From ebdd67edc1fdaa3de56714a7e081bed424ce38e1 Mon Sep 17 00:00:00 2001 From: fischerl Date: Mon, 30 Jan 2012 14:16:42 -0500 Subject: [PATCH] added lecture 2 subs --- subs/27GsG_REo_w.srt.sjson | 5 + subs/38euKuG1cUs.srt.sjson | 5 + subs/3g8ZeZlpv8E.srt.sjson | 62 +++++ subs/3nCyei-6rtk.srt.sjson | 140 ++++++++++ subs/BUsj70M8ikc.srt.sjson | 293 +++++++++++++++++++++ subs/NAlQWlfiB_Y.srt.sjson | 527 +++++++++++++++++++++++++++++++++++++ subs/T6jJuBoPtK4.srt.sjson | 260 ++++++++++++++++++ subs/UuML_lIpPVo.srt.sjson | 5 + subs/UwpSwe_RIbM.srt.sjson | 5 + subs/XgSOO1sfsa4.srt.sjson | 191 ++++++++++++++ subs/t24YP3JIKI8.srt.sjson | 86 ++++++ subs/wlcwr1VIQ7Y.srt.sjson | 422 +++++++++++++++++++++++++++++ 12 files changed, 2001 insertions(+) create mode 100644 subs/27GsG_REo_w.srt.sjson create mode 100644 subs/38euKuG1cUs.srt.sjson create mode 100644 subs/3g8ZeZlpv8E.srt.sjson create mode 100644 subs/3nCyei-6rtk.srt.sjson create mode 100644 subs/BUsj70M8ikc.srt.sjson create mode 100644 subs/NAlQWlfiB_Y.srt.sjson create mode 100644 subs/T6jJuBoPtK4.srt.sjson create mode 100644 subs/UuML_lIpPVo.srt.sjson create mode 100644 subs/UwpSwe_RIbM.srt.sjson create mode 100644 subs/XgSOO1sfsa4.srt.sjson create mode 100644 subs/t24YP3JIKI8.srt.sjson create mode 100644 subs/wlcwr1VIQ7Y.srt.sjson diff --git a/subs/27GsG_REo_w.srt.sjson b/subs/27GsG_REo_w.srt.sjson new file mode 100644 index 0000000000..bc505bb0d1 --- /dev/null +++ b/subs/27GsG_REo_w.srt.sjson @@ -0,0 +1,5 @@ +{ + "start": [], + "end": [], + "text": [] +} \ No newline at end of file diff --git a/subs/38euKuG1cUs.srt.sjson b/subs/38euKuG1cUs.srt.sjson new file mode 100644 index 0000000000..bc505bb0d1 --- /dev/null +++ b/subs/38euKuG1cUs.srt.sjson @@ -0,0 +1,5 @@ +{ + "start": [], + "end": [], + "text": [] +} \ No newline at end of file diff --git a/subs/3g8ZeZlpv8E.srt.sjson b/subs/3g8ZeZlpv8E.srt.sjson new file mode 100644 index 0000000000..881fbe6b2e --- /dev/null +++ b/subs/3g8ZeZlpv8E.srt.sjson @@ -0,0 +1,62 @@ +{ + "start": [ + 0, + 610, + 6120, + 8860, + 9590, + 10640, + 12310, + 16329, + 22030, + 24350, + 25440, + 29110, + 31860, + 32910, + 35920, + 38720, + 41110, + 42210 + ], + "end": [ + 610, + 6120, + 8860, + 9590, + 10640, + 12310, + 16329, + 22030, + 24350, + 25440, + 29110, + 31860, + 32910, + 35920, + 38720, + 41110, + 42210, + 44680 + ], + "text": [ + "SPEAKER 1: All right.", + "So v1 here is simply the difference between v0 and e1.", + "So v1 is simply v0 minus e1.", + "That's it.", + "What about i1?", + "That is pretty simple, too.", + "i1 is simply v1 divide by r1.", + "And because v1 is v0 minus e1, I can replace v1 by v0 minus", + "e1 and divide by r1.", + "That gives me i1.", + "So in this manner, I can go ahead and find all the vi's", + "and ii's very straightforwardly from the", + "known voltages.", + "So most often when we analyze circuits, we just go ahead and", + "find the e's-- the known voltages--", + "because we know we can very quickly find all the branch", + "voltages and currents.", + "And so, we often stop at the known voltage step." + ] +} \ No newline at end of file diff --git a/subs/3nCyei-6rtk.srt.sjson b/subs/3nCyei-6rtk.srt.sjson new file mode 100644 index 0000000000..cffcf0c06e --- /dev/null +++ b/subs/3nCyei-6rtk.srt.sjson @@ -0,0 +1,140 @@ +{ + "start": [ + 0, + 1810, + 4390, + 5000, + 8160, + 11910, + 14190, + 16580, + 17710, + 20290, + 23290, + 27270, + 30520, + 33040, + 33770, + 37220, + 39210, + 42270, + 48580, + 49500, + 53150, + 55790, + 58570, + 60780, + 63940, + 65360, + 67640, + 70590, + 74780, + 75890, + 78080, + 81440, + 84810, + 86530, + 89720, + 92150, + 93670, + 97330, + 100840, + 101940, + 104380, + 106730, + 110470, + 112880 + ], + "end": [ + 1810, + 4390, + 5000, + 8160, + 11910, + 14190, + 16580, + 17710, + 20290, + 23290, + 27270, + 30520, + 33040, + 33770, + 37220, + 39210, + 42270, + 48580, + 49500, + 53150, + 55790, + 58570, + 60780, + 63940, + 65360, + 67640, + 70590, + 74780, + 75890, + 78080, + 81440, + 84810, + 86530, + 89720, + 92150, + 93670, + 97330, + 100840, + 101940, + 104380, + 106730, + 110470, + 112880, + 115690 + ], + "text": [ + "SPEAKER 1: Well, it turns out that I don't need a variable", + "there because of the trick that I used in picking my", + "ground node.", + "By picking my ground node where it was, notice that the", + "voltage at this node is simply v0, because this node is", + "connected to ground by a voltage source.", + "And so the voltage source would hold the voltage of that", + "node at v0.", + "So I directly have the voltage of that node.", + "So right there I've done my second step.", + "So that's my step two of node analysis.", + "So let's move on and start off with step", + "three of node analysis.", + "All right?", + "Step three would be to write KCL for the nodes-- on each of", + "the nodes-- e1 and e2 here, which are my unknowns.", + "I'm going to write KCL for these nodes, and I am going to", + "substitute device laws and KVL in dividing the current that", + "leaves those nodes.", + "But also remember that as I work with currents, and sum", + "the currents for KCL, I'll simply use my usual", + "convention, which is sum the currents leaving a node always", + "so I don't make mistakes.", + "Now again, for another piece of convenience, I'm going to", + "use conductances.", + "So the variable I have is resistance.", + "1 by that resistance is the conductance, since I would", + "just use that to make my algebra a little simpler.", + "So let's get started.", + "Let's start with node e1.", + "And I'm going to write KCL at node e1.", + "Now, with KCL, notice that I'm going to follow my usual", + "convention to avoid mistakes.", + "I'm going to add up the currents that leave a node so", + "that I don't make mistakes.", + "So let's go ahead and start.", + "Let me start with KCL at e1.", + "So if you look at e1, what is the current that is going up", + "in that direction?", + "I know the node voltage here is e1.", + "I know the voltage of this node is v0.", + "So can you tell me what the current is going up?", + "Let me pause for a second so that you can think about it.", + "And then I'll go back and do it for you." + ] +} \ No newline at end of file diff --git a/subs/BUsj70M8ikc.srt.sjson b/subs/BUsj70M8ikc.srt.sjson new file mode 100644 index 0000000000..2c50e2fe77 --- /dev/null +++ b/subs/BUsj70M8ikc.srt.sjson @@ -0,0 +1,293 @@ +{ + "start": [ + 0, + 2770, + 5930, + 8290, + 9100, + 13450, + 15570, + 18030, + 21130, + 22730, + 25740, + 28500, + 30270, + 31450, + 33700, + 34860, + 38490, + 42530, + 43650, + 47650, + 49550, + 51890, + 53520, + 56710, + 60300, + 64280, + 66200, + 67460, + 69160, + 70590, + 73900, + 75410, + 78800, + 81960, + 84220, + 86470, + 89960, + 92320, + 94760, + 96580, + 97580, + 100560, + 102230, + 105870, + 107190, + 110660, + 113800, + 115400, + 118670, + 120630, + 122320, + 123450, + 125820, + 126700, + 129440, + 132530, + 134120, + 136770, + 139390, + 143590, + 145640, + 147150, + 149650, + 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177680, + 181560, + 185390, + 187320, + 189050, + 190410, + 193040, + 196630, + 197370, + 198540, + 200630, + 202200, + 206620, + 210430, + 211480, + 215010, + 216520, + 221520, + 223950, + 227650, + 229890, + 230760, + 232670, + 233920 + ], + "text": [ + "SPEAKER 1: Our third method is going to be the node method.", + "This method is going to be the most important method that we", + "learn, and you can apply it to all the circuits that you're", + "going to see.", + "This method is going to be a very specific application of", + "the KVL/KCL method.", + "This method has five steps.", + "The first step would be you go and select a reference node--", + "we call that a ground node--", + "represented by an inverted T symbol.", + "And you're going to measure all our voltages with", + "reference to this ground node.", + "The second step.", + "We label all the voltages of the remaining nodes with", + "respect to ground.", + "And these will be our primary unknowns.", + "As a third step, we will write KCL for all the nodes, leading", + "out the ground node.", + "And while writing KCL, we will apply a cool trick.", + "So KCL involves currents.", + "But notice that your primary variables", + "are your node voltages.", + "But KCL involves current, so what we will do is in step", + "three, we will derive the current, in terms of the node", + "voltages, and directly apply the element relationship", + "without actually having to write down", + "any specific current.", + "Then we go and solve for the node", + "voltages as our step four.", + "And finally, we go and back solve for the branch voltages", + "and branch currents.", + "Notice that for circuit analysis, our goal is to find", + "branch voltages and currents, and so to the extent that you", + "need to know all the branch voltages and currents, you can", + "go ahead and find them.", + "The node analysis method is the workhorse of our industry", + "and the workhorse of 6.002x.", + "And so you will be using it all over the place.", + "It's a very, very important method.", + "Let's get started.", + "And for this method, I'm going to use our", + "old faithful circuit.", + "For fun, I'm going to add a extra current source, I1, to", + "our circuit.", + "Notice that we now have seven elements in the circuit.", + "And with seven elements, the number of equations is going", + "to be completely unwieldy.", + "And so you will notice that with the node method, you will", + "be amazed that at the end, we will have to", + "solve only two equations.", + "Watch and see.", + "So as the first step of the node method, I have to select", + "the ground node.", + "Now, in general, you can select any node as the ground,", + "because voltages are always measured with", + "respect to a point.", + "There are differences in potentials between a pair of", + "points, so you can select any node as the ground.", + "But in general, to simplify our lives, I'd recommend using", + "a couple of rules to pick a ground node to", + "simplify the analysis.", + "The first thing to do is to find a node which has the", + "largest number of edges coming to it.", + "And in our circuit here, this node here, which connects R to", + "R5, and the current and voltage sources has the", + "largest number of edges.", + "So that seemed like a good candidate.", + "A second thing you can look at is look for a node that has", + "many of the sources connected to it.", + "And in this case, it does happen that the same node has", + "the voltage source also connected", + "to it with one terminal.", + "So let me go ahead and pick that as my ground node.", + "So let me go ahead and mark that as my ground node.", + "This will be my ground, and I mark it", + "with my ground terminal.", + "So this is step one.", + "Now, let's apply step two.", + "Step two will be label node voltages with respect to the", + "ground node.", + "So what are my nodes?", + "So I have a node here.", + "That's one node.", + "Let me label the node voltage with respect to ground as E1.", + "So if I take this as my ground voltage and", + "take that as a zero--", + "so the voltage at this node here is going to be E1 with", + "respect to the ground.", + "Let me pick this node here as E2 with respect to ground.", + "Finally, I have a third node here.", + "And what can you say about the voltage at that node?", + "Let me pause for a second while you think about it, and", + "then I will continue.", + "So what do you think the voltage is at that node?", + "Do I need a variable there?" + ] +} \ No newline at end of file diff --git a/subs/NAlQWlfiB_Y.srt.sjson b/subs/NAlQWlfiB_Y.srt.sjson new file mode 100644 index 0000000000..fe174cbd90 --- /dev/null +++ b/subs/NAlQWlfiB_Y.srt.sjson @@ -0,0 +1,527 @@ +{ + "start": [ + 480, + 3370, + 5480, + 9000, + 12620, + 16290, + 18680, + 22130, + 23780, + 29080, + 33400, + 34820, + 37230, + 41160, + 43480, + 48850, + 49960, + 53760, + 56670, + 57790, + 61270, + 66320, + 67390, + 71110, + 71930, + 73370, + 74830, + 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452740, + 455760, + 458590, + 463240, + 466350, + 467810, + 471440, + 473110, + 475010, + 477010, + 478630, + 479800, + 486380, + 488620, + 491370, + 493610 + ], + "text": [ + "SPEAKER 1: All right, let's begin by building a tool chest", + "of our analysis techniques.", + "But before we begin, it would worth while asking the", + "question, what does it mean to analyze a circuit?", + "Well analyzing a circuit simply means find all the", + "element v's and i's.", + "In other words, find all the branch variables.", + "And so what are these branch variables?", + "Well if you look at element R1, I can write its branch", + "variables as plus minus v1 here, so the", + "voltage across R1.", + "And I can assign a current i.", + "And for R4, as an example, I can say there's", + "v4 and there's i4.", + "And in general I'm pretty free to assign voltage and currents", + "in any direction.", + "But you will notice that I'm going to follow a discipline", + "where I'm going to draw the current entering into the", + "positive terminal.", + "And I will show you why in a quick second.", + "So as another example, I can define the element value for v", + "for the voltage source.", + "The branch variables here would be v0 and a current i0", + "going here.", + "And so on and so forth and I can do the", + "same for all the elements.", + "So analyzing a circuit really means go find all the element", + "v's and i's for the circuit.", + "Now we're ready to start with our analysis techniques that", + "will go into our tool chest. The first method that we will", + "look at is called a very basic KVL, KCL", + "method of circuit analysis.", + "And as I mentioned earlier, our goal with circuit analysis", + "is to find all the element v's and i's.", + "The KVL, KCL method is extremely simple.", + "In the first step in this method, you take your circuit", + "and you write down for each element their v-i", + "relationships.", + "Then, the second step, you pick all the nodes and for", + "each node you write KCL.", + "Then as a third step, you go through the loops one by one", + "and you write KVL for each of the nodes.", + "Notice that each of these equations is a very simple", + "equation containing simple algebraic expressions of the", + "currents and the voltages.", + "Now you'll end up with lots and lots of equations and you", + "will have lots of fun solving them.", + "Let's take a look at an example.", + "So our goal, as I said earlier, was to find all", + "elements v's and i's.", + "Now before we go in and do an example of using the KVL, KCL", + "method, I want to spend 30 seconds telling you about a", + "couple of ideas on how to label element v's and i's.", + "So for example, here's an element, the", + "Element e in some circuit.", + "And notice it has a v and an i.", + "In general, what we're going to do is we are going to", + "follow a little discipline or a little convention in how we", + "assign the voltage and currents.", + "Specifically, we are going to take the current to be", + "positive going into the positive voltage terminal", + "So in this case, here is the positive voltage terminal of", + "the Element e.", + "And so we're going to be assigning currents to be going", + "into the positive voltage terminal.", + "Now you can do whatever you want, it", + "really doesn't matter.", + "You can go and assign currents and voltages any which way and", + "reverse them and KVL, KCL will simply work.", + "It just turns out that in a lot of what we do in circuits", + "and electronics, it is useful to follow conventions so that", + "you don't make silly algebraic mistakes.", + "So whenever you have a choice of being able to do something", + "10 different ways, it is just good to be disciplined and use", + "one technique all the time so that you", + "just don't make mistakes.", + "Now one benefit of taking the current to be going into the", + "positive terminal of the element is that the power", + "consumed by the element, which is given by vi, is positive.", + "So if you choose your convention of the current", + "going into the positive terminal, then the power", + "consumed by the element, vi, is going to be positive.", + "So this way, or this convention, of assigning", + "voltage and currents as the branch variables is called the", + "associated variables discipline.", + "And again, as with all disciplines, it's something we", + "impose on ourselves, it's a convention.", + "We just follow this convention to simplify our lives and to", + "reduce the chance that we're going to make mistakes.", + "And if you don't like this, don't worry, go ahead, make my", + "day, pick different convention for v and i, just be careful.", + "If you follow this convention, it is less likely you will", + "make mistakes.", + "Now before we actually begin the KVL method, there is one", + "more thing that I need to quickly cover which is a few", + "elements relationships.", + "So you have seen resistors before.", + "So for a resistor with the resistance value R, the v-i", + "relationship is simply given by v equals iR.", + "Where if this is my voltage v, and the", + "current i, v equals iR.", + "Next, for our voltage source, let me draw out a voltage", + "source with voltage V0 in this case.", + "And let me assign branch variable, v plus v and v, and", + "the current i.", + "Then the element relationship, v is given by V0.", + "One of the places where I find students getting confused is", + "the difference between element values and the", + "component value itself.", + "So if you look at a voltage source of this sort, V0 is a", + "property or this voltage source.", + "So if it's a battery, it might supply a", + "voltage V0 of 1.5 volts.", + "However, when I take this voltage source and I put that", + "into a circuit, with the circuit it's going to draw", + "some current i and there will be some voltage across it.", + "If there's a resistor, it will be some of the voltage.", + "But if I put an ideal voltage source with internal voltage", + "V0 and I stick that into a circuit, then the branch", + "variable v associated with that will also be equal to V0.", + "But in general, that doesn't have to be true.", + "Next, let me go to a current source.", + "In this case, I would define my current source like so.", + "I can also apply branch variables v and i.", + "And the equation, if the current source supplies a", + "current I0, then the element relationship for this is given", + "by i equals I0.", + "So these are three examples of element relationships for", + "resistors, voltage sources, and current sources.", + "OK, we are done with the preamble.", + "We are now all set to dive into method one of circuit", + "analysis, the KVL, KCL method.", + "So let's apply this method to the demo circuit", + "that we used earlier.", + "And let's see how we can find out all the", + "element v's and i's.", + "Now recall, the KVL, KCL method said, in fact circuit", + "analysis said, that solving a circuit involves finding all", + "the element v's and i's.", + "So why don't we start this example with labeling all the", + "v's and i's for our demo circuit.", + "OK, so let's get started and very quickly label all the", + "branch variables.", + "And I'm going to to follow the associated variable discipline", + "in doing that.", + "So let me start by labelling all the branch variables.", + "Let me call this v0, current is i0 coming in here.", + "Let me call this v1 and let me say this is current i1.", + "Let me say this is v4, current i4.", + "Let me say this is v3 and current i3.", + "Let me then say that this guy here is v5 and current is i5.", + "In this case, it's v2 and the current is i2.", + "So I have a bunch of branch variables assigned.", + "And I also have these branch variables involved with the", + "currents and voltages.", + "And notice here that in this example I have used the", + "associated variable discipline, that I have", + "assigned all my currents flowing into the positive", + "terminal of each of the assigned branch voltages.", + "So here I get 12 unknowns in all.", + "If we count v0, v1, v2, v3, v4, and v5, that's 6.", + "And i0 through i5, that's another 6, so I have a total", + "of 12 unknowns.", + "Also notice that is a is a node, b is a node, c is a", + "node, and d is a node.", + "And so those are my nodes.", + "I will be writing KCL for those nodes.", + "And then I have a bunch of loops.", + "So what are my loops here?", + "So I have a loop L1, I have a loop L2, I have a loop L3.", + "Now I claim there is one more loop.", + "Like let me pause here for a second and have you think", + "about where that fourth loop is." + ] +} \ No newline at end of file diff --git a/subs/T6jJuBoPtK4.srt.sjson b/subs/T6jJuBoPtK4.srt.sjson new file mode 100644 index 0000000000..5114ef81c4 --- /dev/null +++ b/subs/T6jJuBoPtK4.srt.sjson @@ -0,0 +1,260 @@ +{ + "start": [ + 320, + 4820, + 6840, + 9100, + 10110, + 15230, + 17310, + 21890, + 24700, + 31260, + 35190, + 37900, + 39250, + 42630, + 47040, + 49210, + 49810, + 52180, + 55380, + 57000, + 58760, + 60610, + 63910, + 68520, + 70220, + 73780, + 75760, + 81070, + 85540, + 87860, + 93830, + 97170, + 99230, + 100240, + 102810, + 103740, + 107310, + 108200, + 110340, + 115060, + 115916, + 119090, + 121720, + 125850, + 128570, + 132100, + 135865, + 138510, + 140960, + 145040, + 145890, + 149280, + 155300, + 156500, + 159910, + 164370, + 165700, + 168960, + 169540, + 172280, + 172970, + 177850, + 180800, + 182460, + 184780, + 186070, + 188430, + 190890, + 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"SPEAKER 1: All right, so to do KCL at e2, let's start with", + "the current leaving this node.", + "Remember, my usual habit is to sum the", + "nodes leaving the node.", + "So the current heading in this direction will be e2 minus e1", + "divided by R3.", + "So current going left from that node will be e2 minus e1", + "divided by R3 or multiplied by G3.", + "Then the current going up will be e2 minus V0 times G4.", + "And the current leaving the node and going down", + "will be e2 times G5.", + "Have I missed anything?", + "Aha, there is a current here that's coming into the node.", + "And so therefore, the current leaving the mode is minus I1.", + "And all of that sums up to zero.", + "There you have it.", + "So I've written KCL for the two nodes.", + "And I've substituted the device laws as I've been", + "writing it so I don't have this", + "intermediate current variable.", + "So just stare at the beauty of this.", + "Notice that I have two equations, one and two, and I", + "have two variables, e1 and e2, two unknowns and two equations", + "and that's it.", + "OK, so let me go on to step four of the node method.", + "The step four of the node method is simply to go ahead", + "and solve for the node voltages, e1 and e2.", + "So I have my two equations which reflect the KCL at node", + "e1 and KCL at e2.", + "So now it's simply juggling it on with some math and trying", + "to collect all the coefficients of e1 and those", + "of e2, collect them all and just write", + "them a little cleanly.", + "So let me move all the constant terms to the", + "right-hand side.", + "And I will move the variables, or the unknowns, to the", + "left-hand hand side.", + "So let me start with e1.", + "So notice that e1, I multiplied by G1, so", + "I write that down.", + "Multiply by G3, so I write that down.", + "And multiply by G2, so I write that down too.", + "So I get e1 times G1 plus G3 plus G2.", + "And then I collect the terms in e2.", + "And there's only one here, which is minus G3.", + "And the constant terms are here, V0 G1.", + "And I'm going to move that to the right-hand side and write", + "that down as V0 G1.", + "For the next set of steps, I go ahead and do e1 for the", + "next equation.", + "I get minus G3.", + "And then for e2, I go ahead and get a G5, and I get a G4,", + "and I get a G3.", + "So it's G3, G4, and a G5.", + "And I can move the constant terms, which is V0 G4, and I", + "want the right-hand side.", + "And in this case, they both become positive as they move", + "to the right.", + "And I get a I1 here.", + "Good, there you go.", + "So I end up with two equations and two unknowns.", + "And notice I have by e1 times something plus e2 times", + "something equals a constant.", + "And then again, that e1 times something plus e2 times", + "something is another constant.", + "So I two equations and two unknowns.", + "And see how remarkably simple this is.", + "This is basic high school math to solve a pair of", + "simultaneous equations in order to get the answer.", + "And just to be a complete here, let me go ahead and", + "complete it for you.", + "So supposing in step four number four you've gone and", + "solved for the node method, and by solving the node method", + "you get the values of e1 and e2.", + "So let's say you've gone and solved the simultaneous", + "equations for step four and you have e1 and e2.", + "Then, to complete your circuit analysis you need to find the", + "branch voltages.", + "And so you can go ahead and find all the v-i's and i-i's.", + "So in this case, one of my branch voltages is v1 i1.", + "So I just do a couple of quick examples just to show you that", + "it's pretty simple.", + "So what is v1 here?", + "Well let me pause and have you do it." + ] +} \ No newline at end of file diff --git a/subs/UuML_lIpPVo.srt.sjson b/subs/UuML_lIpPVo.srt.sjson new file mode 100644 index 0000000000..bc505bb0d1 --- /dev/null +++ b/subs/UuML_lIpPVo.srt.sjson @@ -0,0 +1,5 @@ +{ + "start": [], + "end": [], + "text": [] +} \ No newline at end of file diff --git a/subs/UwpSwe_RIbM.srt.sjson b/subs/UwpSwe_RIbM.srt.sjson new file mode 100644 index 0000000000..bc505bb0d1 --- /dev/null +++ b/subs/UwpSwe_RIbM.srt.sjson @@ -0,0 +1,5 @@ +{ + "start": [], + "end": [], + "text": [] +} \ No newline at end of file diff --git a/subs/XgSOO1sfsa4.srt.sjson b/subs/XgSOO1sfsa4.srt.sjson new file mode 100644 index 0000000000..5043d89bcf --- /dev/null +++ b/subs/XgSOO1sfsa4.srt.sjson @@ -0,0 +1,191 @@ +{ + "start": [ + 0, + 3460, + 4680, + 6760, + 9350, + 12310, + 14480, + 18090, + 20390, + 22260, + 26930, + 30960, + 35530, + 38130, + 41330, + 44645, + 50050, + 51500, + 54070, + 57830, + 63480, + 67540, + 70730, + 75790, + 81690, + 84950, + 88155, + 92915, + 94960, + 99820, + 103150, + 106810, + 110690, + 112890, + 116300, + 119110, + 121720, + 123920, + 126460, + 127280, + 131240, + 132040, + 133890, + 136430, + 139960, + 144400, + 149070, + 154810, + 157330, + 161090, + 164460, + 170610, + 174440, + 176550, + 180080, + 184000, + 186310, + 189590, + 192860, + 196370, + 199210 + ], + "end": [ + 3460, + 4680, + 6760, + 9350, + 12310, + 14480, + 18090, + 20390, + 22260, + 26930, + 30960, + 35530, + 38130, + 41330, + 44645, + 50050, + 51500, + 54070, + 57830, + 63480, + 67540, + 70730, + 75790, + 81690, + 84950, + 88155, + 92915, + 94960, + 99820, + 103150, + 106810, + 110690, + 112890, + 116300, + 119110, + 121720, + 123920, + 126460, + 127280, + 131240, + 132040, + 133890, + 136430, + 139960, + 144400, + 149070, + 154810, + 157330, + 161090, + 164460, + 170610, + 174440, + 176550, + 180080, + 184000, + 186310, + 189590, + 192860, + 196370, + 199210, + 200460 + ], + "text": [ + "SPEAKER 1: OK, let's now work on the second method of", + "circuit analysis.", + "This is actually a very simple method.", + "And oftentimes when you're applying some of the more", + "sophisticated methods, it is helpful to apply these methods", + "as some of the partial steps.", + "You can find more about this method and the KVL KCL method", + "in chapter two of the textbook.", + "So this method is very simple.", + "If you have a set of resistors in series, R1 through RN, then", + "you can write up an equivalent resistor whose resistance is", + "equal to the sum of the individual resistances.", + "Now you can also do a complimentary circuit.", + "You can make a set of conductances.", + "Notice that G is our nomenclature for conductance.", + "So G1, for example, is 1 divided by R1 and so on, so", + "G's a conductance.", + "So when I have a set of conductances in parallel, then", + "I can add them all up and replace them with a resulting", + "conductance given by G1 plus G2 plus G3 dot dot dot GN,", + "where G1 equals 1 by RI is a conductance.", + "Another simple thing to remember is when you have two", + "resistances in parallel, let's say R1 and R2, the equivalent", + "resistance is given by R1 R2 divide by R1 plus R2.", + "This is just a special case for two resistors.", + "Let's continue one with element combinations rules.", + "In case C is when I have two voltage sources in parallel.", + "Let's call them V1 and V2.", + "Then I can replace them with a single voltage source whose", + "voltage is given by V1 plus V2.", + "I can get the current based circuit in a similar manner.", + "So let's say I have two current sources in parallel,", + "I1 in parallel with I2.", + "Then I can replace them with a single current source whose", + "current is I1 plus I2.", + "In this example, I would like to use element combination", + "rules to solve for the following situation.", + "So I have a little circuit here with a voltage source of", + "three resistors.", + "And let's say I care about finding the current I through", + "that branch.", + "So how do I go about doing it?", + "So let's start applying element competition rules.", + "As a first step, let me combine these two resistances.", + "And so I get the same voltage source, my resistance R1 here.", + "But in place of R2 and R3, I get the combination of", + "resistors given by R2 R3 3 divide by R2 plus R3.", + "Now as soon as I get that, I now have two resistances in", + "series, so I can sum them up very quickly like so.", + "And I can get a single resistance here, R, which is", + "the sum of R1 plus R2 R3 divide by R2 plus R3.", + "So now notice that this was my current that I needed to find.", + "And I was the current I needed to find.", + "So I brought this down to a very simple pattern.", + "And so I can very quickly write I is simply given by V", + "divided by R.", + "Now the textbook in this particular section gives you a", + "lot more interesting examples of how you can use intuitive", + "analysis to analyze many, many circuits like this.", + "And I would encourage you to go and read that section", + "that's part of section two." + ] +} \ No newline at end of file diff --git a/subs/t24YP3JIKI8.srt.sjson b/subs/t24YP3JIKI8.srt.sjson new file mode 100644 index 0000000000..ed29622137 --- /dev/null +++ b/subs/t24YP3JIKI8.srt.sjson @@ -0,0 +1,86 @@ +{ + "start": [ + 290, + 830, + 4140, + 6550, + 7710, + 10620, + 11890, + 16340, + 19580, + 23230, + 25530, + 27800, + 28160, + 28780, + 32250, + 35850, + 39250, + 40590, + 44190, + 48230, + 50950, + 53700, + 54240, + 58410, + 61390, + 63910 + ], + "end": [ + 830, + 4140, + 6550, + 7710, + 10620, + 11890, + 16340, + 19580, + 23230, + 25530, + 27800, + 28160, + 28780, + 32250, + 35850, + 39250, + 40590, + 44190, + 48230, + 50950, + 53700, + 54240, + 58410, + 61390, + 63910, + 66290 + ], + "text": [ + "SPEAKER 1: All right.", + "So I can apply the KVL rule.", + "The KVL rule simply says that I can take the difference in", + "the node voltages.", + "And then applying the element rule, I can divide by R1 to", + "get the current going up.", + "So the current going up is simply E1 minus V0, which is", + "the voltage difference between these two points.", + "And I can divide that by R1 to get the current going up.", + "And dividing by R1 is the same as multiplying by the", + "conductance, G1.", + "OK.", + "Next.", + "What is the current going in this direction?", + "The current going in that direction is simply E1 minus", + "E3 divided by R3, or multiplied by the", + "conductance, G3.", + "And finally, I can figure out the current going down, which", + "is simply E1 minus 0, which is the ground", + "potential, times G2.", + "And that sums to 0 by KCL.", + "OK.", + "Next let me write down KCL at the node two.", + "So let me give you some practice, and let me pause", + "while you think about doing it yourself.", + "And then I'll go ahead and do it." + ] +} \ No newline at end of file diff --git a/subs/wlcwr1VIQ7Y.srt.sjson b/subs/wlcwr1VIQ7Y.srt.sjson new file mode 100644 index 0000000000..5206cd416f --- /dev/null +++ b/subs/wlcwr1VIQ7Y.srt.sjson @@ -0,0 +1,422 @@ +{ + "start": [ + 250, + 4310, + 6240, + 7610, + 11120, + 12830, + 15980, + 18220, + 20770, + 23710, + 27110, + 28320, + 31150, + 34250, + 36250, + 40670, + 43060, + 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+ 334910, + 338530, + 340440, + 344585, + 345700, + 347750, + 350080, + 353520, + 356025, + 359990, + 363370, + 366270, + 369300, + 370690, + 374130, + 375570, + 378240, + 380200, + 383470 + ], + "end": [ + 4310, + 6240, + 7610, + 11120, + 12830, + 15980, + 18220, + 20770, + 23710, + 27110, + 28320, + 31150, + 34250, + 36250, + 40670, + 43060, + 44530, + 49040, + 51560, + 56130, + 59000, + 60130, + 64519, + 67280, + 73230, + 76100, + 78905, + 81230, + 83840, + 87660, + 91495, + 95020, + 97830, + 100230, + 103160, + 106980, + 108970, + 111320, + 113640, + 114490, + 117130, + 119560, + 121640, + 123220, + 126660, + 129860, + 135490, + 139050, + 142580, + 144355, + 145520, + 150010, + 153280, + 154240, + 156190, + 162220, + 165540, + 168010, + 170820, + 176620, + 178940, + 182510, + 185120, + 186480, + 190160, + 194290, + 197430, + 200070, + 203330, + 205930, + 208550, + 214080, + 217300, + 217940, + 221700, + 225215, + 228900, + 230690, + 233510, + 236260, + 239890, + 244060, + 245800, + 247680, + 248520, + 251730, + 252870, + 255210, + 257060, + 258610, + 259970, + 261980, + 263460, + 264960, + 265690, + 267360, + 269270, + 272860, + 277250, + 279590, + 282410, + 285280, + 288140, + 289090, + 292500, + 296050, + 297910, + 304180, + 309050, + 310280, + 313280, + 317240, + 319240, + 320990, + 323790, + 324380, + 327770, + 330880, + 334910, + 338530, + 340440, + 344585, + 345700, + 347750, + 350080, + 353520, + 356025, + 359990, + 363370, + 366270, + 369300, + 370690, + 374130, + 375570, + 378240, + 380200, + 383470, + 384720 + ], + "text": [ + "SPEAKER 1: So the fourth loop really is this outer loop here", + "that goes like so.", + "That is four.", + "So notice that I have four nodes, and I have four loops,", + "and I have 12 unknowns.", + "And the goal of the method will be to find out the values", + "of each of these 12 unknowns.", + "If you're ready, now that you've labeled the circuit,", + "let's go to step one of the KVL, KCL method.", + "And our overall goal will be to find out the values of", + "these 12 unknowns.", + "You see the circuit on the right-hand side, and then", + "notice that all the branch variables have been assigned", + "as we did in the previous step.", + "So the first step of the KVL, KCL method is to write down", + "all the element v, i relationships so", + "there are six elements--", + "one, two, the R2, R3, R4, R5, so six elements.", + "So let's write down six v, i relationships.", + "So for the volted source, I get V0 is capital V0.", + "And this is given because I know the value", + "of the voltage here.", + "I can do V1 is i1R1.", + "V2 is i2R2.", + "And then for resistor three, I can write V3 is i3R3.", + "V4 is i4R4.", + "And V5 is i5R5.", + "So notice that there are six equations here.", + "So we're done with the element relationships.", + "And let me now go on to the next step of the KVL, KCL", + "method, which is to write KCL at each of the nodes.", + "So I have four nodes, A, B, C, and D. So let's start by", + "writing KCL for node eight.", + "So let's write KCL for node eight.", + "So at node eight, notice that I have three currents deal", + "with, i0, i1, and i4.", + "So here, again, I'm going to use a little bit of a", + "convention in how I sum up currents.", + "And as a rule, I can sum currents going in or", + "currents going out.", + "But again, I'm just going to use a convention.", + "I am going to sum currents leaving the node.", + "So for every node, I'm just going to sum currents leaving", + "the node if they should add up to 0.", + "So for node eight, notice that current i0 is leaving the", + "node, i1 is leaving the node, and i4 is leaving the node.", + "So I can sum them all up to be i0 plus i4 plus i1 equals 0.", + "Similarly, for node b, I have currents--", + "let's see, we have i2 leaving the node, so i2.", + "Then we have i3 leaving the node.", + "So I write i3.", + "And then, notice that i1 is coming into the node.", + "So there, it's not a plus, but it's a minus i1", + "coming into the node.", + "And that equals 0.", + "Then, similarly, at the next node, b, I can write down i5", + "leaving the node minus i4 leaving the node.", + "And then I have i3 coming into the node.", + "So it is minus i3 leaving the node.", + "Finally, for c, I have minus i0 minus i2 minus i5 equals 0.", + "So in this case, I have four equations.", + "But notice that even though there's four equations,", + "because of the circuit topology, there is one", + "dependent equation.", + "So I really end up getting three independent equations.", + "So as you're doing the analysis, you will find that", + "there's only three independent equations, given these four", + "nodes in a circuit.", + "OK, let's go to step three of the KVL, KCL method.", + "And the step three says write down the Kirchhoff's Voltage", + "Law, KVL, for each of the nodes.", + "So here, again, let me start by writing KVL for loop one.", + "So what I'm going to do is I'm going to follow loop one in", + "this direction.", + "I'm going to go around clockwise for loop one.", + "So here, again, I have a convention to follow.", + "As I go down the loop, how do I write down the voltages?", + "There's many conventions people follow.", + "But the convention that I follow and I recommend, which", + "is very simple, is as you go around the loop, you simply", + "assign to each voltage the first encountered sign.", + "So as you go around this loop here, I get the v0 voltage.", + "And the sign encountered is minus.", + "So I'm going to assign that a minus sign.", + "So let's do that.", + "So for the loop one, I'm going to go around the", + "loop in this direction.", + "And the first encountered voltage is v0.", + "And the first encountered sign is a minus.", + "So I write minus v0.", + "And I continue down this way.", + "And I hit v1.", + "In this case, I hit the plus sign.", + "So it is plus v1.", + "And I go down.", + "And then I hit plus v2.", + "And that sums to 0.", + "Similarly, for loop two, I'm going to go around the loop.", + "Why don't I say just for fun, for this loop, why don't I go", + "around in a counterclockwise manner.", + "So in this case, I'm going to hit the positive terminal of", + "v1 first. So I write plus v1.", + "Then I'm going to hit the positive terminal of v3.", + "So I write plus v3.", + "Then the minus terminal of v4, so minus v4.", + "So similarly, for loop three, I get v3 plus v5", + "minus v2 equals 0.", + "And for loop four, I get minus v0 plus v4 plus v5 equals 0.", + "And again, because of the circuit topologies, there's", + "three independent loops.", + "And so I get three independent equations.", + "And so this last equation is redundant.", + "OK, so putting it all together, I'm in", + "the KVL, KCL method.", + "You saw that we developed six equations for the element", + "relationships.", + "And then we had three independent equations from the", + "KCL at the nodes and three more KVL at the nodes.", + "So in all, notice that we ended up with 12 equations.", + "And recall we had 12 unknowns, v0 through v5", + "and i0 through i5.", + "So now you can take these 12 equations and put them into a", + "hopper and turn the crank.", + "And you can go and get the answer.", + "However, this is very grubby.", + "But even a simple circuit like this, now, with just a small", + "number of elements, three inner loops and one outer", + "loop, I had a horrible mess, 12 equations, 12 unknown.", + "And so this works, but this is a real pain.", + "We will see that the node method, which builds on the", + "KVL, KCL method, will be much, much better", + "and will be way simpler.", + "And we'll have far fewer equations than", + "the KVL, KCL method.", + "But it's good to know about the KVL, KCL method, because", + "it's the simplest method that there is.", + "Just that it ends up with a whole boatload of equations", + "that you have to solve." + ] +} \ No newline at end of file