1 00:00:00,080 --> 00:00:03,181 You’ve no doubt seen plenty of fluorescent lights, 2 00:00:03,181 --> 00:00:05,683 but have you ever seen one like this? 3 00:00:05,683 --> 00:00:08,562 It may not seem all that strange at first glance, 4 00:00:08,562 --> 00:00:13,163 after all there have been plenty of weird fluorescent lamp designs over the years. 5 00:00:13,163 --> 00:00:16,607 But this one’s missing a pretty crucial part: 6 00:00:16,607 --> 00:00:18,964 the electrical connections. 7 00:00:18,964 --> 00:00:24,934 Your typical fluorescent tube has little wires attached to pins which stick out of the glass at each end, 8 00:00:24,934 --> 00:00:28,606 and they connect to electrodes inside the tube. 9 00:00:28,606 --> 00:00:33,869 Those wires are then connected to a ballast and starter which together place a voltage on  the electrodes 10 00:00:33,869 --> 00:00:37,654 to pump electricity through the lamp which makes it glow. 11 00:00:37,654 --> 00:00:41,725 But this… this is just a glass tube. 12 00:00:42,689 --> 00:00:44,459 How’s that supposed to work? 13 00:00:44,858 --> 00:00:47,228 Well, with these. 14 00:00:47,228 --> 00:00:51,341 The tube is designed to be held in place by a pair of… 15 00:00:51,341 --> 00:00:53,752 let’s call them electromagnets. 16 00:00:53,752 --> 00:00:56,809 That’s not exactly the right word which will become clear in a moment 17 00:00:56,809 --> 00:01:03,358 but each one of them is formed by wrapping a wire around a ferrite core several times. 18 00:01:03,358 --> 00:01:06,521 With the help of electronics inside this driver unit, 19 00:01:06,521 --> 00:01:09,966 a high-frequency alternating current is sent through the wires 20 00:01:09,966 --> 00:01:17,173 which then causes a magnetic field to repeatedly form, collapse, and form again inside the ferrite cores. 21 00:01:17,605 --> 00:01:20,610 Now, if you know a little bit about power transformers, 22 00:01:20,610 --> 00:01:26,395 then if we take the tube out of the picture for a moment and look at a core by itself, 23 00:01:26,395 --> 00:01:33,228 then what we’re looking at appears to be a toroidal power transformer that somebody forgot to finish. 24 00:01:33,228 --> 00:01:39,189 See, usually we’d have at least two coils of wire wrapped around one of these cores. 25 00:01:39,189 --> 00:01:44,218 When we run alternating current through the first coil of wire, called the primary winding, 26 00:01:44,218 --> 00:01:48,369 it will induce a rapidly changing magnetic field through the core 27 00:01:48,369 --> 00:01:54,041 which in turn induces a voltage on the other coil of wire known as the secondary winding. 28 00:01:54,407 --> 00:01:58,570 When that secondary winding is part of a circuit, current will flow 29 00:01:58,570 --> 00:02:07,039 and the upshot is that energy is transferred from the primary winding, through the core, and into the secondary winding. 30 00:02:07,039 --> 00:02:11,593 We often do this because the secondary winding will produce a different voltage 31 00:02:11,593 --> 00:02:16,785 when it has a different number of turns around the core compared to the primary. 32 00:02:16,785 --> 00:02:20,844 But here, there isn’t a secondary winding! 33 00:02:20,844 --> 00:02:22,781 It just doesn’t exist. 34 00:02:22,781 --> 00:02:25,936 That is, until I put the tube back. 35 00:02:25,936 --> 00:02:31,415 This lamp isn’t a literal wire, of course, but once I have it enclosed by the core 36 00:02:31,415 --> 00:02:38,357 it does indeed form a loop in the exact same way a single turn secondary winding would. 37 00:02:38,357 --> 00:02:47,499 It looks a little strange because it’s going way over there before looping back to the core, but that’s what it is. 38 00:02:47,499 --> 00:02:53,863 Now, because this lamp is so large, we need a second core positioned on the other end of the tube, 39 00:02:53,863 --> 00:02:57,526 but they’re wired together and so act as one. 40 00:02:57,526 --> 00:03:03,732 When the alternating current being sent through the wires by this driver unit induces magnetic fields in the cores, 41 00:03:03,732 --> 00:03:08,510 those fields then induce a voltage  inside the fluorescent tube. 42 00:03:08,510 --> 00:03:15,518 And, because it’s formed in a loop, that results in current flow which causes the lamp to light. 43 00:03:15,518 --> 00:03:19,555 For that reason, this is known as an  induction lamp. 44 00:03:19,555 --> 00:03:25,477 The actual light it produces is the result of the exact same principle as an ordinary fluorescent tube: 45 00:03:25,477 --> 00:03:33,415 a low-pressure arc discharge is produced by passing current through an ionized mixture of mercury vapor and a noble gas such as argon, 46 00:03:33,415 --> 00:03:38,279 and as electrons collide with the mercury atoms the mercury emits ultraviolet light 47 00:03:38,279 --> 00:03:42,725 which is then converted to visible light by the phosphors coating the glass. 48 00:03:42,725 --> 00:03:48,884 But rather than use electrodes  reaching inside the tube in order to pass current through the gas, 49 00:03:48,884 --> 00:03:54,080 current flow is generated  externally via electromagnetic induction. 50 00:03:54,640 --> 00:03:56,458 Why would we want that? 51 00:03:56,458 --> 00:03:59,120 Well first, it’s pretty cool! 52 00:03:59,120 --> 00:04:07,920 But also this particular lamp has a power rating of 200W and a light output in the neighborhood of 16,000 lumens. 53 00:04:07,920 --> 00:04:15,357 That is unusually powerful and bright for a fluorescent lamp,  especially given its relatively small size. 54 00:04:15,357 --> 00:04:22,731 But brightness, power, and coolness weren’t really the main reasons these appeared - operating life was. 55 00:04:22,731 --> 00:04:28,185 Getting rid of the electrodes would mean getting rid of the weak point of the fluorescent lamp. 56 00:04:28,185 --> 00:04:34,803 In a conventional tube, the electrodes slowly  wear out in a process known as sputtering. 57 00:04:34,803 --> 00:04:40,952 This happens the most at lamp start-up, but sputtering still happens throughout continued operation. 58 00:04:40,952 --> 00:04:44,696 Over time this causes the ends of the tube to darken - 59 00:04:44,696 --> 00:04:53,301 the dark spots are the material which used to be the electrodes, but as it sputters off it becomes deposited on the glass. 60 00:04:53,301 --> 00:04:58,962 That reduces light output slightly but the bigger problem is that as they wear away 61 00:04:58,962 --> 00:05:03,022 the electrodes lose their ability to emit electrons. 62 00:05:03,022 --> 00:05:08,794 That makes it more difficult for the ballast and starter to initiate the arc discharge across the tube, 63 00:05:08,794 --> 00:05:15,956 and eventually they will wear to the point the tube is no longer able to start and the lamp has failed. 64 00:05:15,956 --> 00:05:21,042 As the technology developed we got pretty good at making electrodes which could last a good while, 65 00:05:21,042 --> 00:05:26,636 and fluorescent lamps would  typically have a rated life of 10,000 hours. 66 00:05:26,636 --> 00:05:33,140 But if we could do without the electrodes,  the lamp could in theory last forever. 67 00:05:33,140 --> 00:05:37,380 And, well, that’s the point of this technology. 68 00:05:37,380 --> 00:05:42,887 There’s nothing to the lamp but a phosphor-coated tube filled with some argon gas 69 00:05:42,887 --> 00:05:47,740 and a pellet of mercury amalgam chilling in this little glass appendix. 70 00:05:47,740 --> 00:05:55,907 It has no electrodes to wear out and  this means the tube itself has a theoretically unlimited lifespan. 71 00:05:55,907 --> 00:06:01,412 Nothing truly lasts forever, of course, and due to phosphor wear and mercury absorption 72 00:06:01,412 --> 00:06:04,281 these will lose light output over time, 73 00:06:04,281 --> 00:06:12,375 but these lamps have a rated lifespan of 100,000 hours - a tenfold increase over conventional tubes. 74 00:06:12,375 --> 00:06:20,144 Operating dusk-to-dawn, that would mean this should last nearly 23 years before requiring replacement. 75 00:06:20,144 --> 00:06:28,847 Now, obviously, that’s a pretty phenomenal lifespan and so it might be surprising how uncommon this technology is. 76 00:06:28,847 --> 00:06:32,243 I mean, there’s not a whole lot to this thing 77 00:06:32,243 --> 00:06:38,683 and it operates on the fundamentals of electromagnetism that have been understood since the 19th century. 78 00:06:38,683 --> 00:06:45,983 Sure enough, electrodeless lamps which operated via induction had been demonstrated many, many times in the past. 79 00:06:45,983 --> 00:06:49,297 Nikola Tesla was playing with it because of course he was. 80 00:06:49,297 --> 00:06:55,684 But a practical and effective application of the technology was surprisingly elusive. 81 00:06:55,684 --> 00:07:01,865 It wasn’t until 1967 that John Anderson filed a patent for a lamp like this one, 82 00:07:01,865 --> 00:07:08,967 and then it took until 1990 for it to actually be commercialized into a finished product. 83 00:07:08,967 --> 00:07:11,179 What took so long? 84 00:07:11,179 --> 00:07:16,174 Well, despite how simple the overall  idea is on the surface, 85 00:07:16,174 --> 00:07:23,694 it turns out there were a LOT of different problems that needed solving before this could actually become a reality. 86 00:07:23,694 --> 00:07:32,787 For one thing, inducing current flow in a loop of gas, even if it is conductive, is a lot harder than a solid metal wire. 87 00:07:32,787 --> 00:07:40,757 To sustain the arc discharge in the tube, the magnetic field generated by the cores has to switch back and forth very a lot, 88 00:07:40,757 --> 00:07:45,712 so the frequency at which this thing operates needed to be very high. 89 00:07:45,712 --> 00:07:50,788 You’ll notice the patent shows the driver as “converter to radio frequency” 90 00:07:50,788 --> 00:07:56,132 and Anderson lists a preferred frequency range of 100 to 500 kilocycles. 91 00:07:56,132 --> 00:08:00,257 That’s almost reaching the AM radio broadcast band. 92 00:08:00,257 --> 00:08:06,901 By 1967 it was relatively trivial to produce high-powered oscillators which ran at that frequency, 93 00:08:06,901 --> 00:08:09,395 but that wasn’t the main issue. 94 00:08:09,395 --> 00:08:12,032 Because of the required high frequency, 95 00:08:12,032 --> 00:08:19,486 wrapping wire around an ordinary iron core as found in most power transformers wasn’t feasible. 96 00:08:19,486 --> 00:08:26,512 At those frequencies, the eddy currents which form inside the cores would cause it to get extremely hot. 97 00:08:26,512 --> 00:08:30,272 That’s the mechanism by which induction cooktops work. 98 00:08:30,272 --> 00:08:34,853 But the problem is, that would both limit  the efficiency of the power coupling 99 00:08:34,853 --> 00:08:41,932 and how much power you could feasibly transfer into the tube before the cores started to melt. 100 00:08:41,932 --> 00:08:48,323 This meant ferrite compounds, which are extremely magnetically permeable but not electrically conductive 101 00:08:48,323 --> 00:08:51,656 and therefore don’t form eddy currents inside, 102 00:08:51,656 --> 00:08:55,538 were required for high-frequency power coupling. 103 00:08:55,538 --> 00:09:03,042 They weren’t invented until the 1930’s and even though they were fairly common by the time Anderson filed his patent, 104 00:09:03,042 --> 00:09:05,953 ferrite was still an expensive material. 105 00:09:05,953 --> 00:09:11,260 In fact, that’s the main reason this lamp gets narrower where the cores attach: 106 00:09:11,260 --> 00:09:16,106 making the tube diameter  smaller requires less material in the cores. 107 00:09:16,106 --> 00:09:19,211 But here’s where the story gets a little weird. 108 00:09:19,211 --> 00:09:25,860 Although this patent is nearly a spot-on description of  this lamp both in form and function, 109 00:09:25,860 --> 00:09:30,960 the first commercial products using the technology were very different from this. 110 00:09:31,520 --> 00:09:37,291 The QL line from Philips was the first commercial induction lamp and they looked… 111 00:09:37,291 --> 00:09:41,025 pretty much like an ordinary incandescent light bulb. 112 00:09:41,025 --> 00:09:46,701 They weren’t - they were in fact fluorescent lamps which worked by induction similar to this. 113 00:09:46,701 --> 00:09:53,923 But compared to this tube and its external cores, they were constructed inside-out. 114 00:09:53,923 --> 00:10:00,182 I don’t have one to show you, but thanks to a donation to the channel from Jeff, a long-time Patreon member, 115 00:10:00,182 --> 00:10:05,561 I do have this variation which was manufactured by GE. 116 00:10:05,561 --> 00:10:12,418 This Genura lamp was released in 1994 and it is designed to replace a reflector flood bulb 117 00:10:12,418 --> 00:10:17,465 but it works on the same basic principle to the original Philips QL lamps. 118 00:10:17,465 --> 00:10:21,794 Here, the discharge tube isn’t so much a tube as it is... 119 00:10:21,794 --> 00:10:23,577 a vessel. 120 00:10:23,577 --> 00:10:28,823 And a single coil, once again in the form of a wire wrapped around a  ferrite core, 121 00:10:28,823 --> 00:10:35,162 protrudes from the base of the lamp into a hollowed-out section of the glass vessel. 122 00:10:35,162 --> 00:10:41,071 This evacuation stem holds the pellet of mercury amalgam which is required to produce ultraviolet light 123 00:10:41,071 --> 00:10:45,178 and it rests inside the ferrite core when assembled. 124 00:10:45,178 --> 00:10:51,399 An oscillator circuit in the base of the bulb sends high-frequency pulses through the wire wrapped around the ferrite core 125 00:10:51,399 --> 00:10:56,310 which in turn creates a rapidly fluctuating magnetic field around it. 126 00:10:56,310 --> 00:11:00,976 That field reaches well inside the discharge vessel. 127 00:11:00,976 --> 00:11:06,086 As the field changes in intensity, current flows through the gas inside, 128 00:11:06,086 --> 00:11:09,681 and our desired mercury discharge occurs. 129 00:11:09,681 --> 00:11:18,552 In this lamp design, the single coil protruding into the vessel produces a magnetic field in a toroidal shape around its perimeter. 130 00:11:18,552 --> 00:11:23,302 That’s why the QL lamps from Philips look a lot like an ordinary light bulb. 131 00:11:23,302 --> 00:11:31,855 It’s not a linear discharge running through a tube but more of a fuzzy donut of ultraviolet light surrounding the induction coil, 132 00:11:31,855 --> 00:11:35,933 which a bulb-shape happens to encapsulate quite well. 133 00:11:35,933 --> 00:11:39,626 The phosphors on the glass convert the UV to visible light 134 00:11:39,626 --> 00:11:45,946 and the result is a compact yet very bright light source with an extremely long life. 135 00:11:45,946 --> 00:11:52,875 The original QL lamps ran at 85 watts and had a rated life of 100,000 hours. 136 00:11:52,875 --> 00:12:02,640 Now, this GE lamp isn’t quite so optimistic but that’s likely down to the fact that its drive electronics are built into the lamp itself. 137 00:12:02,720 --> 00:12:05,842 This was sold as a drop-in replacement light bulb, 138 00:12:05,842 --> 00:12:09,067 so everything had to get crammed into here. 139 00:12:09,067 --> 00:12:12,686 And since these are generally  operated with the base facing up, 140 00:12:12,686 --> 00:12:17,138 heat from the discharge would rise right into the electronic components 141 00:12:17,138 --> 00:12:21,070 which shortens their operating life, especially capacitors. 142 00:12:21,070 --> 00:12:25,827 The QL line from Philips used an external driver muck like this thing does 143 00:12:25,827 --> 00:12:29,840 and the lamp itself was little more than a glass orb on a stick. 144 00:12:30,400 --> 00:12:33,671 Still, it wasn't quite as simple as it looks. 145 00:12:33,671 --> 00:12:39,243 Because the induction coil was shoved up the middle of the lamp, it gets pretty hot - 146 00:12:39,243 --> 00:12:45,107 particularly in the case of the QL lamps which operated at 85 watts. 147 00:12:45,107 --> 00:12:49,607 This was a problem because as the  ferrite material increases in temperature, 148 00:12:49,607 --> 00:12:55,671 its magnetic permeability decreases which  limited the strength of the magnetic fields it can produce 149 00:12:55,671 --> 00:12:59,699 and thus the amount of power it can send into the gas discharge. 150 00:12:59,699 --> 00:13:04,124 That reduces both brightness and energy efficiency. 151 00:13:04,124 --> 00:13:10,544 Philips solved this by incorporating heat-conducting material into the design of the ferrite core’s stem, 152 00:13:10,544 --> 00:13:14,419 which by the way they referred to as the antenna. 153 00:13:14,419 --> 00:13:19,588 From what I can tell looking at patents, GE didn’t solve this at all, 154 00:13:19,588 --> 00:13:26,160 but since the lamp only operates at 23 watts  the induction coil probably never got hot enough to matter. 155 00:13:26,468 --> 00:13:33,120 But another issue with the single-coil designs is that  it require an even higher frequency to function:   156 00:13:33,120 --> 00:13:36,154 around 2.5 megahertz. 157 00:13:36,154 --> 00:13:43,622 And because these are operating at radio frequencies and pumping dozens of watts or more into the discharge vessel, 158 00:13:43,622 --> 00:13:47,779 well radio frequency interference was a significant problem. 159 00:13:47,779 --> 00:13:55,115 To try and help solve it, the glass is coated with a transparent yet conductive material, such as indium tin oxide, 160 00:13:55,115 --> 00:13:58,896 which absorbs radio frequency energy and  keeps it from escaping. 161 00:13:58,896 --> 00:14:07,279 And in this lamp, the underside of the discharge vessel also has a metal shield which was bonded to this copper ribbon 162 00:14:07,279 --> 00:14:11,048 that allows the absorbed energy to return to the circuit ground. 163 00:14:11,048 --> 00:14:17,521 But, it’s clear that GE at least wasn’t making the strongest promises about its effectiveness. 164 00:14:17,521 --> 00:14:24,399 They warn specifically against using these on boats as they could disrupt maritime communications. 165 00:14:24,399 --> 00:14:28,927 And, uh, given that they provided a phone number for interference complaints... 166 00:14:28,927 --> 00:14:32,696 well I think it’s safe to say this was very much a beta test. 167 00:14:32,696 --> 00:14:39,960 Now, it might seem a little odd that  the basic idea for this later design was patented in 1967 168 00:14:39,960 --> 00:14:47,930 yet induction lighting didn’t get commercialized until after Philips and GE released their single-coil designs. 169 00:14:47,930 --> 00:14:53,176 But it might make more sense if you consider that these external-coil lamps... 170 00:14:53,176 --> 00:14:56,782 really aren't that different from conventional fluorescent tubes. 171 00:14:56,782 --> 00:15:06,714 In fact, many lower-power versions of this design incorporated circular tubes which look a whole awful lot like a standard circular fluorescent lamp. 172 00:15:06,714 --> 00:15:13,133 They did offer higher light outputs, but the form was still very familiar. 173 00:15:13,133 --> 00:15:23,591 The fact that neither the QL lamp nor this Genura lamp look anything like a fluorescent tube is probably why the technology was first commercialized like this. 174 00:15:23,591 --> 00:15:25,783 Consider the GE bulb: 175 00:15:25,783 --> 00:15:36,258 the resulting discharge inside this vessel produces a compact but powerful ring of UV light just under a relatively flat piece of glass. 176 00:15:36,258 --> 00:15:41,462 This meant fluorescent technology could not only mimic the appearance of an incandescent reflector 177 00:15:41,462 --> 00:15:49,040 much more faithfully than sticking a coiled tube inside a  fake bulb but it was also much more effective. 178 00:15:49,600 --> 00:15:58,840 This flavor of induction technology was able to create much more powerful yet also compact light sources than a linear fluorescent tube 179 00:15:58,840 --> 00:16:02,715 while still offering similar energy-efficiency. 180 00:16:02,715 --> 00:16:07,771 That was compelling enough on its own to  pursue not only for aesthetic purposes 181 00:16:07,771 --> 00:16:14,335 but because it allowed the use of fixtures with optical systems that produced much more directional light. 182 00:16:15,405 --> 00:16:18,480 To a point at least - I’ll touch on that more in a bit. 183 00:16:19,040 --> 00:16:23,680 Induction technology also solved one of  fluorescent lighting’s little annoyances: 184 00:16:23,680 --> 00:16:25,576 a slow warm-up. 185 00:16:25,576 --> 00:16:31,388 High-efficiency fluorescent tubes in particular only produce a fraction of their light output at first 186 00:16:31,388 --> 00:16:37,479 due to lower vapor pressure when cold and thus they can take several minutes to warm up. 187 00:16:37,479 --> 00:16:42,475 This lamp also starts with a lower  vapor pressure and thus reduced light output, 188 00:16:42,475 --> 00:16:45,429 but the warmup time is just a few seconds. 189 00:16:45,429 --> 00:16:52,135 And the large external-coil lamp is similarly quick - it’s at full brightness in only 10 seconds. 190 00:16:52,135 --> 00:16:59,841 You can actually observe the mercury discharge migrating away from the amalgam pellet as the tube heats up and the pressure builds. 191 00:16:59,841 --> 00:17:03,153 But… well, that was at room temperature, 192 00:17:03,153 --> 00:17:06,176 and these lamps were sold to go outdoors. 193 00:17:06,176 --> 00:17:11,714 In fact street lighting is one of the most likely  places you’re going to find these in the wild. 194 00:17:11,714 --> 00:17:15,818 And I live where the outside air sometimes gets colder than a freezer, 195 00:17:15,818 --> 00:17:22,620 so I put this whole thing inside a freezer overnight to see how quickly it would warm up from truly cold. 196 00:17:22,620 --> 00:17:28,258 The lamp had no issues starting but, like most fluorescent lights in this temperature, 197 00:17:28,258 --> 00:17:35,455 the mercury was barely contributing anything and we could see the purple glow of the argon starter gas. 198 00:17:35,455 --> 00:17:41,566 Interestingly it initially did the same thing  where the light output seems to grow from the mercury pellet, 199 00:17:41,566 --> 00:17:48,170 but before long that bright spot disappeared and it all averaged out to a very dull grey. 200 00:17:48,170 --> 00:17:55,880 It took about 10 minutes to attain full brightness so it looks like cold-weather performance is only improved slightly. 201 00:17:55,880 --> 00:17:58,743 But at least it had no trouble starting! 202 00:17:58,743 --> 00:18:03,609 Speaking of starting, well now it’s time to come clean here - 203 00:18:03,609 --> 00:18:08,578 I don’t really understand the mechanisms by which these lamps start. 204 00:18:08,578 --> 00:18:14,939 See, the gas mixture in these tubes isn’t electrically conductive until it’s ionized. 205 00:18:14,939 --> 00:18:23,437 The electrodes in a traditional fluorescent tube emit electrons when heated and/or when a sufficiently high voltage is placed across them, 206 00:18:23,437 --> 00:18:30,960 and those electrons collide with the gas molecules inside  and ionize them which causes dielectric breakdown. 207 00:18:31,520 --> 00:18:36,139 But with these, all we got is magnets. 208 00:18:36,139 --> 00:18:44,519 The 1967 patent mentions the use of electrodes in contact with the glass that, when a sufficiently high voltage is placed across them, 209 00:18:44,519 --> 00:18:49,560 will ionize enough gas inside the tube to initiate dielectric breakdown. 210 00:18:49,560 --> 00:18:53,564 But this device has no such electrodes. 211 00:18:53,564 --> 00:18:59,902 A later patent filed in 1995 describes this device nearly perfectly, 212 00:18:59,902 --> 00:19:08,159 and it even has a diagram which more clearly illustrates the rather confusing way the wires are wrapped around the two ferrite cores. 213 00:19:08,159 --> 00:19:17,441 But it also mentions a conductive strip in contact with the glass specifically for the purpose of creating ionization points for starting the lamp. 214 00:19:18,708 --> 00:19:22,103 But again, this lamp doesn’t have those. 215 00:19:22,103 --> 00:19:28,389 All the information I could find on how this lamp gets started was quite handwavey, 216 00:19:28,389 --> 00:19:36,264 but my best understanding is that the driver circuitry initially sends a much higher than usual voltage through the wires 217 00:19:36,264 --> 00:19:43,093 which produces a strong enough electric field that free electrons in the gas mixture are sort of thrown about, 218 00:19:43,093 --> 00:19:45,278 causing some ionization. 219 00:19:45,278 --> 00:19:51,180 Basically it’s the same way that fluorescent tubes can start glowing when you hold them near a Tesla coil. 220 00:19:51,180 --> 00:19:56,198 And once some of that gas is ionized the discharge across the tube can be completed 221 00:19:56,198 --> 00:20:00,051 after which the driver can switch to its normal operating voltage. 222 00:20:00,051 --> 00:20:05,882 That may also further explain why the internal core lamps were commercialized first. 223 00:20:05,882 --> 00:20:12,341 Based on readings of patents, it was initially thought  that a secondary winding would be needed on the ferrite core 224 00:20:12,341 --> 00:20:16,826 to produce a high voltage capable of initiating a glow discharge, 225 00:20:16,826 --> 00:20:23,981 but that feature seems to have gone away once it was decided to use the very high frequency found here. 226 00:20:23,981 --> 00:20:31,787 This patent filed in 1982 seems to suggest that simply by inducing the magnetic field at a frequency of 3 megahertz, 227 00:20:31,787 --> 00:20:37,869 a sufficiently strong electric field is produced  inside the vessel which can ionize the gas. 228 00:20:37,869 --> 00:20:43,280 But I still haven’t gotten a truly satisfactory answer,  here, and would welcome one in the comments! 229 00:20:43,840 --> 00:20:47,683 It might have something to do with the metal  mesh found here, 230 00:20:47,683 --> 00:20:55,298 and a closer look up the middle of this Genura’s discharge vessel shows a piece of wire at the top of the evacuation stem. 231 00:20:55,298 --> 00:20:58,764 But truthfully, I gave up trying to find an answer. 232 00:20:59,266 --> 00:21:07,025 So, with their extremely long operating life  and newfound applications for energy-efficient fluorescent lighting, 233 00:21:07,025 --> 00:21:10,961 it might seem strange that this technology is so obscure. 234 00:21:10,961 --> 00:21:15,209 I mean, today we have LEDs and this technology is obsolete 235 00:21:15,209 --> 00:21:24,140 but knowing that back in 1990 we had a lighting technology with a lifespan that essentially matches the best LEDs we have today, 236 00:21:24,140 --> 00:21:27,906 you would think it would have taken the world by storm. 237 00:21:27,906 --> 00:21:29,215 Yet it didn’t. 238 00:21:29,863 --> 00:21:30,926 Why? 239 00:21:30,926 --> 00:21:34,411 Was there another one of those light bulb conspiracies afoot? 240 00:21:34,411 --> 00:21:35,966 Yeah, no. 241 00:21:35,966 --> 00:21:42,319 See, here’s the thing - the tech is really cool and opens up some new possibilities, 242 00:21:42,319 --> 00:21:47,317 but not that many and it also came with some significant downsides. 243 00:21:47,317 --> 00:21:49,866 For one, cost. 244 00:21:49,866 --> 00:21:58,372 The QL line of lighting from Philips was very much a specialized commercial product and I’ve been having a heck of a time finding original pricing, 245 00:21:58,372 --> 00:22:01,157 but you can bet it was quite high. 246 00:22:01,157 --> 00:22:04,509 Not only had they created a new kind of fluorescent lamp, 247 00:22:04,509 --> 00:22:09,853 but they had to manufacture specialized electronics and the power couplers. 248 00:22:09,853 --> 00:22:15,428 The lighting system really only made sense in applications where relamping was an operational headache 249 00:22:15,428 --> 00:22:18,904 or its operating method offered improved safety - 250 00:22:18,904 --> 00:22:26,237 apparently they saw success in the oil and gas industry due to regulations concerning explosion-proof lighting. 251 00:22:26,237 --> 00:22:31,077 GE’s take on the technology was sort-of consumer focused, 252 00:22:31,077 --> 00:22:38,697 and the Genura bulb retailed for about $30 in 1994, equivalent to $65 today. 253 00:22:38,697 --> 00:22:44,902 But that’s a pricey light bulb especially considering its expected life isn’t all that great. 254 00:22:44,902 --> 00:22:50,829 It’s certainly much better than the 1 or 2,000 hours you could expect out of an incandescent flood bulb, 255 00:22:50,829 --> 00:22:55,619 but it was barely an improvement over existing fluorescent technology. 256 00:22:55,619 --> 00:23:01,764 You needed to really, really want fluorescent lighting in this specific form-factor, 257 00:23:01,764 --> 00:23:09,820 and I find it interesting that GE really didn’t bother to explain what’s so cool about this technology on the box. 258 00:23:09,820 --> 00:23:13,934 They're just calling this an electronic compact fluorescent lamp. 259 00:23:13,934 --> 00:23:18,399 Which is true but certainly underselling it. 260 00:23:18,399 --> 00:23:25,039 But the biggest issue, and what I think is likely  the main reason this technology never took the world by storm, 261 00:23:25,039 --> 00:23:29,345 is that it’s still fundamentally fluorescent lighting. 262 00:23:29,345 --> 00:23:34,997 Yes it was longer-lived, but it still had kinda meh light quality. 263 00:23:34,997 --> 00:23:39,715 And, because fluorescent lights are very much not point-sources of light, 264 00:23:39,715 --> 00:23:42,925 it was hard to direct the light these emitted. 265 00:23:42,925 --> 00:23:46,876 This 200W lamp was originally housed in this flood fixture, 266 00:23:46,876 --> 00:23:53,882 and while you could point this in a direction, it still casts a very wide beam of light. 267 00:23:53,882 --> 00:23:57,512 I don’t even think you could describe it as a beam. 268 00:23:57,512 --> 00:24:04,945 The QL lamps were more compact, but they still emitted diffused light which is difficult to control. 269 00:24:05,040 --> 00:24:07,527 Take street lighting as an example. 270 00:24:07,527 --> 00:24:10,961 I've encountered a few induction street lamps in the wild, 271 00:24:10,961 --> 00:24:17,827 but they all have about as much beam control as a circline fluorescent light stuck in the middle of the kitchen ceiling. 272 00:24:17,827 --> 00:24:20,134 Because that’s pretty much what they are. 273 00:24:20,134 --> 00:24:28,632 And the inverse square law means that you can’t place the lamps too high above the street or they just won’t offer effective light output. 274 00:24:28,632 --> 00:24:33,528 This ultimately means you need many more of them placed closer together. 275 00:24:33,528 --> 00:24:40,980 High-intensity discharge lamps like high pressure  sodium and metal halide produce all their light in a small arc tube 276 00:24:40,980 --> 00:24:46,792 which allows fixtures with optical systems to focus the light they produce into a narrow beam, 277 00:24:46,792 --> 00:24:51,715 permitting the use of fewer fixtures by placing them higher in the air. 278 00:24:51,715 --> 00:24:56,457 And actually, the Genura lamp demonstrates this downside quite well. 279 00:24:56,457 --> 00:25:02,360 While it mimics the basic appearance of an incandescent BR flood very faithfully... 280 00:25:02,360 --> 00:25:03,978 at least from the face of it, 281 00:25:03,978 --> 00:25:08,241 there’s no directionality to the light it produces. 282 00:25:08,241 --> 00:25:16,654 Even a frosted lamp like this produces a somewhat narrow beam of light thanks to fact that the filament is placed far down the reflector 283 00:25:16,654 --> 00:25:22,642 and that is very important to both the character and effectiveness of the light it produces, 284 00:25:22,642 --> 00:25:25,920 especially when recessed in ceiling can fixtures. 285 00:25:26,560 --> 00:25:30,103 This lamp simply cannot recreate that directional light, 286 00:25:30,103 --> 00:25:36,817 and I would imagine that presented problems from both an  aesthetic perspective and a functional one, too. 287 00:25:36,817 --> 00:25:43,455 It may be the same number of lumens,  but when fired in all directions and not mostly downward, 288 00:25:43,455 --> 00:25:46,897 the room might be underlit compared to before. 289 00:25:46,897 --> 00:25:52,781 And let’s not forget that conventional fluorescent technology saw lots of innovation, too. 290 00:25:52,781 --> 00:26:01,329 If any of the lighting nerds out there have been wondering why I never touted the flicker-free light output created by the high-frequency drivers in these things, 291 00:26:01,329 --> 00:26:06,913 that’s because electronic ballasts for traditional tubes did the same thing. 292 00:26:06,913 --> 00:26:09,991 They didn’t operate anywhere near these frequencies, 293 00:26:09,991 --> 00:26:16,494 but they were fast enough for the persistence  of the phosphors to produce truly continuous light output. 294 00:26:16,494 --> 00:26:20,730 That also increased the energy-efficiency of fluorescent lighting. 295 00:26:20,730 --> 00:26:28,119 As a matter of fact, a bog-standard T8 tube is  more energy-efficient than either of these induction lamps. 296 00:26:28,119 --> 00:26:30,370 And then of course there’s the CFL. 297 00:26:30,370 --> 00:26:34,088 Those, too, got electronic ballasts and all the benefits thereof 298 00:26:34,088 --> 00:26:39,605 and they were available in much more modest  power outputs than induction lamps. 299 00:26:39,605 --> 00:26:44,994 Sure, the Genura lamp is a more elegant solution  than sticking a coil in a fake bulb, 300 00:26:44,994 --> 00:26:49,983 but… is its elegance worth the extra cost? 301 00:26:49,983 --> 00:26:53,616 The market clearly decided no it wasn’t. 302 00:26:53,616 --> 00:26:59,795 I mean, this lamp was sold long before the old curly-q CFL went mainstream. 303 00:26:59,795 --> 00:27:07,189 Once we figured out how to make those cheaply, small induction lamps like this just hardly made any sense at all. 304 00:27:07,189 --> 00:27:11,925 And when ordinary fluorescent lights already had a 10,000 hour lifespan, 305 00:27:11,925 --> 00:27:18,880 well frankly you just had to be extremely committed to the idea of a lamp which could last 20 years without being touched. 306 00:27:19,534 --> 00:27:22,826 That is, if it makes it that long. 307 00:27:22,826 --> 00:27:29,993 The weak point in the induction lamp isn't the discharge tube, it's the electronics inside this box. 308 00:27:29,993 --> 00:27:35,812 And while it certainly is possible to produce electronic circuitry which lasts 100,000 hours, 309 00:27:35,812 --> 00:27:39,354 well let’s just say there are never any guarantees. 310 00:27:39,354 --> 00:27:44,366 Honestly props to GE for being so realistic with these lamps. 311 00:27:44,366 --> 00:27:49,831 The QL line from Philips probably had the best  quality drivers of any commercial system 312 00:27:49,831 --> 00:27:53,791 and since they were separated from the lamp they didn’t have  to deal with heat. 313 00:27:53,791 --> 00:28:02,070 But had this tech gone mainstream, we’d no doubt have the same race to the bottom that plagues so many things. 314 00:28:02,070 --> 00:28:04,970 But of course now this is all moot. 315 00:28:04,970 --> 00:28:13,360 The LED has trounced every lighting technology that we’ve ever made on energy efficiency, quality of light, and flexibility. 316 00:28:14,240 --> 00:28:18,173 We still have the same race-to-the-bottom nonsense going on, unfortunately, 317 00:28:18,173 --> 00:28:25,108 and it’s not like there haven’t been some high-profile issues with LEDs (such as purple streetlights) 318 00:28:25,108 --> 00:28:29,450 but in general lighting is now just solved. 319 00:28:29,450 --> 00:28:30,889 We’re there. 320 00:28:30,889 --> 00:28:34,763 Aside from some cheap builder-grade light bulbs I still have kicking around, 321 00:28:34,763 --> 00:28:39,745 I personally haven’t needed to replace a light bulb in several years. 322 00:28:39,745 --> 00:28:44,122 That’s no doubt helped by the fact that I generally only buy high-quality bulbs 323 00:28:44,122 --> 00:28:49,840 and I use dimmers nearly everywhere so rarely are any of my lights at full-brightness, 324 00:28:49,840 --> 00:28:50,654 but yeah. 325 00:28:50,654 --> 00:28:53,935 I’m certainly not pining for the days of old. 326 00:28:53,935 --> 00:28:59,246 But luckily our path to get here was  filled with all sorts of wacky nonsense like this. 327 00:29:00,260 --> 00:29:02,855 ♫ electromagnetically smooth jazz ♫ 328 00:29:03,728 --> 00:29:05,859 And because it’s formed in a loop, 329 00:29:05,859 --> 00:29:12,036 that induced voltage results in current flow which causes the lamp to light. 330 00:29:12,036 --> 00:29:13,416 Except it didn’t. 331 00:29:14,571 --> 00:29:19,596 Probably because… you need to be secured in place. 332 00:29:19,596 --> 00:29:22,982 Hopefully I didn’t just kill ya, that would be very problematic. 333 00:29:22,982 --> 00:29:25,683 For that reason, this is known as an induction lamp. 334 00:29:25,683 --> 00:29:28,867 And I cannot be sitting here with this in front of my eyes. 335 00:29:28,867 --> 00:29:30,887 …chilling in this little glass appendage. 336 00:29:30,887 --> 00:29:33,247 Is that the right one? Nope. I pointed at the wrong one. 337 00:29:33,247 --> 00:29:36,926 I mean, there’s not a not… not a… dada da! 338 00:29:37,520 --> 00:29:43,040 And in this lamp, [glass scraping sounds] the underside… that I’m sure sounded horrible.  339 00:29:43,040 --> 00:29:46,394 …have been demonstrated many many times over the past. 340 00:29:46,394 --> 00:29:48,285 In the… in… ugh. 341 00:29:50,000 --> 00:29:52,499 One would have to call this technology... 342 00:29:52,499 --> 00:29:55,307 totally tubular, amirite? 343 00:29:55,730 --> 00:29:57,309 That one hurt to the core. 344 00:29:58,126 --> 00:29:59,175 Both of them, actually. 345 00:29:59,175 --> 00:30:03,046 Hey did you know that Michael used to be a taxi driver? 346 00:30:03,046 --> 00:30:05,403 He switched to a career in science since he only got one fare a day.