1 00:00:22,590 --> 00:00:25,590 Unknown: Okay, welcome to part three. In this one, we're going 2 00:00:25,590 --> 00:00:30,300 to still talk about AC voltage. And we're going to see how AC 3 00:00:30,300 --> 00:00:35,910 voltage interacts with a DC component. But before we get 4 00:00:35,910 --> 00:00:39,600 into the next slide, I just want to make sure that you understand 5 00:00:39,600 --> 00:00:42,900 something and you'll see why when we go to the next. Next 6 00:00:42,900 --> 00:00:49,890 slide. There's 360 degrees in a sine wave of as I show you here, 7 00:00:49,890 --> 00:00:56,670 we start out with zero.

The first positive peak is 90. It 8 00:00:56,670 --> 00:01:02,070 goes back through the zero line and that 180 degrees, the 9 00:01:02,070 --> 00:01:09,000 negative peak is at 270 degrees. And when we finish up the cycle, 10 00:01:09,000 --> 00:01:13,380 it's 360 to zero. And we start the whole thing all over again. 11 00:01:14,430 --> 00:01:19,500 Obviously, there's many points in between zero and 90, there's 12 00:01:19,530 --> 00:01:27,660 30 degrees and 45 degrees, and then 120 degrees and 130, and so 13 00:01:27,660 --> 00:01:32,280 forth. But the only thing I'm showing you is the, the main 14 00:01:32,280 --> 00:01:35,730 intersection points to make a point on the next on the next 15 00:01:35,730 --> 00:01:42,300 slide.

All right, so just hold on to that this 360 degrees in a 16 00:01:42,300 --> 00:01:45,000 sine wave. All right, let's erase that and go to the next 17 00:01:45,000 --> 00:01:48,180 slide. Okay, well, 18 00:01:48,180 --> 00:01:50,670 let's let's look at this slide here. 19 00:01:51,810 --> 00:01:52,380 And 20 00:01:53,070 --> 00:01:56,490 I've got a little chart down here where we start off at zero 21 00:01:56,490 --> 00:02:03,780 9181 73 six And then we start all over again. Alright, so 22 00:02:03,780 --> 00:02:16,920 those These are my intersection points, zero, 9182 7360 and 23 00:02:16,920 --> 00:02:21,360 zero. All right, so there they are.

If we look at my circuit 24 00:02:21,360 --> 00:02:25,110 over here, my little battery circuit here, I've got a battery 25 00:02:25,140 --> 00:02:30,060 10 volts and I've got an AC source right here. ac sources. 26 00:02:30,060 --> 00:02:35,100 10 volts peak to peak, meaning five volts above the zero line 27 00:02:35,100 --> 00:02:41,160 and five volts below the zero line. Alright, so, what are we 28 00:02:41,160 --> 00:02:45,390 trying to do here? Well, I'm what I'm trying to explain is 29 00:02:46,530 --> 00:02:53,280 how we get a AC waveform on a DC component. And we'll see that 30 00:02:53,280 --> 00:02:53,910 now.

31 00:02:55,199 --> 00:02:59,939 As I explain this, what we should see is a 32 00:03:01,079 --> 00:03:09,179 waveform writing on a 10 volt DC component with a 10 volt peak to 33 00:03:09,179 --> 00:03:14,399 peak AC waveform. So let's clear the slide and we're going to 34 00:03:14,399 --> 00:03:15,329 explain this. 35 00:03:18,210 --> 00:03:20,820 Okay, look at it here. Let's 36 00:03:21,120 --> 00:03:23,310 put my little meter 37 00:03:25,080 --> 00:03:31,200 or M four meter or some type of device that will monitor voltage 38 00:03:31,200 --> 00:03:36,150 like an oscilloscope. Alright, and we're gonna look here, and 39 00:03:36,150 --> 00:03:38,820 we're going to look here and we're going to, we're going to 40 00:03:38,820 --> 00:03:47,130 look at zero degrees. So we're going to look at VA, 41 00:03:47,760 --> 00:03:48,870 which is right here.

42 00:03:50,010 --> 00:03:55,200 And let's start that. So at zero degrees, VA is what? 43 00:03:55,890 --> 00:03:57,120 Plus 10 volts 44 00:03:59,370 --> 00:03:59,910 All right. 45 00:04:01,439 --> 00:04:06,449 Just at the sentient at zero degrees, we're coming down this 46 00:04:06,449 --> 00:04:14,909 way, going through my AC source. But what's my AC source at zero 47 00:04:14,939 --> 00:04:15,809 degrees 48 00:04:15,900 --> 00:04:17,280 at that instance? 49 00:04:17,669 --> 00:04:20,129 It's zero volts AC.

50 00:04:22,019 --> 00:04:27,929 So zero volts AC plus 10 volts is 51 00:04:28,560 --> 00:04:32,730 10 volts and there I am right here. All right. 52 00:04:34,140 --> 00:04:40,740 And if I take my media lead now, and and at that instant at zero 53 00:04:40,740 --> 00:04:43,530 degrees and put my media lead right here, 54 00:04:45,060 --> 00:04:47,250 VB is going to be zero volts 55 00:04:47,700 --> 00:04:52,860 and VC, which is my ground reference is always going to be 56 00:04:52,860 --> 00:05:03,270 zero volts. Okay, let's look here at at 90 degrees. And we're 57 00:05:03,270 --> 00:05:06,450 going to look right here, and right here at that instant. 58 00:05:07,380 --> 00:05:12,750 Let's get my meter up the let's look at VA. And again, we're 59 00:05:12,750 --> 00:05:17,520 going to make one complete revolution.

So if I start here, 60 00:05:19,289 --> 00:05:20,699 I get plus 61 00:05:22,290 --> 00:05:23,400 10 volts. 62 00:05:24,660 --> 00:05:29,760 Coming down through my AC source. What's VB? At that 63 00:05:29,790 --> 00:05:35,280 instant when it's 90 degrees, it's a positive five volts peak, 64 00:05:35,580 --> 00:05:36,570 AC 65 00:05:41,400 --> 00:05:42,000 plus, 66 00:05:43,350 --> 00:05:46,200 and then we're coming down to the 67 00:05:47,550 --> 00:05:48,750 inside of the meter. 68 00:05:50,340 --> 00:05:56,010 So 10 volts was five volts at that instant. 69 00:05:57,390 --> 00:05:59,100 What's VA gonna be?

70 00:06:00,930 --> 00:06:02,250 15 Volts. 71 00:06:03,090 --> 00:06:08,370 If I take my media lead and place it on VB at that instant, 72 00:06:08,790 --> 00:06:14,250 VB is going to be five volts peak right here. 73 00:06:18,300 --> 00:06:20,490 Okay, now we're looking at 180 74 00:06:21,600 --> 00:06:22,800 which is right here. 75 00:06:25,950 --> 00:06:28,080 Again, let's put my meter on there 76 00:06:30,150 --> 00:06:37,110 and one complete revolution. So again, I go through my battery 77 00:06:37,110 --> 00:06:44,220 which is plus 10 volts DC, go through my AC waveform, but at 78 00:06:44,250 --> 00:06:52,050 180 watts the value of my AC waveform is zero. So therefore 79 00:06:52,380 --> 00:07:01,560 10 plus zero is zero.

So VA is going to be 10 volts VB, if I 80 00:07:01,560 --> 00:07:06,630 take my media lead and go there is going to be zero volts at 81 00:07:06,720 --> 00:07:07,380 that 82 00:07:07,440 --> 00:07:09,150 instant of 180 83 00:07:10,170 --> 00:07:11,130 degrees. 84 00:07:14,549 --> 00:07:18,809 Okay, let's continue on with 270 degrees right there and there's 85 00:07:18,809 --> 00:07:26,039 my meter up here down there. And one complete revolution. Okay, 86 00:07:26,039 --> 00:07:30,929 so what do I see going this way still my 10 volts DC that 87 00:07:30,929 --> 00:07:41,459 doesn't change. But what is my AC source? It's a minus five 88 00:07:41,459 --> 00:07:49,919 volts peak.

It's going below the zero line right here. All right, 89 00:07:50,189 --> 00:07:51,809 so 10 volts, 90 00:07:53,520 --> 00:07:55,650 plus or minus five volts. 91 00:07:56,490 --> 00:07:59,460 VA is going to be a plus 92 00:07:59,460 --> 00:08:00,000 five volts. 93 00:08:01,020 --> 00:08:05,280 And if I take my media lead at that instance and go to VB, I'm 94 00:08:05,280 --> 00:08:07,860 going to see a minus five volts peak. 95 00:08:13,469 --> 00:08:18,419 Okay, now we're going to do 360 degrees, right there is my 96 00:08:18,419 --> 00:08:19,079 meter. 97 00:08:21,000 --> 00:08:22,650 Hey, we're right right here.

98 00:08:23,850 --> 00:08:26,220 And again, I go through my 99 00:08:26,220 --> 00:08:31,590 battery plus 10 volts down through my voltage source, but 100 00:08:31,590 --> 00:08:39,840 what's my voltage source at 360 degrees? zero volts AC, come 101 00:08:39,840 --> 00:08:44,640 down through so what am I going to measure what's va? Va is 102 00:08:44,640 --> 00:08:45,810 going to be 10 volts 103 00:08:46,590 --> 00:08:49,440 DC and VB is going to be zero. 104 00:08:50,160 --> 00:08:53,370 And then that just keeps repeating and repeating and 105 00:08:53,370 --> 00:08:54,030 repeating. 106 00:08:55,140 --> 00:08:57,060 Okay, now, I don't know if I 107 00:08:57,060 --> 00:08:58,680 stress this but I will now 108 00:08:58,890 --> 00:09:05,280 even though we are We pick these values here, what I call the 109 00:09:06,000 --> 00:09:11,010 well word intersect the zero line and the most positive peak 110 00:09:11,010 --> 00:09:15,360 and negative peak.

These are varying right here. So 111 00:09:17,220 --> 00:09:19,410 I mean, it's going to go for instance, 112 00:09:19,950 --> 00:09:29,220 right here, it's going to go from zero up to 15 volts, but 113 00:09:29,220 --> 00:09:32,040 there's going to be some varying voltage values in there. 114 00:09:32,549 --> 00:09:34,139 Okay? And I'm 115 00:09:34,140 --> 00:09:36,960 just showing you the main points, but we know that it's 116 00:09:36,960 --> 00:09:41,010 gonna, in what they say it's going to have a sinusoidal 117 00:09:41,010 --> 00:09:46,050 waveform or a sinusoidal shape going from zero up to the peak. 118 00:09:47,910 --> 00:09:48,330 Alright, 119 00:09:49,049 --> 00:09:51,509 so that's it. So let's, let's look at another one.

120 00:09:56,070 --> 00:09:58,950 Okay, well let's let's look at this one. Now we've changed 121 00:09:59,250 --> 00:10:04,140 something here. I still got 10 volts DC but look at going from 122 00:10:04,140 --> 00:10:08,580 10 volts peak to peak 220 volts peak to peak. So let's see what 123 00:10:08,580 --> 00:10:12,180 happens. Let's see what might change here. 124 00:10:13,289 --> 00:10:14,099 And 125 00:10:16,559 --> 00:10:20,579 what started zero.

I'm going to go a little quicker here because 126 00:10:20,849 --> 00:10:25,769 you've got that so here's my meter. I right there right 127 00:10:25,769 --> 00:10:34,979 there, VA. Okay, VA is going to be 10 volts, because VB is zero 128 00:10:34,979 --> 00:10:39,119 volts. So we know that VA is going to be 10 volts and here it 129 00:10:39,119 --> 00:10:40,169 is right there. 130 00:10:41,880 --> 00:10:44,490 Okay, now we're going to 90 131 00:10:45,720 --> 00:10:46,830 and let's clean off the 132 00:10:46,830 --> 00:10:47,550 slide 133 00:10:50,880 --> 00:10:54,240 90 right here, right here. Okay.

134 00:10:55,409 --> 00:10:56,399 10 Volts 135 00:10:57,990 --> 00:11:04,140 but now I've got 20 volts peak to peak. But now if it's 20 136 00:11:04,140 --> 00:11:07,500 volts peak to peak, that's a plus 137 00:11:08,730 --> 00:11:11,670 10 volts peak right here. 138 00:11:15,450 --> 00:11:18,150 So what do we have? We've got 10 volts 139 00:11:19,980 --> 00:11:27,690 plus 10 volts peak, what's VA gonna be? 20 volts. What are we 140 00:11:27,690 --> 00:11:32,430 going to be?

It's going to be plus 10 volts peak right here. 141 00:11:32,430 --> 00:11:38,220 If you can see that here, let me clear the slide off. We go. 142 00:11:38,669 --> 00:11:40,979 And there we go. 20 volts. 143 00:11:42,390 --> 00:11:43,920 VA is 20 volts.

144 00:11:44,220 --> 00:11:53,130 And VB at 90 degrees is 10 volts. PKC. Okay. Clear the 145 00:11:53,130 --> 00:11:58,980 slide, go to the next one. One ad. Well, one ad is still going 146 00:11:58,980 --> 00:12:03,780 to be the same as yours.

Over here. So we're going to get 147 00:12:03,780 --> 00:12:09,690 what? 10 volts for VA, and zero volts for VB. Let's go to 148 00:12:09,690 --> 00:12:16,440 272 70. Now, and again, let's clear the slide off. This is 149 00:12:16,440 --> 00:12:17,910 going to change a little bit 150 00:12:19,169 --> 00:12:20,999 to 70 is right here 151 00:12:24,000 --> 00:12:25,860 and VA. 152 00:12:27,059 --> 00:12:29,939 And let's do this one.

All right, let's put it up. 153 00:12:30,630 --> 00:12:38,340 Okay, so VA is still plus 10. But what is my bad What is my AC 154 00:12:38,340 --> 00:12:45,390 source minus 10 volts AC at that instant, at that instant, it's a 155 00:12:45,390 --> 00:12:53,700 minus 10 volt volt, a minus 10 volts AC. And plus 10 plus a 156 00:12:53,700 --> 00:13:00,930 minus 10 is zero. So right here, that's going to be zero volts. 157 00:13:02,250 --> 00:13:04,440 And again 360 158 00:13:06,089 --> 00:13:06,899 is like 159 00:13:07,679 --> 00:13:08,969 zero right there.

160 00:13:09,089 --> 00:13:11,309 So let me clear the slide off. 161 00:13:12,630 --> 00:13:16,260 And basically, let me show you what we've got. We've got right 162 00:13:16,260 --> 00:13:18,330 here, we've got a 163 00:13:18,809 --> 00:13:20,849 10 volts DC level. 164 00:13:22,320 --> 00:13:26,220 And we have an AC component going up here to 165 00:13:27,720 --> 00:13:29,280 20 volts peak. 166 00:13:30,929 --> 00:13:32,519 And down here, 167 00:13:33,900 --> 00:13:35,490 zero volts peak. 168 00:13:36,990 --> 00:13:41,130 Right if you if you notice it's still a 20 volt peak to peak 169 00:13:41,130 --> 00:13:46,350 swing.

20 Volts positive to zero volts is 20 volts, so there's 170 00:13:46,350 --> 00:13:52,380 still a 20 volts swing. What we've done here is we've level 171 00:13:52,380 --> 00:14:00,330 shifted up the DC component for this AC component to 10 volts So 172 00:14:00,330 --> 00:14:04,110 we levels shifted it up to 10 volts. So we've got an AC 173 00:14:04,110 --> 00:14:08,520 component of 20 volts peak to peak, riding on a 10 volt DC 174 00:14:08,520 --> 00:14:15,480 level. That's what we have. Okay, I have a problem here. I'd 175 00:14:15,480 --> 00:14:19,740 like you guys to fill in the chart right there.

And let's 176 00:14:19,740 --> 00:14:26,070 look at this. Okay, VA, VB and VCs right here, just like I did 177 00:14:26,070 --> 00:14:30,960 before, VA still is the battery for VA are the battery voltage, 178 00:14:30,960 --> 00:14:36,090 I should say is 10 volts. And we have a 30 volt peak to peak 179 00:14:36,090 --> 00:14:36,900 generator. 180 00:14:37,530 --> 00:14:38,580 So 181 00:14:43,260 --> 00:14:47,850 take a look at this, do it. If you have to hit the pause 182 00:14:47,850 --> 00:14:52,080 button, hit the pause button review the previous to try to 183 00:14:52,080 --> 00:14:55,320 fill in the blanks. That's the only way you're going to know 184 00:14:55,320 --> 00:14:59,910 how to do it is if you take the time to go through it and look 185 00:14:59,910 --> 00:15:06,390 at All right, again, the answers on the following slide.

I'm here 186 00:15:06,390 --> 00:15:12,090 to help you, but you need to try to do it on your own. Now one of 187 00:15:12,090 --> 00:15:14,610 the things you could do was go jump to the next slide and say, 188 00:15:14,610 --> 00:15:18,180 Oh, yeah, I know how to do it. Are you really gonna read if you 189 00:15:18,180 --> 00:15:21,450 don't put the effort, really write it down and look at it, 190 00:15:21,510 --> 00:15:24,600 analyze it to make sure you've done it right. Are you really 191 00:15:24,600 --> 00:15:25,560 gonna know how to do it? 192 00:15:25,770 --> 00:15:26,310 Maybe? 193 00:15:26,789 --> 00:15:32,129 I don't know you, but maybe some of you will.

But at least try to 194 00:15:32,129 --> 00:15:35,699 fill in the chart, hit the pause button, fill in the chart. All 195 00:15:35,699 --> 00:15:39,029 right. Now, we'll see on the next slide, we'll go over the 196 00:15:39,029 --> 00:15:39,569 answers. 197 00:15:45,150 --> 00:15:47,100 Okay, here are the answers to the problem. 198 00:15:48,630 --> 00:15:51,270 I'm not going to go through it. I'm just going to show it show 199 00:15:51,270 --> 00:15:57,420 you graphically here.

But what we have here is an AC component 200 00:15:58,680 --> 00:16:04,200 riding on a 10 volt DC level, okay at 30 volts peak to peak is 201 00:16:04,200 --> 00:16:05,460 my AC source. 202 00:16:06,270 --> 00:16:08,940 So what we're going to have here is 203 00:16:09,270 --> 00:16:10,260 10 volts, 204 00:16:11,010 --> 00:16:12,240 then we're going to go 205 00:16:12,870 --> 00:16:16,860 up to 25 volts peak here, plus 206 00:16:18,299 --> 00:16:19,349 at one ad 207 00:16:20,940 --> 00:16:23,100 we're going to see 10 volts. 208 00:16:24,809 --> 00:16:29,789 All right at 270. We're going below the zero volt line. 209 00:16:31,320 --> 00:16:33,900 So this is going to be a minus 210 00:16:34,380 --> 00:16:35,520 five volts 211 00:16:37,679 --> 00:16:38,579 right there, 212 00:16:39,330 --> 00:16:41,700 and then we're coming back to the zero line. 213 00:16:42,029 --> 00:16:49,649 So basically what we have here is a 10 volt DC level and a 30 214 00:16:49,649 --> 00:16:56,969 volt peak to peak AC component, because 25 volts to minus five 215 00:16:56,969 --> 00:17:04,139 volts is a 30 volts swing Okay, any questions on this?

Make sure 216 00:17:04,139 --> 00:17:08,999 you try it. If you've tried it, and you convinced you need a 217 00:17:08,999 --> 00:17:14,009 little help, give me a call, send me an email. I'm there for 218 00:17:14,009 --> 00:17:15,779 you. My first concern is to 219 00:17:16,169 --> 00:17:19,109 make sure you understand 220 00:17:19,319 --> 00:17:23,759 the material that I present. Okay, see on the next slide