[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.17,0:00:03.99,Default,,0000,0000,0000,,>> This is Dr. Cynthia Furse at the University of Utah.
Dialogue: 0,0:00:03.99,0:00:08.22,Default,,0000,0000,0000,,Today I'd like to talk about a very brief introduction to digital circuits.
Dialogue: 0,0:00:08.22,0:00:10.29,Default,,0000,0000,0000,,First, we are going to talk about analog and
Dialogue: 0,0:00:10.29,0:00:13.14,Default,,0000,0000,0000,,digital numbers and how these numbers are used for math.
Dialogue: 0,0:00:13.14,0:00:16.38,Default,,0000,0000,0000,,Then we'll talk about how computers use binary numbers and
Dialogue: 0,0:00:16.38,0:00:18.15,Default,,0000,0000,0000,,the digital logic gates that would be inside
Dialogue: 0,0:00:18.15,0:00:21.80,Default,,0000,0000,0000,,the computer and then finally how to hook up these digital circuits.
Dialogue: 0,0:00:21.80,0:00:24.28,Default,,0000,0000,0000,,Digital is basically a fixed value.
Dialogue: 0,0:00:24.28,0:00:26.37,Default,,0000,0000,0000,,It can take on one or a few values.
Dialogue: 0,0:00:26.37,0:00:27.78,Default,,0000,0000,0000,,It's something you can count.
Dialogue: 0,0:00:27.78,0:00:30.70,Default,,0000,0000,0000,,Digital is like the digits on your hand.
Dialogue: 0,0:00:30.70,0:00:32.43,Default,,0000,0000,0000,,Analog values vary.
Dialogue: 0,0:00:32.43,0:00:34.00,Default,,0000,0000,0000,,They can take on any value.
Dialogue: 0,0:00:34.00,0:00:35.44,Default,,0000,0000,0000,,They're something you can measure,
Dialogue: 0,0:00:35.44,0:00:38.34,Default,,0000,0000,0000,,such as the distance between your hands.
Dialogue: 0,0:00:38.34,0:00:40.84,Default,,0000,0000,0000,,Let's think of a fuel gauge for instance.
Dialogue: 0,0:00:40.84,0:00:43.67,Default,,0000,0000,0000,,The analog gauge, the circle across the top,
Dialogue: 0,0:00:43.67,0:00:45.41,Default,,0000,0000,0000,,tells you how much fuel you have.
Dialogue: 0,0:00:45.41,0:00:49.13,Default,,0000,0000,0000,,You have a full tank or a half a tank or a little more than a half a tank of gas.
Dialogue: 0,0:00:49.13,0:00:51.50,Default,,0000,0000,0000,,But when you're just about ready to run out,
Dialogue: 0,0:00:51.50,0:00:54.58,Default,,0000,0000,0000,,the digital light turns on to tell you that you either
Dialogue: 0,0:00:54.58,0:00:58.24,Default,,0000,0000,0000,,don't have enough when the light is on or that you do when the light is off.
Dialogue: 0,0:00:58.24,0:01:01.96,Default,,0000,0000,0000,,There are two choices: You either have enough fuel or you don't.
Dialogue: 0,0:01:01.96,0:01:05.38,Default,,0000,0000,0000,,Analog versus digital clocks both tell us time.
Dialogue: 0,0:01:05.38,0:01:09.36,Default,,0000,0000,0000,,The analog clock tells us what time it is in a continuous fashion.
Dialogue: 0,0:01:09.36,0:01:12.59,Default,,0000,0000,0000,,For example, here it's just a little before 12:40.
Dialogue: 0,0:01:12.59,0:01:15.74,Default,,0000,0000,0000,,The digital clock tells us what hour and minute it is.
Dialogue: 0,0:01:15.74,0:01:18.68,Default,,0000,0000,0000,,That's a countable number of hours and minutes.
Dialogue: 0,0:01:18.68,0:01:23.56,Default,,0000,0000,0000,,One of my favorite applications of analog and digital is in audio recording.
Dialogue: 0,0:01:23.56,0:01:26.93,Default,,0000,0000,0000,,Dr. Tom Stockham was a professor at the University of Utah.
Dialogue: 0,0:01:26.93,0:01:30.62,Default,,0000,0000,0000,,He was a big fan of opera particularly, Enrico Caruso,
Dialogue: 0,0:01:30.62,0:01:33.38,Default,,0000,0000,0000,,and he had a number of opera recordings that were done at the turn of
Dialogue: 0,0:01:33.38,0:01:36.52,Default,,0000,0000,0000,,the century when the recording instruments weren't very good.
Dialogue: 0,0:01:36.52,0:01:39.35,Default,,0000,0000,0000,,He wanted to be able to remove the old distortion from
Dialogue: 0,0:01:39.35,0:01:43.82,Default,,0000,0000,0000,,these recordings so that he could hear this marvelous opera singer in better precision.
Dialogue: 0,0:01:43.82,0:01:45.71,Default,,0000,0000,0000,,So, he took the analog recordings,
Dialogue: 0,0:01:45.71,0:01:47.30,Default,,0000,0000,0000,,the tapes that you see here,
Dialogue: 0,0:01:47.30,0:01:48.88,Default,,0000,0000,0000,,and converted them to digital.
Dialogue: 0,0:01:48.88,0:01:52.59,Default,,0000,0000,0000,,He's considered the father of modern digital recording or the CD,
Dialogue: 0,0:01:52.59,0:01:55.34,Default,,0000,0000,0000,,and he really did that to remove the distortion.
Dialogue: 0,0:01:55.34,0:01:59.27,Default,,0000,0000,0000,,There are many other reasons you might watch a record things in digital as well,
Dialogue: 0,0:01:59.27,0:02:04.76,Default,,0000,0000,0000,,but the original application was to remove the distortion from opera recordings.
Dialogue: 0,0:02:04.76,0:02:07.67,Default,,0000,0000,0000,,Analog versus digital is very important in
Dialogue: 0,0:02:07.67,0:02:09.89,Default,,0000,0000,0000,,the types of measurement equipment we use also,
Dialogue: 0,0:02:09.89,0:02:11.96,Default,,0000,0000,0000,,such as the volt meter shown here.
Dialogue: 0,0:02:11.96,0:02:16.38,Default,,0000,0000,0000,,An analog voltmeter tells you what voltage it is in a continuous fashion.
Dialogue: 0,0:02:16.38,0:02:20.12,Default,,0000,0000,0000,,The digital voltmeter is what you're familiar with on the myDAQ that
Dialogue: 0,0:02:20.12,0:02:24.11,Default,,0000,0000,0000,,tells you the voltage to within a certain countable number of digits.
Dialogue: 0,0:02:24.11,0:02:26.09,Default,,0000,0000,0000,,There also are vault testers,
Dialogue: 0,0:02:26.09,0:02:29.15,Default,,0000,0000,0000,,such as the craftsman design shown here that tell
Dialogue: 0,0:02:29.15,0:02:33.26,Default,,0000,0000,0000,,you if the voltage is on or off that would be true digital.
Dialogue: 0,0:02:33.26,0:02:35.52,Default,,0000,0000,0000,,When we talk about voltages,
Dialogue: 0,0:02:35.52,0:02:38.15,Default,,0000,0000,0000,,an analog voltage can have any value,
Dialogue: 0,0:02:38.15,0:02:40.98,Default,,0000,0000,0000,,such as the voltage going into a light bulb from a dimmer switch.
Dialogue: 0,0:02:40.98,0:02:44.51,Default,,0000,0000,0000,,The light will turn on at any little tiny amount of value.
Dialogue: 0,0:02:44.51,0:02:47.27,Default,,0000,0000,0000,,It's basically potentiometer that
Dialogue: 0,0:02:47.27,0:02:50.36,Default,,0000,0000,0000,,controls the amount of voltage that's getting to the light.
Dialogue: 0,0:02:50.36,0:02:53.41,Default,,0000,0000,0000,,A digital voltage is a very limited set of voltages,
Dialogue: 0,0:02:53.41,0:02:55.48,Default,,0000,0000,0000,,more typical of your traditional switch.
Dialogue: 0,0:02:55.48,0:02:56.87,Default,,0000,0000,0000,,The light is either on,
Dialogue: 0,0:02:56.87,0:02:59.63,Default,,0000,0000,0000,,1, or it's off, 0.
Dialogue: 0,0:02:59.63,0:03:02.68,Default,,0000,0000,0000,,An analog voltage can have any value,
Dialogue: 0,0:03:02.68,0:03:05.08,Default,,0000,0000,0000,,such as this swirl that's shown here.
Dialogue: 0,0:03:05.08,0:03:07.97,Default,,0000,0000,0000,,A digital voltage has a limited set of values,
Dialogue: 0,0:03:07.97,0:03:12.32,Default,,0000,0000,0000,,a limited set of steps such as this stair step voltage shown here.
Dialogue: 0,0:03:12.32,0:03:16.30,Default,,0000,0000,0000,,Digital voltages are represented with binary numbers.
Dialogue: 0,0:03:16.30,0:03:18.56,Default,,0000,0000,0000,,The analog voltage, this dashed line,
Dialogue: 0,0:03:18.56,0:03:20.88,Default,,0000,0000,0000,,you can see is a continuous solid line.
Dialogue: 0,0:03:20.88,0:03:23.72,Default,,0000,0000,0000,,If we wanted to say that full-scale is eight and we
Dialogue: 0,0:03:23.72,0:03:26.47,Default,,0000,0000,0000,,wanted to divide that into eight individual sets,
Dialogue: 0,0:03:26.47,0:03:29.69,Default,,0000,0000,0000,,that would be one way that we could represent digital values.
Dialogue: 0,0:03:29.69,0:03:33.11,Default,,0000,0000,0000,,So our value is either less than one-eighth,
Dialogue: 0,0:03:33.11,0:03:35.72,Default,,0000,0000,0000,,it's 0, or it's one-eighth,
Dialogue: 0,0:03:35.72,0:03:38.74,Default,,0000,0000,0000,,two-eighths, three-eighths, four-eighths and so on.
Dialogue: 0,0:03:38.74,0:03:41.31,Default,,0000,0000,0000,,Here's the digital code
Dialogue: 0,0:03:43.78,0:03:49.74,Default,,0000,0000,0000,,that could be used to represent the digital representation of the analog value.
Dialogue: 0,0:03:49.74,0:03:53.00,Default,,0000,0000,0000,,We use analog to digital conversion to convert
Dialogue: 0,0:03:53.00,0:03:56.14,Default,,0000,0000,0000,,between the analog value and the stair step digital value,
Dialogue: 0,0:03:56.14,0:03:59.26,Default,,0000,0000,0000,,and we use digital to analog value to convert back.
Dialogue: 0,0:03:59.26,0:04:03.18,Default,,0000,0000,0000,,The error at each of these cases is called quantization error.
Dialogue: 0,0:04:03.18,0:04:06.10,Default,,0000,0000,0000,,Let's talk about counting with binary numbers.
Dialogue: 0,0:04:06.10,0:04:10.91,Default,,0000,0000,0000,,I'm going to use three bits of binary number here to represent a 0.
Dialogue: 0,0:04:10.91,0:04:12.77,Default,,0000,0000,0000,,If all of my lights are off,
Dialogue: 0,0:04:12.77,0:04:14.36,Default,,0000,0000,0000,,my value will be 0.
Dialogue: 0,0:04:14.36,0:04:15.56,Default,,0000,0000,0000,,If my first light is on,
Dialogue: 0,0:04:15.56,0:04:16.70,Default,,0000,0000,0000,,that will be a 1.
Dialogue: 0,0:04:16.70,0:04:20.14,Default,,0000,0000,0000,,If my second light is on and my first light is off, that's a 2.
Dialogue: 0,0:04:20.14,0:04:21.83,Default,,0000,0000,0000,,Here we have two lights that are on,
Dialogue: 0,0:04:21.83,0:04:23.64,Default,,0000,0000,0000,,that's a 3 and so on.
Dialogue: 0,0:04:23.64,0:04:25.61,Default,,0000,0000,0000,,The reason I have to do this is because
Dialogue: 0,0:04:25.61,0:04:29.45,Default,,0000,0000,0000,,the computer can only represent things that are either on or off,
Dialogue: 0,0:04:29.45,0:04:34.44,Default,,0000,0000,0000,,and this allows me to count from 0-7 in a binary sequence.
Dialogue: 0,0:04:34.44,0:04:39.12,Default,,0000,0000,0000,,We talk about bits and bytes and sure that you've heard about these in normal use.
Dialogue: 0,0:04:39.12,0:04:44.06,Default,,0000,0000,0000,,So, a bit is each one of these individual things with a light could be on or off.
Dialogue: 0,0:04:44.06,0:04:46.14,Default,,0000,0000,0000,,I've shown eight bits here.
Dialogue: 0,0:04:46.14,0:04:49.61,Default,,0000,0000,0000,,Eight bits total up to one byte.
Dialogue: 0,0:04:49.61,0:04:52.66,Default,,0000,0000,0000,,Computers represent numbers or sets of bits eight,
Dialogue: 0,0:04:52.66,0:04:54.20,Default,,0000,0000,0000,,16 or 32 bit,
Dialogue: 0,0:04:54.20,0:04:56.10,Default,,0000,0000,0000,,for example, and an exponent.
Dialogue: 0,0:04:56.10,0:04:58.13,Default,,0000,0000,0000,,So, if we wanted to count to 2,000,
Dialogue: 0,0:04:58.13,0:05:00.72,Default,,0000,0000,0000,,we would say that's 2 times 10 to the third.
Dialogue: 0,0:05:00.72,0:05:03.34,Default,,0000,0000,0000,,We'd represent that as 2,
Dialogue: 0,0:05:03.34,0:05:05.58,Default,,0000,0000,0000,,there's one light on and one light off,
Dialogue: 0,0:05:05.58,0:05:08.73,Default,,0000,0000,0000,,times 10 to the third. There's the 3.
Dialogue: 0,0:05:08.83,0:05:12.83,Default,,0000,0000,0000,,Computers represent letters with a code called ASCII.
Dialogue: 0,0:05:12.83,0:05:19.14,Default,,0000,0000,0000,,We use a single byte to represent A as 0100001.
Dialogue: 0,0:05:19.14,0:05:22.44,Default,,0000,0000,0000,,We also say this is a 4 1.
Dialogue: 0,0:05:22.44,0:05:24.70,Default,,0000,0000,0000,,So, A is equal to 41.
Dialogue: 0,0:05:24.70,0:05:27.40,Default,,0000,0000,0000,,B is 4 2.
Dialogue: 0,0:05:27.40,0:05:30.58,Default,,0000,0000,0000,,C is 4 3 and so on.
Dialogue: 0,0:05:30.58,0:05:34.12,Default,,0000,0000,0000,,Small a is still going to have the 1 on the end,
Dialogue: 0,0:05:34.12,0:05:35.44,Default,,0000,0000,0000,,but instead of having a 4,
Dialogue: 0,0:05:35.44,0:05:38.09,Default,,0000,0000,0000,,it's going to have 6 etc.
Dialogue: 0,0:05:38.09,0:05:39.76,Default,,0000,0000,0000,,So, just for fun,
Dialogue: 0,0:05:39.76,0:05:44.43,Default,,0000,0000,0000,,why don't you stop this recording and see if you can write your name in ASCII code.
Dialogue: 0,0:05:44.92,0:05:48.11,Default,,0000,0000,0000,,Computers represent pictures with pixels.
Dialogue: 0,0:05:48.11,0:05:50.49,Default,,0000,0000,0000,,You've seen this in your digital camera or your printer,
Dialogue: 0,0:05:50.49,0:05:54.41,Default,,0000,0000,0000,,how many dots per inch you might use for your printer or your scanner.
Dialogue: 0,0:05:54.41,0:05:58.30,Default,,0000,0000,0000,,The digital values could either be on and off or in this case I'm
Dialogue: 0,0:05:58.30,0:06:02.19,Default,,0000,0000,0000,,showing you grayscale for the letter a and then an analog value,.
Dialogue: 0,0:06:02.19,0:06:03.48,Default,,0000,0000,0000,,is it truly analog?
Dialogue: 0,0:06:03.48,0:06:08.36,Default,,0000,0000,0000,,No. It's probably actually just a higher number of pixels so you don't see the edges.
Dialogue: 0,0:06:08.36,0:06:13.27,Default,,0000,0000,0000,,Computer represents color as combinations of red,
Dialogue: 0,0:06:13.27,0:06:15.18,Default,,0000,0000,0000,,green and blue called RGB.
Dialogue: 0,0:06:15.18,0:06:16.79,Default,,0000,0000,0000,,You can see the red corner,
Dialogue: 0,0:06:16.79,0:06:19.10,Default,,0000,0000,0000,,green corner and blue corner of this curve,
Dialogue: 0,0:06:19.10,0:06:20.80,Default,,0000,0000,0000,,and as you add different combinations,
Dialogue: 0,0:06:20.80,0:06:24.28,Default,,0000,0000,0000,,you can actually get any color i the color system.
Dialogue: 0,0:06:24.28,0:06:30.30,Default,,0000,0000,0000,,Computer logic is going to use on and off, switches on and off.
Dialogue: 0,0:06:30.30,0:06:33.93,Default,,0000,0000,0000,,Computer circuits on and off representing 1 and 0,
Dialogue: 0,0:06:33.93,0:06:37.24,Default,,0000,0000,0000,,and these represent yes and no or true and false values.
Dialogue: 0,0:06:37.24,0:06:40.94,Default,,0000,0000,0000,,They're typically 5 and 0 volts.
Dialogue: 0,0:06:40.94,0:06:42.90,Default,,0000,0000,0000,,Let's go through an example.
Dialogue: 0,0:06:42.90,0:06:46.18,Default,,0000,0000,0000,,Let's suppose, we wanted to build a battery voltage sensing system,
Dialogue: 0,0:06:46.18,0:06:50.30,Default,,0000,0000,0000,,and a battery is considered low when its voltage is under 1.3.
Dialogue: 0,0:06:50.30,0:06:51.96,Default,,0000,0000,0000,,Let's say I've got two batteries.
Dialogue: 0,0:06:51.96,0:06:54.04,Default,,0000,0000,0000,,So, for example, I want to know,
Dialogue: 0,0:06:54.04,0:06:55.96,Default,,0000,0000,0000,,is this one battery charged?
Dialogue: 0,0:06:55.96,0:06:57.71,Default,,0000,0000,0000,,In ECE-speak, that is,
Dialogue: 0,0:06:57.71,0:07:00.65,Default,,0000,0000,0000,,is the battery voltage above 1.3 volts?
Dialogue: 0,0:07:00.65,0:07:04.32,Default,,0000,0000,0000,,So, what I'm going to do is convert this value to digital,
Dialogue: 0,0:07:04.32,0:07:06.56,Default,,0000,0000,0000,,a value of zero or five volts.
Dialogue: 0,0:07:06.56,0:07:09.98,Default,,0000,0000,0000,,We know one way to do that and that's with an op-amp circuit.
Dialogue: 0,0:07:09.98,0:07:12.74,Default,,0000,0000,0000,,I could put the battery into the positive terminal and
Dialogue: 0,0:07:12.74,0:07:16.20,Default,,0000,0000,0000,,the comparison voltage 1.3 volts into the negative terminal,
Dialogue: 0,0:07:16.20,0:07:21.42,Default,,0000,0000,0000,,and then if I used Vcc at five volts and zero volts here at my two rails,
Dialogue: 0,0:07:21.42,0:07:26.48,Default,,0000,0000,0000,,I know that my output would be a times vb minus 1.3.
Dialogue: 0,0:07:26.48,0:07:29.78,Default,,0000,0000,0000,,But it would whale out at either zero or five volts.
Dialogue: 0,0:07:29.78,0:07:32.86,Default,,0000,0000,0000,,That might be my digital 1 or my digital 0.
Dialogue: 0,0:07:32.86,0:07:34.90,Default,,0000,0000,0000,,If this happened to be equal to 0,
Dialogue: 0,0:07:34.90,0:07:37.16,Default,,0000,0000,0000,,my V0 would be 0.
Dialogue: 0,0:07:37.16,0:07:39.99,Default,,0000,0000,0000,,If the Vp was greater than Vn,
Dialogue: 0,0:07:39.99,0:07:41.46,Default,,0000,0000,0000,,my value would be 1.
Dialogue: 0,0:07:41.46,0:07:46.24,Default,,0000,0000,0000,,The battery is charged or if it's less then my battery would be 0,
Dialogue: 0,0:07:46.24,0:07:48.87,Default,,0000,0000,0000,,my battery is not charged.
Dialogue: 0,0:07:49.04,0:07:52.42,Default,,0000,0000,0000,,Now, let's see how that would play into logic gates.
Dialogue: 0,0:07:52.42,0:07:55.46,Default,,0000,0000,0000,,There are several types of circuits that are
Dialogue: 0,0:07:55.46,0:07:58.30,Default,,0000,0000,0000,,specifically meant to work on zero to five volts,
Dialogue: 0,0:07:58.30,0:08:01.28,Default,,0000,0000,0000,,and they are different types of gates.
Dialogue: 0,0:08:01.28,0:08:02.58,Default,,0000,0000,0000,,One type of gate here,
Dialogue: 0,0:08:02.58,0:08:05.24,Default,,0000,0000,0000,,for example, if I put in a 1,
Dialogue: 0,0:08:05.24,0:08:07.29,Default,,0000,0000,0000,,a five volt or a 0,
Dialogue: 0,0:08:07.29,0:08:09.59,Default,,0000,0000,0000,,a zero volt, this is what would happen.
Dialogue: 0,0:08:09.59,0:08:12.14,Default,,0000,0000,0000,,Let me bring in the input from
Dialogue: 0,0:08:12.14,0:08:15.48,Default,,0000,0000,0000,,one battery tester and the input from the other battery tester.
Dialogue: 0,0:08:15.48,0:08:17.36,Default,,0000,0000,0000,,If they were both 0,
Dialogue: 0,0:08:17.36,0:08:19.44,Default,,0000,0000,0000,,that means that both batteries are uncharged,
Dialogue: 0,0:08:19.44,0:08:21.05,Default,,0000,0000,0000,,I would get a 0.
Dialogue: 0,0:08:21.05,0:08:24.22,Default,,0000,0000,0000,,If one battery is uncharged and the other battery is charged,
Dialogue: 0,0:08:24.22,0:08:26.86,Default,,0000,0000,0000,,note, both batteries aren't charged, will still be a 0.
Dialogue: 0,0:08:26.86,0:08:29.72,Default,,0000,0000,0000,,If one battery is charged and the other battery is not, nope,
Dialogue: 0,0:08:29.72,0:08:31.06,Default,,0000,0000,0000,,they're still not both charged,
Dialogue: 0,0:08:31.06,0:08:32.55,Default,,0000,0000,0000,,but if they are both charged,
Dialogue: 0,0:08:32.55,0:08:34.48,Default,,0000,0000,0000,,I will get an output, a 1.
Dialogue: 0,0:08:34.48,0:08:36.14,Default,,0000,0000,0000,,If I measured that with a voltmeter,
Dialogue: 0,0:08:36.14,0:08:37.28,Default,,0000,0000,0000,,what would I see?
Dialogue: 0,0:08:37.28,0:08:40.28,Default,,0000,0000,0000,,I would see a five volts on the output circuit.
Dialogue: 0,0:08:40.28,0:08:41.83,Default,,0000,0000,0000,,This is called an AND gate.
Dialogue: 0,0:08:41.83,0:08:46.68,Default,,0000,0000,0000,,It tests to see if the two inputs are both 1.
Dialogue: 0,0:08:46.68,0:08:52.08,Default,,0000,0000,0000,,An OR gate is going to test to see if one or the other input is charged.
Dialogue: 0,0:08:52.08,0:08:53.91,Default,,0000,0000,0000,,So, I might be able to ask the question,
Dialogue: 0,0:08:53.91,0:08:56.34,Default,,0000,0000,0000,,is at least one of my batteries charged?
Dialogue: 0,0:08:56.34,0:09:00.12,Default,,0000,0000,0000,,So, then I would test to see is at least one of my batteries charged.
Dialogue: 0,0:09:00.12,0:09:01.96,Default,,0000,0000,0000,,So, here I have 0 and 0.
Dialogue: 0,0:09:01.96,0:09:04.38,Default,,0000,0000,0000,,No. Both batteries are uncharged in this case.
Dialogue: 0,0:09:04.38,0:09:05.82,Default,,0000,0000,0000,,So, I get a 0 output.
Dialogue: 0,0:09:05.82,0:09:07.90,Default,,0000,0000,0000,,Here, I have an uncharged and a charged.
Dialogue: 0,0:09:07.90,0:09:09.84,Default,,0000,0000,0000,,Yeah. One of my battery is charged.
Dialogue: 0,0:09:09.84,0:09:11.41,Default,,0000,0000,0000,,Here, the other battery is charged,
Dialogue: 0,0:09:11.41,0:09:14.94,Default,,0000,0000,0000,,and here both batteries are charged. That's an OR gate.
Dialogue: 0,0:09:14.94,0:09:16.78,Default,,0000,0000,0000,,Now, I could ask the question,
Dialogue: 0,0:09:16.78,0:09:19.45,Default,,0000,0000,0000,,does at least one of my batteries need to be charged?
Dialogue: 0,0:09:19.45,0:09:23.06,Default,,0000,0000,0000,,I could bring in the voltage from either of my battery testing circuits,
Dialogue: 0,0:09:23.06,0:09:25.42,Default,,0000,0000,0000,,and I will see if I have 0 and 0.
Dialogue: 0,0:09:25.42,0:09:26.56,Default,,0000,0000,0000,,They both need to be charged.
Dialogue: 0,0:09:26.56,0:09:28.10,Default,,0000,0000,0000,,Yeah. Need charging there.
Dialogue: 0,0:09:28.10,0:09:30.18,Default,,0000,0000,0000,,This one needs to be charged, this one doesn't.
Dialogue: 0,0:09:30.18,0:09:32.28,Default,,0000,0000,0000,,But, yes, I still need to get out my charger.
Dialogue: 0,0:09:32.28,0:09:34.00,Default,,0000,0000,0000,,This one's charged, that one's not,
Dialogue: 0,0:09:34.00,0:09:35.52,Default,,0000,0000,0000,,get out your charger again.
Dialogue: 0,0:09:35.52,0:09:36.82,Default,,0000,0000,0000,,Charged and charged.
Dialogue: 0,0:09:36.82,0:09:38.52,Default,,0000,0000,0000,,No. I don't need my charger.
Dialogue: 0,0:09:38.52,0:09:40.46,Default,,0000,0000,0000,,This is called a NAND gate,
Dialogue: 0,0:09:40.46,0:09:42.30,Default,,0000,0000,0000,,N for NOT AND.
Dialogue: 0,0:09:42.30,0:09:45.40,Default,,0000,0000,0000,,Here are some other circuits that you could do.
Dialogue: 0,0:09:45.40,0:09:47.81,Default,,0000,0000,0000,,A NOT gate just inverts your circuit.
Dialogue: 0,0:09:47.81,0:09:49.28,Default,,0000,0000,0000,,If it comes in as a 0,
Dialogue: 0,0:09:49.28,0:09:50.50,Default,,0000,0000,0000,,it'll change it to a 1.
Dialogue: 0,0:09:50.50,0:09:53.18,Default,,0000,0000,0000,,If it comes in a 1, it'll change it to a 0.
Dialogue: 0,0:09:53.18,0:09:54.74,Default,,0000,0000,0000,,Here's an exclusive or.
Dialogue: 0,0:09:54.74,0:09:58.22,Default,,0000,0000,0000,,You're actually going to use this in your next lab. This is how it works.
Dialogue: 0,0:09:58.22,0:10:01.26,Default,,0000,0000,0000,,If they are both 0, then the output is 0.
Dialogue: 0,0:10:01.26,0:10:03.59,Default,,0000,0000,0000,,If it is 0 and 1, the output is 1.
Dialogue: 0,0:10:03.59,0:10:05.24,Default,,0000,0000,0000,,1 and 0, the output is 1.
Dialogue: 0,0:10:05.24,0:10:07.30,Default,,0000,0000,0000,,Or 1 and 1, the output is 0.
Dialogue: 0,0:10:07.30,0:10:14.86,Default,,0000,0000,0000,,This circuit is telling you if there's a difference between your two testers.
Dialogue: 0,0:10:15.77,0:10:18.92,Default,,0000,0000,0000,,Now, let's talk about building with logic gates.
Dialogue: 0,0:10:18.92,0:10:23.82,Default,,0000,0000,0000,,Remember when you use the op-amp you had to be able to put a power supply voltage on it,
Dialogue: 0,0:10:23.82,0:10:25.30,Default,,0000,0000,0000,,you have to hear also.
Dialogue: 0,0:10:25.30,0:10:29.08,Default,,0000,0000,0000,,Normally Vss will be five volts and Vdd will be ground.
Dialogue: 0,0:10:29.08,0:10:30.85,Default,,0000,0000,0000,,You have this little chip right here,
Dialogue: 0,0:10:30.85,0:10:33.89,Default,,0000,0000,0000,,and let's suppose we want to hook up an AND gate where we have
Dialogue: 0,0:10:33.89,0:10:37.42,Default,,0000,0000,0000,,an input A and an input B and an output.
Dialogue: 0,0:10:37.42,0:10:39.30,Default,,0000,0000,0000,,Right here is the input A,
Dialogue: 0,0:10:39.30,0:10:41.10,Default,,0000,0000,0000,,the input B and the output.
Dialogue: 0,0:10:41.10,0:10:44.09,Default,,0000,0000,0000,,The chip, this is the part that goes on your breadboard,
Dialogue: 0,0:10:44.09,0:10:46.75,Default,,0000,0000,0000,,will typically have four AND gates,
Dialogue: 0,0:10:46.75,0:10:50.28,Default,,0000,0000,0000,,each of them with separate input and outputs as shown.
Dialogue: 0,0:10:50.30,0:10:54.00,Default,,0000,0000,0000,,So, that's a really fast introduction to digital circuits.
Dialogue: 0,0:10:54.00,0:10:56.96,Default,,0000,0000,0000,,We compared analog and digital ideas,
Dialogue: 0,0:10:56.96,0:11:00.59,Default,,0000,0000,0000,,as well as talked a little bit about digital numbers and their binary math,
Dialogue: 0,0:11:00.59,0:11:04.100,Default,,0000,0000,0000,,how computers use these numbers and these types of logic gates, NOT,
Dialogue: 0,0:11:04.100,0:11:07.84,Default,,0000,0000,0000,,OR, XOR, AND and NAND,
Dialogue: 0,0:11:07.84,0:11:10.84,Default,,0000,0000,0000,,and then just briefly how to hook them up.
Dialogue: 0,0:11:10.84,0:11:13.19,Default,,0000,0000,0000,,Thank you very much for joining me,
Dialogue: 0,0:11:13.19,0:11:19.14,Default,,0000,0000,0000,,and this video is brought to you from Tombstone Rock near Moab, Utah.