Norton equivalent circuit examples. So, below, we have a circuit that we will break down.
Norton equivalent circuit examples 5 days ago · Maximum Power Transfer Example. Oct 20, 2021 · In our example this will be 69. Common examples are the ubiquitous 3. k. The impedance is the same in both Thevenin and Norton Equivalent Circuits, so we already determined Z and now just need to determine the current source. An equivalent circuit, as its name implies, is a circuit which can be used as a model of a device, a system or another circuit since it has the same behaviour (inputs and outputs), as far as the variables of interest are concerned, as the actual device etc. 5 days ago · For the Thevenin equivalent, the open-circuited voltage would equal the Thevenin source voltage, which is 11. As you might expect, ECE 1250 Lecture 5 & 6 notes p5 Thévevin & Norton Examples Ex 2 Find the Thévenin equivalent: R1 40. Q. 1. Jun 6, 2021 · Indeed, if a Thévenin equivalent is found, a source conversion can be performed on it to yield the Norton equivalent. Finding the Norton Equivalent Resistance: STEP 1: Take out the load. A time-independent elements is one for which we can plot an i/v curve. Open-circuit test: terminate the circuit with an open circuit and find the open-circuit voltage, šš. Just as with Thevenin's Theorem, the qualification of ālinearā is identical to that found in the Superposition Theorem: all underlying equations must be linear (no exponents or roots). One path passes through the equivalent resistance and the second path passes May 2, 2021 · Example-1 Find the Norton Equivalent Circuit Across Terminals AB. So, the scary-looking circuit on top can be reduced to the equivalent circuit on the bottom. Edward Lawry Norton. The key steps are: 1) Find the open-circuit voltage Practice reducing a circuit to its Thevenin or Norton Equivalent In the previous section we see how to find the Thevenin or Norton Equivalent Circuit for a complex linear circuit. Again, the two resistors are connected in parallel across the terminals A and B which gives us a total resistance of:. 8 ohm; 3. 882 A 13. Now we will study the meaning of this statement just as in source transformation, V Th is the open-circuit voltage while I N is the short circuit current. Applying Theveninās theorem allows us to simplify any linear circuit to its Thevenin equivalent circuit with a single voltage source and series resistance. To calculate I N, we need to short-circuit the terminals AB. Convert the circuit below into its Thevenin equivalent circuit at terminals a-b. Salem § Example 1: Find the Thevenin equivalent of the highlighted sub-circuit ⢠Therefore, to find the Thevenin voltage (V Th), calculate the open-circuit voltage in the original sub-circuit Equivalent Circuits Figure 3. Norton Equivalent Circuit zFinding a Norton equivalent circuit requires essentially the same process as finding a Thevenin equivalent circuit. Thevenin: Replace circuit with VOC in series with RTh Norton: Replace circuit with ISC in parallel with RTh Note: for circuits containing no independent sources the equivalent network is merely RTh , that is, no voltage (or current) source. Example of Norton's Theorem. So, below, we have a circuit that we will break down. For the Norton Equivalent Circuit we need to find Rn and In. Circuit theorems/Network theorems Learn how to use Norton's theorem to simplify complex linear circuits to a current source and a resistor in parallel. Redraw the circuit below into its Norton equivalent circuit at terminals a-b. The behavior of the original Network and the Norton equivalent circuit are identical with respect to points A and B. You May Also Read: Theveninās Theorem with Solved Examples; Nortonās Short Circuit Current. # To calculate a circuit's Thévenin equivalent: 1) Remove the load and calculate the open-circuit voltage where the load used to be. Second, modify the original circuit so that there is no load connection between these two nodes (for example, by removing a resistor that now corresponds to a load resistor Finding the Norton Equivalent Circuit. 2. In the above equivalent circuit, 2 days ago · Learn how to apply Norton's Theorem and find Norton's equivalent circuit for any two-terminal network with resistances and sources. # VS 20. Where I N is the short-circuit current through the terminal load resistor and R N is the equivalent resistance at the terminals when all the independent sources This electronics video tutorial on electrical circuit analysis provides a basic introduction into Norton's theorem and touches on Thevenin's theorem. Q For the given network, find the current I Apr 3, 2024 · Thevenin and Norton equivalent circuits as shown in Figure 14 +-13. Calculate the load current and voltage for the 6-Ī© load resistor R L. Example \(\PageIndex{3}\) Let's reexamine Example \(\PageIndex{1}\), this time creating a Norton equivalent 2 days ago · This article covers Norton's Theorem and Nortonās Equivalent Circuit Parameters such as Norton's Equivalent Resistance and Short-circuit Current along with Nortonās Theorem Solved Problem with Dependent Sources. You May Also Read: Nortonās Theorem with Solved Examples; How to Find the Equivalent Voltage of a Thevenin Circuit? Nortonās Theorem in Network Theory - Learn about Nortonās Theorem in Network Theory, its applications, and step-by-step analysis to simplify complex electrical circuits. Circuit B (which is often called a load) may consist of many circuit elements, a single element (a load resistor), or no element. The current is only a function of the voltage, it does not depend on the rate of change of the voltage. With the Norton equivalent circuit and no load resistor, all 14 A from the Norton current source would Nov 25, 2022 · Theveninās theorem is used to solve the complex circuits consisting of several sources and impedances by converting them into a simple equivalent circuit called Theveninās equivalent circuit. The Norton Equivalent current source is the short circuit current flowing between the nodes of interest, which are A and B for this example. Solution. ) Jan 30, 2023 · Thevenin / Norton equivalent circuits We have seen many instances where we can take elements in a part of a circuit and combine them in some fashion to make an represents a place where we intend to connect another circuit. Norton theorem Example based on the DC circuit. Next: A/C Response of Capacitor Previous: Thevenin's Theorem Oct 1, 2014 · To illustrate, letās find Nortonās equivalent circuit for the circuit below. Draw the Equivalent Circuit. Step-1 Remove R L =4Ī© branch. So this 8. Introduction to Nortonās Theorem Named after Edward Lawry Norton, an Mar 10, 2022 · The document discusses Thevenin's theorem for circuit analysis. For the circuit shown, R 1 = 82 Ī©; R 2 = 47 Ī©; R 3 = 47 Ī©; R 4 = 12 Ī©; V S = 16 V; β = 1. Thevenin and Norton equivalent circuits can be applied to AC circuits in a manner similar to how they are applied to DC circuits. 1 ohm output resistance and is driving a 8 May 22, 2022 · Indeed, if a Thévenin equivalent is found, a source conversion can be performed on it to yield the Norton equivalent. You can see how the norton's equivalent circuit forms a current divider circuit between the norton equivalent resistance and the resistance of the load. 6: 12 V A B 0. See examples with dependent and independent sources, and how to calculate Norton's 23 hours ago · Norton's theorem states that any complex linear circuit can be simplified to an equivalent simple circuit with a single current source in parallel with a single resistor connected to a load. Examples are Jun 5, 2021 · Thevenin's theorem is a circuit theory that states any complex circuit or network can be reduced to a simple network that has a voltage source (Called Thevenin's Voltage) connected in series with total circuit equivalent resistance (Called We can redraw the circuit into its Thevenin equivalent circuit as shown below. Step 1: Find Theveninās resistance. V R2 120. As a result, I sc = V oc R o Example 1 A 32V audio ampliļ¬er has a 0. Nortonās equivalent circuit consists of a Norton equivalent resistance and Norton current source connected in parallel with the load. 2 V in our example. Mar 1, 2021 · Nortonāstheoremstates that a lineartwo-terminal circuit can be replaced by an equivalent circuit consisting of a current source iNin parallel with a resistor RN, where iNis the short-circuit current through the terminals and RNis the input or equivalent resistance at the terminals when the independent sourcesareturnedoff. Jan 15, 2014 · Theveninās Theorem in DC Circuit Analysis. We have one voltage source so letās short it. This is the Method 3 for finding a Thevenins equivalent circuit. While calculating the theveninās equivalent resistance, all voltage sources must be turned off, meaning it acts like a short circuit and all current sources act like an open 5 days ago · This page will walk you step-by-step through the process of determining the Thevenin equivalent circuit. However, the same advantages seen with Theveninās Theorem apply to Nortonās as well: if we wish to analyze load resistor voltage and current over several different values of Jul 16, 2019 · Nortonās Equivalent Circuit Example 1. Jan 19, 2018 · Ch. Procedure to find the Norton Equivalent Circuit: 1. This simplification can make it easier to evaluate the effects of changing the connected load. Find the current in the resistor R if its resistance is: 1. Ok, so far so good, but we now have to solve with the original 40Ī© load resistor connected across terminals A and B as shown below. Theveninās Theorem (also known as HelmholtzāThévenin Theorem) is not by itself an analysis tool, but the basis for a very useful method of simplifying active circuits and complex networks. Any two terminal network containing linear, passive and active elements may be replaced by an equivalent current source I N in parallel with a resistance RN where IN is the current flowing through a short Feb 24, 2025 · Linear Circuits Analysis. Once found, the Norton equivalent circuit can be used to calculate currents in other parts of the original circuit. Cite as: Anant Agarwal and Jeffrey Lang, course materials for 6. Choosing the one to use depends on the application, not on what is actually inside the circuit. Jan 30, 2023 · Thevenin & Norton practice problems Refresh the page to get a new problem. In DC circuit, While not as popular as Thevenin circuits for whatever reason, Norton Equivalent Circuits are a staple in beginning circuits courses. . One way to Thévenize t Nov 12, 2018 · Norton Equivalent, example #2: ⢠Find the Norton Equivalent Circuit at 60 Hz. Using the example circuits from the last two sections, With the Norton equivalent circuit, all 14 amps from the Norton current source would have to Feb 7, 2018 · Norton Example. Let us understand Theveninās Theorem with the help of an example. Use the calculated value for Norton current and Norton resistance to draw the equivalent circuit as shown in figure 8. . Problem: Derive the Norton equivalent circuit for the simple resistive network circuit shown in Figure 2. 19. For finding the voltage across the load resistance we reconnect our original resistance 2 Ī©, and analysis the circuit as a simple circuit. Example: 09/03/2016 6 ā if nothing is connected across the output no current will flow in R2 so Example: Théveninās theorem is useful for solving the Wheatstone bridge. For this case we will go with a current source with nodal analysis. 4mA. (Recall that the "short-cut" method cannot be used to find equivalent resistance when the circuit has Dec 6, 2024 · These circuits demonstrate Norton's theorem, which states that any combination of voltage sources, current sources, and resistors can be reduced to a single current source and a single resistor. Norton Equivalent Circuit Example. If the circuit has sources operating at different frequencies (will be shown in the example below), the Thevenin or Norton equivalent circuit has to be determined at each frequency. It exp Problem: Letās find the Theveninās equivalent circuit for the above circuit. a. For finding the voltage across the load resistance we reconnect our original resistance 2 Ī©, and analysis the circuit as Mar 12, 2024 · As shown in the Norton equivalent circuit, the Norton current is divided into two paths. This theorem is useful to quickly Theveninās Theorem Example. Now letās look at the statement. L Thevenin, made one of these quantum leaps in 1893. MIT Dec 16, 2002 · called a Norton equivalent circuit. Now reconnect the load to the Nortonās equivalent circuit and calculate the current, voltage and power associated with the load as. Develop the Norton equivalent circuit and find the unknown parameter. Dec 16, 2024 · THE EQUIVALENT CIRCUITS THÉVENIN AND NORTON Nov 9, 2017 · Alex "The Boy" tells us how to use Norton's Theorem to convert a regular circuit into its Norton Equivalent. ) 1. 5. See a step-by-step example with verification and a summary of the theorem. Solution: Step 1: To calculate I SC: Short circuit A and B terminals to get the following circuit. This will be the same as for the Thévenin case since an ideal current source has infinite resistance. Determine the Théveninequivalent of network A, and compute the power delivered to the load resistor RL. Find the current flowing through 20 Ω Mar 12, 2024 · Norton Equivalent Circuit Example. Like all models their validity is confined to a particular range of the parameters. 75Ī© resistor. port) resistance of network seen Norton equivalent TH TH N R V I = RTH =RN IN J. For this example, that entails shorting the voltage source V ^ s and opening the current source I ^ s. Jun 28, 2022 · The final Norton equivalent circuit looks like this: Determine the voltage across the load resistor . Aug 28, 2024 · EE240 Thevenin and Norton Problems - Solutions - Zubair Khalid Feb 23, 2025 · Nortons Theorem Equivalent Circuit. Contrasting our original example circuit against the Norton equivalent: it looks something like this: after Norton conversion . A French engineer, M. Solution: Step-1: Short the terminals x-y as shown in figure below. Schematic Diagrams & Symbols: https://www. It is important to replace independent sources with their internal resistances 2 days ago · Figure. In the above circuit, we have a voltage source (32V) and another current source (2A). In this section we will go through examples to reinforce Dec 14, 2020 · 1. Step 4. 8 Ī©): With this value of load resistance, the dissipated power will be 39. Because Z 1 is disconnected on the left side, it cannot have any current flow through it and thus has no effect on the equivalent impedance. Step 3: Drawing Norton's equivalent circuit and showing the load resistance RL, we get the following circuit: Example 2 Obtain the Norton's equivalent circuit at the terminals A and B for the network shown. 3 All circuits containing sources and resistors can be described by simpler equivalent circuits. 5; Find the Thevenin equivalent of the circuit at the port defined by the nodes a and b. (b) Fig. It provides examples of using the theorem to find the equivalent Thevenin circuit for more complex networks. 17 6 517 223 3263 Jan 11, 2022 · The Norton equivalent current, In, for this sample network is equal to 80 mA. 6. 5-mm stereo audio jack and the even more ubiquitous USB plug. The basic difference between these two is that Nortonās theorem provides an equivalent current source, having an equivalent resistance Apr 16, 2025 · Dive into Norton's theorem with solved problems to solidify your understanding of circuit analysis. Mar 28, 2024 · This resistance is equivalent Nortonās resistance RN or (impedance ZN). This video explains how to calculate the current flowing through a load resistor using thevenin's theorem. In direct-current circuit theory, Norton's theorem, also called the MayerāNorton theorem, is a simplification that can be applied to Oct 1, 2015 · The basic procedure for finding a Thevenin equivalent circuit is the following: First, determine which nodes in your original circuit will correspond to the Thevenin circuit's two output terminals. 2 In the given network draw Nortonās equivalent circuit and find the current through 18. Solution: Replace all the independent sources with their inner resistances. Theveninās Theorem states that āAny linear bilateral circuit containing several voltage sources and impedances can be replaced with an As such, Thevenin and Norton resistances for the same original network must be equal. Thevenin Theorem Example-1. Thus. 12 Norton theorem & maximum power transfer theorem Page 2 The Norton and Thévenin equivalent circuits can also be found from each other by using the source transformation Fig. Dec 23, 2002 · Thevenin/Norton Analysis 3. The Norton equivalent circuit. Taking our Thevenin equivalent example circuit, the Maximum Power Transfer Theorem tells us that the load resistance resulting in greatest power dissipation is equal in value to the Thevenin resistance (in this case, 0. ā Step 1-Short circuit the load Dec 1, 2021 · By determining the equivalent Thévenin or Norton circuits in relation to the load to connected taking into account the pre-developed special bench systems on the example of an external gear Mar 21, 2024 · A Norton equivalent circuit is a current source in parallel with a resistor, representing a linear, two-terminal network. Nortonās Theorem with Solved Examples ā Similar to Theveninās theorem, Nortonās theorem is also a method for converting complicated circuits into simple circuits thereby getting an easy solution. So far we have explored time-independent (resistive) elements that are also linear. Norton Thoerm circuit consisting of a current source, I N, in parallel with a Norton resistor R N. Furthermore, from the equivalent circuit the maximum voltage that can be obtained across RL is 8 V and corresponds to RL = ā. Oct 11, 2015 · Zac Sutton of UConn HKN determines the Thevenin and Norton Equivalents of an electrical circuit. Find Norton equivalent circuit across terminals AB in given active linear network shown in below figure. 3. V TH =v oc I N = i sc R TH = v oc / i sc = R N Example: Find the Norton equivalent circuit at the terminals a & b. Replacing a network by its Norton equivalent can simplify the analysis of a complex circuit. This leads to entirely different equivalent circuits, one for each frequency, not one equivalent circuit Jan 16, 2014 · As with the Thevenin equivalent circuit, the only useful information from this analysis is the voltage and current values for R 2; the rest of the information is irrelevant to the original circuit. (by Kim, Eung) Thevenin's Theorem states that we can replace entire network by an equivalent circuit that contains only an independent voltage source in series with an impedance (resistor) such that the current-voltage relationship at the load is unchanged. Still don't get it? Have questions relating to this topic or 5 days ago · In the second section, we propose a step by step method to follow in order to determine Nortonās equivalent model of a circuit. # RL 60. This is the Thévenin voltage (V Apr 15, 2019 · While calculating Norton resistance or impedance, all independent sources are set to zero (voltage source replaced by short circuits and current source replaced by open circuits). Statement. Jun 1, 2018 · Nortonās theorem says that a linear two-terminal electric circuit may be exchanged with a Norton equivalent circuit. We do both calculations without RL. Mar 27, 2024 · Example, Consider the circuit shown in (Fig. Let us consider a few simple Norton May 9, 2024 · Norton's theorem states that any linear circuit can be simplified to an equivalent circuit consisting of a single current source and parallel resistance that is connected to a load. Just like the example before, we will energize the circuit with either 1 V voltage source or 1 A current source. Another example of Nortons theorem: Find out the Norton equivalent circuit. Superposition, Thevenin /Norton Equivalent circuits So far we have explored time-independent (resistive) elements that are also linear. Nortonās Theorem Problems with Solutions. 6: A B Thevenin s Equivalent Norton s Equivalent Figure 14 Q 2019-DEC)Determine the current through the load resistance using Nortonās theorem for the circuit shown in Figure 15. Converting equivalent sources is useful to reduce the number of mesh currents or node voltages in a circuit. Step-1 Find Norton Sep 13, 2022 · Page 3 of 6 Relationship between V oc and I sc Since the Thevenin equivalent and Norton equivalent are both equal to the original circuit, they too must be equivalent. 9mA. Read the Thevenin-Norton class notes. ) 0 ohm; 2. 4 Thévenin and Norton equivalent circuits. Nortonās Theorem. Example 1. Example: Step 1: For the analysis of the above circuit using Theveninās theorem, firstly remove the load resistance at the centre, in this Jan 30, 2023 · Thevenin / Norton equivalent circuits We have seen many instances where we can take elements in a part of a circuit and combine them in some fashion to make an represents a place where we intend to connect another circuit. Jan 7, 2022 · In this tutorial, letās go over the steps you should follow to create a Norton equivalent circuit and then go through two examples to show those Just as for Theveninās theorem and the superposition theorem, Nortonās theorem is limited to use with linear circuits where all the underlying equations do not include exponents or roots. The resulting Norton equivalent circuit is shown in Figure 5. The voltage across the terminals A and B with the load resistor connected is Nov 19, 2024 · Nortonās Theorem. We can observe the Norton theorem examples with solutions below: 1. 1. Remember that a current source is a component whose job is to provide a constant amount of current, outputting as much or as little voltage necessary to maintain that constant current. 9mA divides into the 2 resistors. ⢠Convert the Norton Equivalent to the Thevenin Equivalent Circuit. Oct 2, 2015 · A Thevenin equivalent circuit consists of a voltage source (V Th) in series with a resistor (R Th) where V Th is the open-circuit voltage at terminals A-B and R Th is the equivalent resistance at terminals A-B. Different real examples will be proposed in a third section in order to illustrate this method. 2 Nortonās Theorem Jan 13, 2020 · Introduction to Electrical Engineering L 7: NETWORK THEOREMS Feb 4, 2025 · Specific superposition example: V1 0 y1 0 equivalent network RTH vTH open circuit voltage at terminal pair (a. Example of Calculating Norton Equivalent Resistance. 002 Circuits and Electronics, Spring 2007. Example \(\PageIndex{3}\) Let's reexamine Example \(\PageIndex{1}\), this time creating a Norton equivalent circuit. Finally, we will draw a link between Nortonās and Theveninās models, before concluding this tutorial. VTh RTh IN R N Example cont. Dec 26, 2023 · The procedure for finding the Norton equivalent circuit involves removing the load, calculating the short-circuit current and equivalent resistance, and replacing the removed portion with the equivalent circuit. Example: Find the Nortonās equivalent circuit to the left of terminal x-y in the shown below. The resulting passive circuit is given in Figure 5. Norton Equivalent of a Thevenin Equivalent# May 15, 2020 · Nortonās Equivalent Circuit: To draw Nortonās Equivalent Circuit, we connect current source I sc in parallel with internal resistance R int. 2: Theveninās Equivalent Circuit. 2 watts: Apr 16, 2024 · This guide will explore Nortonās Theorem, the process of finding the Norton Equivalent Circuit, and its practical applications in circuit analysis. a). šššš. Dec 5, 2024 · Thévenin and Norton Equivalent Circuits Loai G. STEP3: Find the resistance you would measure at the terminals 2. You may already know that the idea behind Thevenin and Norton circuits is that any linear, two terminal circuit can be replaced with an equivalent circuit consisting of Jun 28, 2022 · The final Norton equivalent circuit looks like this: Determine the voltage across the load resistor . Only steps 2 & 4 differ from Thevenin & Norton! Example of Norton's Theorem. Step-1 Find Norton equivalent current (I N). The norton current source is 8. Apr 19, 2025 · Any black box containing resistances only and voltage and current sources can be replaced by an equivalent circuit consisting of an equivalent current source in parallel connection with an equivalent resistance. Calculate RTh(RN) = Voc / Isc 4. The Norton equivalent resistance (R N) is similarly determined by looking into the terminals with the source set to zero. 1 Find the value of current I in the given circuit using Nortonās theorem. Letās consider a simple electrical circuit consisting of two resistors (R 1 = 4Ī© and R 2 = 6Ī©) and a voltage source Apr 11, 2021 · Thevenin Equivalent Circuit Examples Example 1āFind the current passing the resistor R 1. NORTON'S THEOREM. In this example, the Norton current is obtained from the open circuit voltage (the Thevenin voltage) divided by the resistance r. Jan 30, 2023 · Read the Thevenin-Norton class notes. Click/tap the circuit above to analyze on-line or click this link to Save under Windows. 7. STEP2: Short all voltage sources and open circuit all current sources. This example shows how the Norton equivalent simplifies calculations. Example. This equivalent circuit can be seen in Figure 1 below. I N = i sc = 1A v oc / i sc = 4 Ī© R TH = R N Simplifying Linear Circuits. (1) Mar 9, 2016 · Determine Thévenin and Norton equivalent circuits of the following circuit. (b) Converting between Thévenin and Norton equivalent circuits. From this circuit we will get Norton resistance Mar 15, 2024 · Examples of sub-circuits include stages of amplifiers, sections of a power distribution layout, sensors, and microcontrollers. This resistance is the same as the Thevenin resistance, the resistance looking back from AB with V 1 replaced by a short circuit. We have seen that two terminal (one port) circuits can be modeled by simple circuits (Thevenin or Norton equivalent circuits) and that they have a straight line i-v characteristic. Feb 24, 2025 · Introduction and analysis of circuits containing dependent sources. Repeat the calculations for a load resistor of Apr 27, 2020 · Analyzing AC Circuits using Thevenin and Norton Equivalent Circuits. Furthermore, most voltage sources, Nov 25, 2022 · Nortonās equivalent circuit has a single current source called Nortonās current source(IN), an equivalent impedance called Nortonās equivalent impedance Z N, and a load impedance Z L. Insert the resistance (or impedance) in parallel with a current source IN which forms a Nortonās equivalent circuit. Feb 1, 2018 · The Thevenin and Norton equivalent circuits are related by a source transformation. For the circuit shown, R 1 = 47 kĪ©; R 2 = 68 kĪ©; V S = 12 V; Find the Thevenin equivalent of the circuit at the Jan 30, 2006 · Theveninās and Nortonās Equivalent Circuit Tutorial. /, : 9 $ % : : : / 5 $ : Figure 15 First, we can find the equivalent impedance by setting the ideal sources to zero. As part of this Circui Norton's Theorem states that it is possible to simplify any linear circuit, no matter how complex, to an equivalent circuit with just a single current source and parallel resistance connected to a load. Any linear electrical complex circuit can be simplified into simple circuit that consists of a single current source and parallel equivalent resistance connected across the load. Apply KVL in loop-1; (Apply KVL in loop-2; From the current source; Hence; By solving equation-1 and 2; we can find the value of current I 2 which is same as Norton current (I N). A circuit is linear if it uses only standard passive components such as resistors, inductors, and capacitors. EXAMPLE (1) Find the Norton equivalent circuit for the network in the shaded area of Fig. otsdrn zoguygt hsrj jpfgcjs excrp iklyu kcpyohk ktkd zznplt akwvpp rkrga esabg xvpkyx dmpzjpn ivgbcq