WEBVTT 1 00:00:00.080 --> 00:00:02.640 Have you ever looked at a circuit board, you know, 2 00:00:02.680 --> 00:00:05.200 all those tiny little bits and pieces and just felt 3 00:00:05.240 --> 00:00:07.799 totally lost, like it's some secret code. 4 00:00:07.879 --> 00:00:10.320 Oh yeah, Or maybe you've just had that urge, you know, 5 00:00:10.480 --> 00:00:14.199 to tinker to make something work, or maybe fix an 6 00:00:14.240 --> 00:00:14.880 old gadget. 7 00:00:15.080 --> 00:00:19.000 Exactly. There's just this amazing feeling when you figure out 8 00:00:19.000 --> 00:00:22.480 how something clicks right, adapting tech with your own hands, 9 00:00:22.920 --> 00:00:24.879 making something new, And the best. 10 00:00:24.600 --> 00:00:29.120 Part, you really really don't need some fancy engineering degree 11 00:00:29.320 --> 00:00:31.320 or like tons of complex math. 12 00:00:31.519 --> 00:00:34.320 No, not at all. It's more about just being curious 13 00:00:34.640 --> 00:00:37.799 and having that just do it kind of attitude. 14 00:00:37.920 --> 00:00:40.759 And that, my friend, that's exactly what we're diving into today. 15 00:00:40.840 --> 00:00:42.039 Welcome to the deep dive. 16 00:00:42.159 --> 00:00:45.600 Yep, we're digging into a really cool source, hacking electronics. 17 00:00:46.039 --> 00:00:49.079 An illustrated DIY guy for makers and hobbyists. 18 00:00:49.320 --> 00:00:52.119 Our mission basically is to cut through the noise, grab 19 00:00:52.159 --> 00:00:54.359 the most important stuff, and give you a shortcut to 20 00:00:54.439 --> 00:00:57.960 feeling confident with practical electronics. You're gonna have some real 21 00:00:58.039 --> 00:01:00.000 aha moments, I think definitely. 22 00:01:00.119 --> 00:01:02.159 So what's the plan. Well, we'll walk you through the basics, 23 00:01:02.240 --> 00:01:04.840 like what tools you actually need, and don't worry, it's 24 00:01:04.879 --> 00:01:05.959 not expensive. 25 00:01:06.280 --> 00:01:10.280 And understanding the fundamentals current resistance, voltage, all that stuff. 26 00:01:10.319 --> 00:01:13.239 Then we get to the fun parts, lighting up LEDs, 27 00:01:13.400 --> 00:01:14.560 powering your projects. 28 00:01:14.760 --> 00:01:17.760 We're even talking building a small robot maybe, or like 29 00:01:17.879 --> 00:01:20.840 a toy you can control from a web page. Super cool. 30 00:01:20.920 --> 00:01:24.599 It's all about practical hands on stuff, getting those electrons 31 00:01:25.040 --> 00:01:26.680 doing what you want them to do. You know. 32 00:01:26.799 --> 00:01:30.040 The core idea of this guide is really this just 33 00:01:30.239 --> 00:01:32.959 do it philosophy for hacking electronics. 34 00:01:33.120 --> 00:01:33.319 Right. 35 00:01:33.400 --> 00:01:36.480 It basically says, look, the moment you decide you want 36 00:01:36.519 --> 00:01:39.560 to build something or modify something, you're already qualified. 37 00:01:39.879 --> 00:01:41.480 Huh. I like that? 38 00:01:41.640 --> 00:01:44.840 Seriously. The best way, the only way really to learn, 39 00:01:44.879 --> 00:01:46.879 is by rolling up your sleeves and just trying things. 40 00:01:46.959 --> 00:01:49.799 And mistakes are okay, mistakes are great. They're not failures. 41 00:01:49.840 --> 00:01:53.640 They're just learning opportunities, just as valuable as getting it 42 00:01:53.719 --> 00:01:55.799 right the first time, maybe even more so sometimes. 43 00:01:55.920 --> 00:01:58.239 You know, that's such a refreshing approach compared to those 44 00:01:59.599 --> 00:02:01.319 terrified textbooks full of theory. 45 00:02:01.439 --> 00:02:05.120 First totally, this flips it. Get your hands dirty, build something, 46 00:02:05.239 --> 00:02:07.439 then maybe dig into the why if you're curious. 47 00:02:07.840 --> 00:02:10.400 It taps into that natural curiosity, right. It makes it 48 00:02:10.400 --> 00:02:12.120 feel like playing experiments. 49 00:02:11.719 --> 00:02:14.199 Exactly and you learn faster that way. I think you 50 00:02:14.240 --> 00:02:17.960 get an intuition for why things work and why they 51 00:02:18.039 --> 00:02:19.319 sometimes well don't. 52 00:02:19.240 --> 00:02:25.960 Practical intelligence love it? Okay? So getting started, people probably 53 00:02:26.000 --> 00:02:29.639 think they need a whole lab right, expensive gear, Nah, 54 00:02:29.759 --> 00:02:30.199 not at all. 55 00:02:30.240 --> 00:02:33.840 That's the beauty of it. The book suggests a really minimal, 56 00:02:34.039 --> 00:02:38.240 cheap toolkit to start, like a masic soldering iron, okay, 57 00:02:38.319 --> 00:02:42.400 some solder a stand for the iron, important flyers, snips, 58 00:02:42.400 --> 00:02:44.479 maybe a few screwdrivers. 59 00:02:43.879 --> 00:02:46.680 Like basic kitchen tools, but for electronics pretty much. 60 00:02:46.759 --> 00:02:50.240 And then the one really invaluable tool is a digital multimeter. 61 00:02:50.599 --> 00:02:51.759 Ah, the DMM. 62 00:02:51.960 --> 00:02:54.400 Yeah, and again don't need to break the bank. Under 63 00:02:54.400 --> 00:02:55.879 twenty bucks gets you a decent one. 64 00:02:55.919 --> 00:02:57.560 And what are the key things you'll measure with it? 65 00:02:57.599 --> 00:03:01.919 Mostly DC volts, DC current resistance. Oh and the continuity 66 00:03:01.960 --> 00:03:04.400 test that beeping thing super useful. 67 00:03:04.120 --> 00:03:07.680 Gotcha okay? And for actually trying out circuits before solder. 68 00:03:07.520 --> 00:03:10.240 Red boards SOLDERI list breadboards. They are just fantastic for 69 00:03:10.319 --> 00:03:11.280 quickly trying designs. 70 00:03:11.360 --> 00:03:13.840 You just poke the component legs into the les. 71 00:03:13.960 --> 00:03:17.599 Yep, and underneath there are these metal clips connecting rows 72 00:03:17.639 --> 00:03:20.919 of holes, so you just push wires in to connect 73 00:03:20.960 --> 00:03:21.360 things up. 74 00:03:21.719 --> 00:03:22.639 And you mentioned wire. 75 00:03:22.800 --> 00:03:26.000 Yeah, grab some solid core wire. Different colors help a lot, 76 00:03:26.120 --> 00:03:30.319 like use red for positive voltage, black for negative or ground. 77 00:03:30.000 --> 00:03:31.479 Makes it easier to see what's going on. 78 00:03:31.479 --> 00:03:34.960 Totally keep things organized. Maybe yellow or blue for signals. 79 00:03:35.120 --> 00:03:37.840 Okay, and are all wires the same, good question? 80 00:03:38.039 --> 00:03:42.759 No, that solid core wires sometimes called hookup wire. Great 81 00:03:42.800 --> 00:03:46.039 for breadboards because it's stiff, easy to push in, but 82 00:03:46.039 --> 00:03:48.879 but it can break if you bend it back and 83 00:03:48.919 --> 00:03:49.840 forth too many times. 84 00:03:50.000 --> 00:03:53.560 Uh. Okay, So for connecting say, different modules. 85 00:03:53.159 --> 00:03:55.680 Together, Yeah, for that, multi core wire is better. It's 86 00:03:55.680 --> 00:03:59.280 more flexible. And hey, pro tip, you can often salvage 87 00:03:59.319 --> 00:04:01.840 good wire from old broken electronics save some money. 88 00:04:02.039 --> 00:04:05.319 Nice the hacker way. Yeah, and what about audio cables 89 00:04:05.319 --> 00:04:06.520 they seem different? They are. 90 00:04:06.639 --> 00:04:09.800 That's usually screened wire. It's designed to stop electrical noise, 91 00:04:09.879 --> 00:04:12.719 like that annoying hum from your main's power, from messing 92 00:04:12.800 --> 00:04:14.159 up sensitive audio signals. 93 00:04:14.199 --> 00:04:14.719 How's it work? 94 00:04:14.879 --> 00:04:18.360 It's clever. There's an inner wire or wires carrying the signal, 95 00:04:18.560 --> 00:04:21.920 and that's surrounded by a woven metal sheath like a shield. 96 00:04:22.240 --> 00:04:23.639 That shield blocks the noise. 97 00:04:23.800 --> 00:04:26.959 Elegant. Okay, so you have wires. Yeah, you need to 98 00:04:26.959 --> 00:04:28.120 strip the ends right, yep. 99 00:04:28.639 --> 00:04:31.319 You can buy wire strippers, sure, but the book shows 100 00:04:31.319 --> 00:04:33.319 you can actually do a pretty decent job with just 101 00:04:33.480 --> 00:04:34.560 pliers and snips. 102 00:04:34.839 --> 00:04:36.680 Takes practice, I beg It takes a little practice. 103 00:04:36.759 --> 00:04:39.319 Yeah, you gotta be careful not to nick the wire 104 00:04:39.399 --> 00:04:42.759 inside or stretch the insulation. But it works. 105 00:04:42.959 --> 00:04:46.519 And joining wires, but if you can't soder right away. 106 00:04:46.759 --> 00:04:49.839 Quick and dirty method, just twist them together works okay 107 00:04:49.839 --> 00:04:54.680 for multicore wire. Twist the strands of each wire tight clockwise. 108 00:04:55.160 --> 00:04:58.199 Then twist the two wires together, make a little knot maybe, 109 00:04:58.480 --> 00:05:01.600 and wrap it well with PBC tape. Good temporary fix. 110 00:05:01.439 --> 00:05:03.360 But for permanent stuff it's got to be Solder. 111 00:05:03.160 --> 00:05:05.959 Soldering is the main skill. Really, It unlocks so much. 112 00:05:06.120 --> 00:05:08.439 But safety first, always right. 113 00:05:08.519 --> 00:05:10.560 Hot metal fumes exactly. 114 00:05:10.120 --> 00:05:12.879 Hot iron means molten metal, nasty fumes. You don't want 115 00:05:12.879 --> 00:05:16.079 to breathe, so always use a stand for the iron always, okay, 116 00:05:16.120 --> 00:05:19.920 Wear safety glasses. Molten solder can splash seriously. 117 00:05:20.560 --> 00:05:21.920 Ouch, okay glasses. 118 00:05:22.319 --> 00:05:24.399 If you do get a burn, run it under cold 119 00:05:24.399 --> 00:05:28.480 water immediately, and solder in a well ventilated space. Use 120 00:05:28.519 --> 00:05:31.199 a small fan maybe to pull the fumes away from 121 00:05:31.199 --> 00:05:31.680 your face. 122 00:05:31.879 --> 00:05:35.920 Good tips. What about holding tiny components while you solder? 123 00:05:36.120 --> 00:05:40.120 Ah? Yeah, those helping hands tools with the clips. They're 124 00:05:40.120 --> 00:05:43.439 not essential, but man they are a great help. Highly recommend. 125 00:05:43.439 --> 00:05:45.800 Getting some makes sense. So how do you actually solder 126 00:05:45.800 --> 00:05:46.519 wires together? 127 00:05:46.680 --> 00:05:48.959 Two main ways. You can do that twist we talked about. 128 00:05:48.959 --> 00:05:52.279 Then just flow solder into the not works fine, Or 129 00:05:52.439 --> 00:05:56.240 for a cleaner, joint, less lumpy, you tin each wire first. 130 00:05:56.439 --> 00:05:59.160 Just coat them lightly with solder, then hold the tinned 131 00:05:59.279 --> 00:06:01.600 end side by, heat them both with the iron and 132 00:06:01.680 --> 00:06:03.720 let the solder fuse them. Then insulate it. 133 00:06:03.759 --> 00:06:06.040 Of course, it's got it. And how do you check 134 00:06:06.040 --> 00:06:09.160 if your connection is actually good or if wire is broken? Somewhere? 135 00:06:09.199 --> 00:06:11.839 Back to the multimeter that continuity mode. 136 00:06:11.720 --> 00:06:13.519 The beeping one, the beeping one. 137 00:06:13.720 --> 00:06:16.120 If it beeps when you touch the probes to two points, 138 00:06:16.160 --> 00:06:19.240 it means there's a connection. No beep, no connection, simple 139 00:06:19.240 --> 00:06:19.600 as that. 140 00:06:19.639 --> 00:06:22.040 What could cause a bad connection after soldering? 141 00:06:22.319 --> 00:06:24.959 Often it's a dry joint that's where the solder didn't 142 00:06:24.959 --> 00:06:28.480 flow properly, didn't really bond, or maybe a tiny crack 143 00:06:28.480 --> 00:06:29.560 in a circuit board track. 144 00:06:29.759 --> 00:06:30.720 Are those hard to fix? 145 00:06:31.240 --> 00:06:35.079 Usually not dry joints, just reheat and add a tiny 146 00:06:35.120 --> 00:06:38.959 bit more solder track cracks. Carefully scrape off the green 147 00:06:39.040 --> 00:06:41.920 lacquer on either side, and bridge the gap with solder. 148 00:06:42.319 --> 00:06:46.199 Easy pasy cool. So the book uses a project to 149 00:06:46.240 --> 00:06:48.399 illustrate this, the fume extractor. 150 00:06:48.680 --> 00:06:51.120 Yeah it's a great first practical hack. We just talked 151 00:06:51.160 --> 00:06:52.360 about solder fumes. 152 00:06:52.079 --> 00:06:54.079 Being bad, right right, nasty stuff. 153 00:06:54.439 --> 00:06:57.639 So the hack is dead simple. Take an old computer fan, 154 00:06:57.920 --> 00:07:00.000 hook it up to a switch and a twelve volt pad. 155 00:07:00.279 --> 00:07:03.240 Supply point it so it blows the fumes away from you. 156 00:07:03.319 --> 00:07:04.920 Functional, not fancy. 157 00:07:04.519 --> 00:07:08.399 Exactly, and this super simple project becomes your first lesson 158 00:07:08.439 --> 00:07:11.040 in reading schematics. Those circuit diagrams, yeah. 159 00:07:10.839 --> 00:07:12.439 They always look like hieroglyphics to me. 160 00:07:12.560 --> 00:07:14.759 They can seem this way, but the book breaks it 161 00:07:14.839 --> 00:07:18.279 down few simple rules. Positive voltage is usually shown at 162 00:07:18.279 --> 00:07:20.800 the top. Okay, Things generally happen kind of left to 163 00:07:20.879 --> 00:07:24.360 right like reading. Components have label like S one for switch, 164 00:07:24.399 --> 00:07:25.600 one M for motor. 165 00:07:25.759 --> 00:07:28.360 Ah. Okay, makes sense, And you. 166 00:07:28.399 --> 00:07:31.839 Learn how to check power supply polarity with your multimeter. 167 00:07:31.920 --> 00:07:34.920 Look for the dc VULT symbol the solid line over 168 00:07:34.959 --> 00:07:38.879 the dotted line. Knowing these little visual rules makes schematics 169 00:07:39.079 --> 00:07:39.959 way less scary. 170 00:07:40.279 --> 00:07:43.839 Okay, good, So fundamentals, let's talk about the really core stuff. 171 00:07:44.279 --> 00:07:49.079 Current resistance, voltage. Power sounds heavy. 172 00:07:48.879 --> 00:07:51.439 It sounds heavy, but the analogies in the book are brilliant, 173 00:07:51.639 --> 00:07:55.160 makes it really click. Current think of electrons like little 174 00:07:55.199 --> 00:07:58.560 balls flowing through pipes, or just current in a river. 175 00:07:59.079 --> 00:08:00.680 So how much stuff is flowing per second? 176 00:08:00.759 --> 00:08:03.759 Exactly measured in amps? Okay? So if current is the 177 00:08:03.879 --> 00:08:06.120 river flow, what's resistance? 178 00:08:06.519 --> 00:08:09.319 Ah, something slowing it down like rocks in the river. 179 00:08:09.480 --> 00:08:12.519 Perfect a resistor resists the flow. It's like a constriction 180 00:08:12.680 --> 00:08:15.480 a narrow part of the river. More resistance, less flow 181 00:08:15.720 --> 00:08:16.959 measured in ohms. 182 00:08:16.959 --> 00:08:17.839 Okay, okay. 183 00:08:17.879 --> 00:08:20.920 And voltage sticking with the river, voltage is like the 184 00:08:20.959 --> 00:08:23.079 height difference the slope of the river bed. A bigger 185 00:08:23.160 --> 00:08:25.639 drop in height, faster flow, more push. 186 00:08:25.759 --> 00:08:27.240 So it's a difference between two points. 187 00:08:27.279 --> 00:08:30.920 Always voltage is relative. You need that potential difference, that 188 00:08:31.040 --> 00:08:33.600 drop for current to flow measured in volts. 189 00:08:33.879 --> 00:08:37.759 Right, So how do these three current voltage resistance relate? 190 00:08:37.879 --> 00:08:39.200 Is there like a magic formula? 191 00:08:39.440 --> 00:08:42.840 There is, and it's probably the single most useful thing 192 00:08:42.879 --> 00:08:45.000 in basic electronics. Ohm's law. 193 00:08:45.120 --> 00:08:46.480 Ohm's law Okay, it's simple. 194 00:08:46.720 --> 00:08:50.240 I equals V divided by R. Current equals voltage divided 195 00:08:50.240 --> 00:08:51.519 by resistance. 196 00:08:51.080 --> 00:08:52.519 I equals v R. 197 00:08:53.039 --> 00:08:55.200 Got it. So voltage goes up, current goes up, and 198 00:08:55.200 --> 00:08:56.120 if resistance goes. 199 00:08:56.000 --> 00:08:58.399 Up, current goes down. Makes intuitive sense, right? Yeah? 200 00:08:58.440 --> 00:09:00.679 Actually it does. Can you give a quick examp numbers? 201 00:09:00.759 --> 00:09:03.399 Sure? Say you have ten volts across a one hundred 202 00:09:03.480 --> 00:09:06.240 OM resistor. Ten divided by one hundred is point one, 203 00:09:06.320 --> 00:09:08.600 so point one amps or one hundred million amps of 204 00:09:08.679 --> 00:09:09.440 current will flow. 205 00:09:09.639 --> 00:09:13.000 Okay, I see how that works. Simple relationship. What about power? 206 00:09:13.360 --> 00:09:17.240 Power is basically energy being used or transformed, usually into 207 00:09:17.240 --> 00:09:20.679 heat over time. As current flows through resistance, things can 208 00:09:20.720 --> 00:09:21.159 get warm. 209 00:09:21.240 --> 00:09:22.519 And there's a formula for that too. 210 00:09:22.639 --> 00:09:24.960 Yep. The main one is P equals I times V. 211 00:09:25.240 --> 00:09:29.080 Power equals current times voltage measured in watts ev. You 212 00:09:29.159 --> 00:09:32.080 also see p I squared R or PV squared over R. 213 00:09:32.559 --> 00:09:35.279 Same thing, just rearranged using Ohm's law. 214 00:09:35.519 --> 00:09:38.559 Why is knowing the power important? Because components have limits. 215 00:09:38.600 --> 00:09:41.960 Every resistor, every chip has a maximum power rating. Exceed 216 00:09:42.000 --> 00:09:45.600 it and dot poof it burns out uh one poof 217 00:09:45.799 --> 00:09:49.320 definitely not. And the book has this great table of 218 00:09:49.360 --> 00:09:54.279 household appliance power like an electric kettle three thousand watts. 219 00:09:54.440 --> 00:09:55.759 Whoa yeah, and. 220 00:09:55.679 --> 00:09:57.960 That's why you don't see battery powered kettles. Right a 221 00:09:58.000 --> 00:10:00.519 little AA battery you just can't pump out that kind power. 222 00:10:01.080 --> 00:10:02.480 It's theory meeting. 223 00:10:02.240 --> 00:10:05.559 Reality makes total sense. Okay, So quick recap on schematics, 224 00:10:05.559 --> 00:10:07.039 then the diagrams. 225 00:10:07.120 --> 00:10:10.039 Yeah, worth repeating rule one positive voltage usually up top, 226 00:10:10.600 --> 00:10:12.879 rule two, action flows left or right? 227 00:10:13.039 --> 00:10:13.360 Got it. 228 00:10:13.679 --> 00:10:16.879 Component names are systematic b one for battery one, are 229 00:10:16.960 --> 00:10:19.240 one for resistor one, see one for capacitor one, and 230 00:10:19.240 --> 00:10:21.480 so on, and their values are written right there. It's 231 00:10:21.480 --> 00:10:22.240 a visual language. 232 00:10:22.279 --> 00:10:24.480 Okay. Feeling a bit more confident about the basics. Now, 233 00:10:24.639 --> 00:10:29.600 let's talk about something flashy, literally LEDs, light emitting dios. 234 00:10:29.679 --> 00:10:35.200 Ah, Yes, LEDs. Everyone loves blinky lights. They're delicate little things. 235 00:10:35.200 --> 00:10:35.720 Elected. 236 00:10:35.759 --> 00:10:38.679 How you cannot just connect an LED straight to a battery, 237 00:10:38.759 --> 00:10:41.200 Well you can, but only once. It'll blow instantly. 238 00:10:41.440 --> 00:10:41.759 Okay. 239 00:10:41.759 --> 00:10:45.000 What they need a specific limited amount of current? Too 240 00:10:45.080 --> 00:10:47.840 much and they burn out. So you always need a 241 00:10:47.879 --> 00:10:50.120 current limiting resistor in series with them. 242 00:10:50.480 --> 00:10:52.600 And how do you figure out the right resistor? Back 243 00:10:52.639 --> 00:10:53.240 to alms law? 244 00:10:53.440 --> 00:10:57.360 You got it? You need to know the LED's forward voltage. 245 00:10:57.360 --> 00:11:00.159 That's the voltage it uses up when it's on. For 246 00:11:00.159 --> 00:11:03.559 a typical red LED, maybe around two volts. Okay, you 247 00:11:03.600 --> 00:11:06.720 subtract that from your battery voltage and then use Ohm's 248 00:11:06.759 --> 00:11:10.120 law r v A guy to calculate the resistor value 249 00:11:10.159 --> 00:11:11.399 needed to limit the current. 250 00:11:11.600 --> 00:11:13.320 How much current do they typically need? 251 00:11:13.639 --> 00:11:16.279 Usually somewhere between ten and twenty million ams is good 252 00:11:16.279 --> 00:11:19.080 for brightness. Just check the data sheets so you don't 253 00:11:19.080 --> 00:11:21.679 exceed its maximum rating, often around twenty five na. 254 00:11:21.919 --> 00:11:25.159 Right, Okay, here's a mistake I bit people make. Can 255 00:11:25.200 --> 00:11:28.440 you wire up like five LEDs in parallel and just 256 00:11:28.559 --> 00:11:30.399 use one resistor for all of them? 257 00:11:30.519 --> 00:11:32.759 Ah, the classic parallel LAED trap. 258 00:11:32.799 --> 00:11:35.320 No, definitely don't do that when it seems efficient. 259 00:11:34.960 --> 00:11:38.120 Because LEDs aren't perfectly identical. One will always have a 260 00:11:38.120 --> 00:11:40.759 slightly lower forward voltage than the others. That one will 261 00:11:40.759 --> 00:11:43.200 hog most of the current and poof, then the next 262 00:11:43.240 --> 00:11:45.679 one goes and so on cascade failure. 263 00:11:46.159 --> 00:11:47.720 Yikes. So the rule is. 264 00:11:48.039 --> 00:11:51.879 Always, always use a separate series resistor for each individual 265 00:11:52.000 --> 00:11:54.399 LED or series string of LEDs every time. 266 00:11:54.559 --> 00:11:56.799 No exceptions, got it. So LEDs aren't just little red 267 00:11:56.799 --> 00:11:57.639 indicator lights. 268 00:11:57.519 --> 00:11:59.960 Right, Oh gosh, no, they come in every color. Imagine 269 00:12:00.279 --> 00:12:04.519 different shape sizes, brightness levels, that's luminous intensity. You even 270 00:12:04.519 --> 00:12:06.080 get RGB LED's. 271 00:12:05.840 --> 00:12:07.159 Red, green, blue, yep. 272 00:12:07.519 --> 00:12:09.799 Combine those three in one package and you can mix 273 00:12:09.840 --> 00:12:11.000 basically any color you want. 274 00:12:11.159 --> 00:12:13.759 Cool and what about light we can't see. 275 00:12:13.600 --> 00:12:17.519 Right, infra red LEDs. Ir LEDs like in your TV 276 00:12:17.639 --> 00:12:22.320 remote and UV ultramolet LEDs use for things like curing 277 00:12:22.440 --> 00:12:24.759 resins or spotting counterfeit money. 278 00:12:24.799 --> 00:12:28.039 What about really bright LEDs like for lighting. 279 00:12:27.919 --> 00:12:30.519 High power LEDs. Yeah, they're a different beasts. They generate 280 00:12:30.559 --> 00:12:32.759 a lot of heat, so they absolutely need heat sinks, 281 00:12:33.200 --> 00:12:35.519 and you don't usually power them with just a resistor. 282 00:12:36.080 --> 00:12:39.720 Use a constant current driver circuit, often based on an 283 00:12:39.919 --> 00:12:42.200 IC like the LM three seventeen, and make sure the 284 00:12:42.279 --> 00:12:45.559 LED gets the exact current it needs regardless of voltage changes. 285 00:12:45.720 --> 00:12:49.240 Use more complex a little yeah, but necessary for those 286 00:12:49.320 --> 00:12:51.720 high power ones. And if you're using a bunch of 287 00:12:51.840 --> 00:12:55.759 LEDs together, the book suggests actually measuring their forward voltage 288 00:12:55.759 --> 00:12:59.200 first with a multimeter and a variable resistor helps keep 289 00:12:59.240 --> 00:13:01.080 the brightness consist. 290 00:13:00.679 --> 00:13:05.320 Smart okay, project time. How about making LED's flash perfect application? 291 00:13:05.720 --> 00:13:09.440 The book introduces a super useful little chip, the five 292 00:13:09.480 --> 00:13:10.679 to five to five timer. 293 00:13:10.720 --> 00:13:13.120 I see the five five to five heard of it? 294 00:13:13.399 --> 00:13:17.399 Versatile, incredibly versatile, great for making LED's flash, making sounds, 295 00:13:17.519 --> 00:13:20.759 timing things. Just a brilliant little building block. You can 296 00:13:20.799 --> 00:13:23.279 whip up an LED flasher circuit on a bread board 297 00:13:23.320 --> 00:13:23.960 in minute. 298 00:13:24.080 --> 00:13:25.960 Cool that breadboards aren't permanent, right. 299 00:13:25.919 --> 00:13:28.759 Wires fall out exactly, great for testing, but not for 300 00:13:28.799 --> 00:13:31.000 a finished project. That's where strip board comes out. 301 00:13:31.000 --> 00:13:32.080 Strip Board, Okay, what's that? 302 00:13:32.279 --> 00:13:34.720 It's like a general purpose circuit board. It's got parallel 303 00:13:34.759 --> 00:13:37.600 strips of copper running along one side. You solder your 304 00:13:37.600 --> 00:13:40.159 components onto it, making connections via the strips. 305 00:13:40.399 --> 00:13:43.279 So more permanent than breadboard, much more robust. 306 00:13:43.799 --> 00:13:46.000 But you have to plan your layout a bit more carefully. 307 00:13:46.200 --> 00:13:48.679 You figure out where components go based on your schematic. 308 00:13:49.159 --> 00:13:50.559 And you mentioned cutting tracks. 309 00:13:50.840 --> 00:13:53.039 Yeah, sometimes you need to break a copper strip to 310 00:13:53.200 --> 00:13:55.559 stop a connection. You just use a small drill bit 311 00:13:55.799 --> 00:13:57.720 twist it by hand to cut the track. 312 00:13:57.919 --> 00:14:00.399 Okay, so how do you build that five fifty five 313 00:14:00.480 --> 00:14:01.440 flasher on strip board? 314 00:14:01.559 --> 00:14:03.840 You'd plan the layout, maybe, sketch it out, cut the 315 00:14:03.840 --> 00:14:07.879 board to size, make any track cuts needed. Then solder 316 00:14:07.879 --> 00:14:11.279 things in order. Start with the lowest components like wirelings to. 317 00:14:11.360 --> 00:14:13.799 Resistors so they don't get in the way later, right. 318 00:14:14.000 --> 00:14:18.960 Then maybe the icy socket, then taller things like capacitors, LEDs, connectors, 319 00:14:19.000 --> 00:14:23.159 and always always check carefully for solder bridges or mistakes 320 00:14:23.200 --> 00:14:24.279 before powering it up. 321 00:14:25.000 --> 00:14:28.559 Good habit. Okay, a more advanced LED project. 322 00:14:28.279 --> 00:14:31.559 Slot cars, Yeah, this one's fun. Hack a toy slot 323 00:14:31.600 --> 00:14:33.279 car to add working headlights and brake light. 324 00:14:33.399 --> 00:14:34.759 Brake lights. How do they work? 325 00:14:35.120 --> 00:14:38.559 It uses a capacitor that's an electronic component that stores charge. 326 00:14:38.639 --> 00:14:41.799 When the car has power, A diode charges the capacitor. Okay, 327 00:14:41.799 --> 00:14:43.639 when you let off the power, the track goes dead, 328 00:14:43.919 --> 00:14:47.440 but the charge capacitor then discharges through the brake light LEDs, 329 00:14:47.519 --> 00:14:48.879 keeping them lit for a second or two. 330 00:14:49.120 --> 00:14:52.600 That's clever, like regenerative breaking, but just for lights kind of. 331 00:14:52.679 --> 00:14:54.960 It's a neat little circuit shows how you can combine 332 00:14:55.000 --> 00:14:58.159 components for cool effects, and LEDs are perfect because they're 333 00:14:58.200 --> 00:14:59.320 small enough to fit in the car. 334 00:14:59.519 --> 00:15:03.600 Right, Okay, powering these creations, every project needs juice. 335 00:15:03.840 --> 00:15:06.399 Batteries seem obvious obvious, but there's a bit to consider. 336 00:15:06.919 --> 00:15:10.320 Key things are capacity. That's them millionamp hours basically how 337 00:15:10.399 --> 00:15:14.120 much energy it stores and it's maximum discharge rate. How 338 00:15:14.159 --> 00:15:17.600 fast can you pull power out? Batteries have internal resistance. 339 00:15:18.120 --> 00:15:19.559 Try to draw too much current and. 340 00:15:19.519 --> 00:15:21.440 They get hot, sometimes dangerously hot. 341 00:15:21.480 --> 00:15:25.360 You mentioned especially Leipo batteries. Yeah, need respect, but the 342 00:15:25.399 --> 00:15:30.399 book has this great hacking spirit advice. Sometimes just try it. 343 00:15:30.440 --> 00:15:32.120 See how hot it gets, how long it lasts? 344 00:15:32.200 --> 00:15:35.720 Learned by doing within reason Hopefully. What if one battery 345 00:15:35.759 --> 00:15:37.360 isn't enough voltage. 346 00:15:36.879 --> 00:15:39.799 Easy put them in series in a battery holder end 347 00:15:39.799 --> 00:15:43.480 to end their voltages add up. Just remember rechargeable cells 348 00:15:43.559 --> 00:15:47.200 often have slightly lower voltage than single use ones. Like 349 00:15:47.320 --> 00:15:49.799 a rechargeable AA is one point two V not one 350 00:15:49.799 --> 00:15:50.519 point five V. 351 00:15:50.679 --> 00:15:52.799 Good point. And there are different types of batteries. 352 00:15:52.480 --> 00:15:56.039 Right loads single use you've got your standard alkaline, lithium, 353 00:15:56.120 --> 00:16:00.639 higher energy density, zinc, air, silver oxide, and recharge. Common 354 00:16:00.639 --> 00:16:05.840 ones are NIMMH nickel metal hydride, LiPo lithium polymer very 355 00:16:05.879 --> 00:16:09.120 popular now, and sealed lead acid like in cars or 356 00:16:09.159 --> 00:16:13.279 backup systems. Rosen cons quick rundown. NIMMH is decent costwaight, 357 00:16:13.399 --> 00:16:16.720 but self discharges kind of quickly. LiPo is light, lots 358 00:16:16.720 --> 00:16:20.360 of power for its size, low self discharge, but can 359 00:16:20.399 --> 00:16:24.080 be fiery if mistreated and of care definitely sealed. Lead 360 00:16:24.120 --> 00:16:27.679 acid is heavy and bulky, but cheap, tough, and pretty 361 00:16:27.720 --> 00:16:29.879 forgiving if you accidentally overcharge it a. 362 00:16:29.799 --> 00:16:33.519 Bit okay, charging them sounds like another potential pitfall. What's 363 00:16:33.559 --> 00:16:34.159 the sea rate? 364 00:16:34.399 --> 00:16:37.159 Sea just stands for capacity, So a one C charge 365 00:16:37.200 --> 00:16:39.480 rate means you're charging it at a current equal to 366 00:16:39.519 --> 00:16:42.919 its capacity, theoretically charging it in one hour point one 367 00:16:43.000 --> 00:16:46.320 CE means charging at one tenth capacity taking about ten hours. 368 00:16:46.519 --> 00:16:48.320 And you mentioned overcharging is bad. 369 00:16:48.279 --> 00:16:52.240 Very bad for most types, causes damage, overheating LiPo especially 370 00:16:52.279 --> 00:16:55.399 doesn't like it, and over discharging running them completely flat 371 00:16:55.480 --> 00:16:56.960 is also bad for their lifespan. 372 00:16:57.159 --> 00:16:58.159 So trickle charging. 373 00:16:58.399 --> 00:17:02.440 Trickle charging is just a very slow, gentle charge safer 374 00:17:02.480 --> 00:17:07.640 for some types, helps avoid overcharging. Many modern batteries, especially lipos, 375 00:17:07.680 --> 00:17:10.000 have protection circuits built in now, which helps. 376 00:17:10.079 --> 00:17:11.519 Do we chargeables last forever? 377 00:17:11.880 --> 00:17:15.240 Nope? They have a limited number of charge discharge cycles, 378 00:17:15.599 --> 00:17:18.200 maybe five hundred times give or take, before they really 379 00:17:18.200 --> 00:17:20.960 start to lose capacity. Something to keep in mind. 380 00:17:21.039 --> 00:17:22.480 How do you charge specific types? 381 00:17:22.519 --> 00:17:25.079 Then the MH You can trickle charge simply with a 382 00:17:25.119 --> 00:17:28.200 power supply and a resistor. Calculate the right resistor using 383 00:17:28.279 --> 00:17:31.799 Ohm's law. Fast charging needs a proper charger let acid 384 00:17:32.079 --> 00:17:35.839 less fussy can trickle charge or charge faster with a 385 00:17:35.880 --> 00:17:38.720 fixed voltage like fourteen point four V for a twelve 386 00:17:38.759 --> 00:17:40.599 V battery, but with current. 387 00:17:40.440 --> 00:17:43.279 Limiting and lipos the tricky ones. 388 00:17:43.160 --> 00:17:46.480 Very specific needs a fixed voltage exactly four point two 389 00:17:46.559 --> 00:17:49.599 V per cell and limited current. Crucially, you cannot charge 390 00:17:49.640 --> 00:17:52.440 multiple LICO cells and series with a simple charger. You 391 00:17:52.480 --> 00:17:55.200 need to charge each cell individually or use a balanced 392 00:17:55.279 --> 00:17:56.920 charger and no trickle charging. 393 00:17:56.960 --> 00:18:00.000 Wow, okay, good to know. What about using old phone batteries? 394 00:18:00.039 --> 00:18:01.240 People have those lying around? 395 00:18:01.440 --> 00:18:05.160 Yeah? Great hack. You can often salvage and reuse old 396 00:18:05.240 --> 00:18:07.839 cell phone lip bo batteries. Just be a little careful. 397 00:18:07.920 --> 00:18:10.559 Older ones might not have the same safety cutoff circuits 398 00:18:10.559 --> 00:18:13.039 as new ones. Test them cautiously right now. 399 00:18:13.319 --> 00:18:16.440 Batteries don't maintain constant voltage, do they. They droop as. 400 00:18:16.279 --> 00:18:20.160 They discharge exactly, and that voltage drop can cause problems 401 00:18:20.160 --> 00:18:23.160