacuum tube triodes were used almost for half a century before the BJT’s.The light bulb invented by Thomas Edison in the early 1880’s was one of the first uses of vacuum tubes for any …History of Bipolar Junction Transistors. The transistor (BJT) was not the first three terminal devices. Before transistors came into existence vacuum tubes were used. In electronics, vacuum tube triodes were used almost for half a century before the BJT’s.The light bulb invented by Thomas Edison in the early 1880’s was one of the first uses of vacuum tubes for any …Which quantity is getting saturated in so called 'saturation region' of BJT ? Obviously the collector current. It can be seen very clearly from the output characteristic graph that as you decrease the collector to emitter voltage, the corresponding current increases with reference to the DC load line.SATURATION REGION collector current flows even when the external applied voltage is reduced to zero. There is a low barrier potential existing at the collector – base junction and this assists in the flow of collector current (II) COMMON – EMITTER CONFIGURATION The input is connected between base and emitter, while output is connected. This introduces an extra delay, called stBJT. MOSFET. BJT is PNP or NPN: MOSFET is N-type or P-type: BJT is Lecture 10: BJT Physics 16 Simplified Circuit Mode Saturation Region • In the saturation region, both junctions are forward-biased, and the transistor operates with a small voltage between collector and emitter. v CESAT is the saturation voltage for the npn BJT. No simplified expressions exist for terminal currents other than i C + i B = i E. This is the Multiple Choice Questions in DC Biasing – BJTs from th Oct 31, 2015 · With Vin = 5V, VB = 0.746V and VC = 0.024V which means that the BJT is operating in the saturation region. But I don't understand why. Vcc = 5V and Vin = 5V. RB = RC = 1k ohm. So I expect that VB = VC and the base-collector junction is reverse biased which means that the BJT is in the forward-active region. 27 thg 1, 2020 ... When load line intersect I...

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