The cheap Chinese bulb that won't turn off

Share
HTML-code
  • Published: 05 July 2019
  • The first 200 people to sign up at brilliant.org/stevemould/ will get 20% off an annual subscription that gives you access to the full archive of Daily Challenges and every single course.

    Check out Mehdi's video over on ElectroBOOM here:
    pedofolie.info/video/_bgUy6zA0ts/video.html

    These LED bulbs will continue to draw power from the mains indefinitely even once they're switched off and the circuit is broken. But how?!

    You can buy my books here:
    stevemould.com/books

    You can support me on Patreon here:
    patreon.com/stevemould

    just like these amazing people:

    Glenn Watson
    Peter Turner
    Joël van der Loo
    Matthew Cocke
    Mark Brouwer
    Deneb

    Twitter: twitter.com/moulds
    Instagram: instagram.com/stevemouldscience/
    Facebook: facebook.com/stevemouldscience/
    Buy nerdy maths things: mathsgear.co.uk
  • Science and Technology Science and Technology

Comments • 2 202

  • J-man72 b
    J-man72 b  1 days back

    The voltage that is induced into the second wire is only capable of very low current, almost nothing, so the other bulb that draws more current is not likely to glow because there is almost no current flow.
    The voltage is induce from one wire to an adjacent wire through capacitive(and inductive) coupling, this is why you don't run audio and video wires/cables next to power wires/cables.
    Capacitive: the voltage in one wire effects the electrons in the other wire.
    Inductive: The current flow in the wire creates a moving magnetic field which will induce a current/voltage(closed loop/open loop) into an adjacent wire.

    • Mübin Icyer
      Mübin Icyer  2 days back

      Please make a video about Arago spot.

      • alan connelly
        alan connelly  3 days back

        You wired the on/off switch wrong, your dangerouse with electrical power and wiring.

        • J-man72 b
          J-man72 b  11 hours back

          @alan connelly Millions of homes in N.A. are wired the way I explained.
          And for safety, if you don't know what you're doing, don't touch electrical, period.

        • alan connelly
          alan connelly  17 hours back

          @J-man72 b no power feeds to switch, switch then feeds power to load (light), that's how a safe switch leg (or any switch) works safely. That way when you turn the switch off there is no power at the bulb (load), far safer and more human error proof.

        • J-man72 b
          J-man72 b  1 days back

          No, that's how a switch-leg works, power and neutral are at the light, one wire brings the hot/line down to the switch, the other wire in the cable returns it to the light(the switched leg), in North America it's black/red as the line/hot wire, and white as the Neutral/Identified wire, the white is connected to the hot/line and sent to the switch, it is then returned to the light on the black so that you don't have 2 whites attached to the light, THIS IS ELECTRICAL CODE.

      • Shanon Bertin
        Shanon Bertin  3 days back

        I now understand why when I plug my laptop cable in the outlet first, it produces a little crack !







        Also thanks for giving the idea to create an electro gun (I was just being nerd)






        🤫

        • Robb Cochran
          Robb Cochran  3 days back

          ... It looks like a cap to some..., And it could act AS a cap sure... But ... It doesnt. When the HOT and Ground Leads are discomected entirely while the rest if the circuit is in tact... I wish i could respond with the schematic i just drew... :(.

          • Robb Cochran
            Robb Cochran  3 days back

            ... not at the SW... Which Should be AT the V-IN or Current-Source-IN or the HOT line at the very beginning of hte circuit... Which is not the case here... And... Is why a certificate as an Electrician means NOTHING if you dont know how it all Really,... I mean Really ... really works... And its also why a lot of peoples houses catch fire lol.... Bad Wiring.

          • Robb Cochran
            Robb Cochran  3 days back

            ... basically the feild dies and so does the light if you diclsconnect the HOT

        • Robb Cochran
          Robb Cochran  3 days back

          Its a Jewel Theif and a really bad Tesla Coil? One Wire with an AC Current Potential (which is connected to the lights Circuitry) ... Directly Next to a Copper/Aluminum Dead Line (also connected to the light directly) reacting to the Build and Collapse of the Electromagnetic feild.. its actually NOT a capacitor reaction... Its an Inductive Reaction... As the LOAD current is Directly connected to One lead of the light... And then the Large Coil (to Neutral or Ground) is Also connected to the light directly... Met half way to GROUND with a SWitch or Air Gap... And AIR is semiconductive which really just determines the extra brightness of the bulb... It would be dimly lit either way... (Air or Vaccum Tube) due to Reluctance and Induction throught the parallel Feilds of the coil of wire... Which is Current Loaded... Tryin to find Ground - even a wire that isn't connected to ground still has an electromagnetic feild... that's what makes those tests lights light up there still an electric field inside of the wire... I could go on and on but its not a CAP ... Sorry

          • Robb Cochran
            Robb Cochran  3 days back

            Capacitive Inductive reluctance??? Im dumb so...

            • Em P
              Em P  3 days back

              do not do this while its life, you can do everything when its not plugged in

              • Imax Ion
                Imax Ion  3 days back

                sorry dumb question, can we measure the mass of electrons ??

                • Dead Elf
                  Dead Elf  3 days back

                  Where can we buy the bulbs?

                  • Staycalm2010
                    Staycalm2010  3 days back

                    I tried brilliant a little while a go in the hope to improve my math skills, but I found it to difficult so i didn't stick with it.

                    • wolfedog99
                      wolfedog99  3 days back

                      When I was an electrician I would often find completely disconnected circuits(bare at both ends) with 70v when using a high impedance meter to ground, simply from the capacitive coupling with other circuits that share a conduit. Older analog volt meters don't pick it up because they tend to use a much lower impedance which drains the charge faster than it can build.(low and high here are 100Kohms and 10Mohms) Though I never bothered to calculate or test the actual power consumed, or if a resistor shunt like a bulb would change the power consumed, I'm guessing low milli-amps or micro-amps range testing is needed.

                      • J-man72 b
                        J-man72 b  1 days back

                        I've come across it lots of times with tic testers, only when I pull out a meter to confirm will it show as ~3volts, open circuit I could easily see it being ~70 volts.

                    • Stamen Stoychev
                      Stamen Stoychev  4 days back

                      Came here for therapeutic purposes...

                      • Anuj Kankaria
                        Anuj Kankaria  4 days back

                        How will the brightness of the LED be affected with cable length? When the switch is turned off

                        • Anuj Kankaria
                          Anuj Kankaria  1 days back

                          @J-man72 b okay. Thanks mate

                        • J-man72 b
                          J-man72 b  1 days back

                          Longer wire increases the capacitive effect, it may only get a bit brighter before other losses cancel out any more gains.

                      • Tech Things
                        Tech Things  4 days back

                        So, long will it last without getting any extra power?

                        • J-man72 b
                          J-man72 b  1 days back

                          It's leaching power off the live wire, so as long as it's live, it will continue to glow, even though the switch is open and there is no physically connection (closed loop).

                      • Isaac Bernath
                        Isaac Bernath  4 days back

                        People with British accents just sounds smarter.. Oh nvm, some are actually freakin brilliant...

                        • Jekabs Karklins
                          Jekabs Karklins  4 days back

                          I researched this long time ago and the explanation was different. The reason why lightbulb glows is because switch is mounted only to one wire (b.t.w. in households to neutral by Europe standard) . And because LED requires so little power, the neutral wire, although unplugged, still works as a ground. It is because of the long cable length, which is able to dissipate electric charge carriers in surroundings.

                          • Tristan Ryan
                            Tristan Ryan  4 days back

                            Hell yea dude

                            • a1919akelbo
                              a1919akelbo  4 days back

                              Its not really acting like a capacitor, it's acting more like a 1:1 transformer, the cabling is so long it produces a small current that usually doesn't light bulbs, but i assume that is a low current light?

                              • J-man72 b
                                J-man72 b  1 days back

                                It is acting like a capacitor.
                                https://circuitglobe.com/capacitance-of-transmission-line.html

                            • finity69x2
                              finity69x2  5 days back

                              And if your friend can't turn off the bulb it's because they switched the neutral instead of the hot wire. I'm an electrician and I get VERY PISSED when I find out that people switch the neutrals. It works (in most cases aside from this) but it's unsafe because no one expects the neutral to be switched. In this case because the hot wire is always connected to the bulb then you get that "capacitive" effect and the light stays on. If you switch the hot like you're supposed to then the hot is disconnected from the bulb and the neutral bleeds off any capacitance in the wire to ground so the light goes off.

                              • dsb electrical david betteridge

                                like the vids maybe a double pole switch sort it

                                • Top Tunes
                                  Top Tunes  6 days back

                                  Electrons flow from negative to positive not positive to negative

                                  • Top Tunes
                                    Top Tunes  3 days back

                                    @wolfedog99 In a wire charge carriers are electrons. A positive carrier is a fudge used because we still use the convention that electricity flows from positive to negative when in reality is is the other way round.

                                  • wolfedog99
                                    wolfedog99  3 days back

                                    Yes electrons are negative, but not all charge carriers are electrons and it works equally well to speak of charge flow as either positive carrier or negative carrier flows, just as long as the discussion is consistent.

                                  • circuit shock Raprap
                                    circuit shock Raprap  4 days back

                                    True, electron move negative going to positive.

                                • Ronald Moreira
                                  Ronald Moreira  6 days back

                                  "His voice is so soothing, I listen to him for terapeutic reasons"


                                  -Mehdi

                                  • Donald Sleightholme
                                    Donald Sleightholme  6 days back

                                    i think that it’s more like a inductor than a capacitor? 🤔🤷‍♂️

                                    • Top Tunes
                                      Top Tunes  3 days back

                                      Please ignore this post. I thought I was responding to a different post. I should have left the beer alone last night !

                                    • Top Tunes
                                      Top Tunes  3 days back

                                      @dingo The voltage across the inductor is - L * Di/Dt. The principle is how points in car ignition systems used to work and cattle fences. The inductor also stores energy

                                    • dingo
                                      dingo  3 days back

                                      Top Tunes You wouldn't get a shock as the capacitance is so low that it can only pass a tiny current - too small to even feel. The voltage wouldn't stay at 240V as the "capacitor" and your bpdy would form a potential divider, and as the impedance of your body is much lower than that of the capacitor, almost all of the voltage would be across the capacitor, not you.

                                    • Top Tunes
                                      Top Tunes  6 days back

                                      If is is capacitance then the only voltage on the cable must be 240 v which clearly it isn't otherwise you would still get a shock after the switch is open. The simple test it to remove the LED from the circuit after the switch is opened. If the LED is still glowing then it is probably down to the LED material itself otherwise ,faulty switches or dodgy electronic design allowing some stored charge to remain after the switch is opened. You also have to remember the switch circuit does not introduce much wiring into the circuit and the capacitance would be minimal. Likewise inductance of such a cable would also be minimal - if not the energy would be dissipated as a spark acros the switch as it opened . Questionable LED's is the best bet on this one.

                                  • towards infinity
                                    towards infinity  7 days back

                                    Wanda wanda wanda wanda 😂😂😂😂

                                    • MrMegaPussyPlayer
                                      MrMegaPussyPlayer  1 weeks back

                                      Have thought long and hard, and not sure if those bulbs that don't glow actually consume less energy (even if it were above the detection level of the equipment of you electricity company) as said in this video, as all that the bulbs that don't glow do is shunting it with a resistor.

                                      • 00Skyfox
                                        00Skyfox  1 weeks back

                                        I love listening to Steve talk. His voice sounds so similar to the late David Bowie.

                                        • Bruce Kives
                                          Bruce Kives  1 weeks back

                                          The problem is that your electrician messed up when wiring up your switch. According to electrical code, you are supposed to switch off the Hot or Live wire. For a LED bulb to do this, you are switching off the Neutral.

                                          • Gerry Campion
                                            Gerry Campion  1 weeks back

                                            blah blah blah free energy blah blah blah
                                            I actually have one of these in my car, so that's not good.

                                            • Seb Gibbs
                                              Seb Gibbs  1 weeks back

                                              Bulb is being powered by electrical cable power loss.

                                              • RONI TJEN
                                                RONI TJEN  1 weeks back

                                                what brand of that bulb?, i want to test in my home.

                                                • Adrian Castravete
                                                  Adrian Castravete  1 weeks back

                                                  OK, playing with water over all that electric wiring... :|

                                                  • Aimless Drifter
                                                    Aimless Drifter  1 weeks back

                                                    I think it's acting as an inductor not a capacitor, and you probably have AC current tuning in those wires.
                                                    I would guess that AC current in one wire generates EMF and induces very weak current in the neutral wire causing light to shimmer. The difference with incandescent bulb is that minuscule induced current is not enough to generate light or heat as oppose to LED lights where even smallest current is enough.
                                                    - 2nd Year Mechanical Engineering Student (not Electrical Engineer so electricity is not my specialty and I could be wrong)

                                                    • Sathish Neelakandan
                                                      Sathish Neelakandan  1 weeks back

                                                      His voice is indeed therapeutic.

                                                      • Bloody JMF
                                                        Bloody JMF  1 weeks back

                                                        I have a 6m long hallway and 2 stripes of 220V Leds with a rectifier. Once all light are out they still have a slight glow to them. Always wondered why.

                                                        • panicland
                                                          panicland  1 weeks back

                                                          That Electroboom-colab worked, you now have a new subscriber :)

                                                          • Jacob Child
                                                            Jacob Child  1 weeks back

                                                            1.3k Apple users watched this video.

                                                            • Chris Lewis
                                                              Chris Lewis  1 weeks back

                                                              Tesla didn't win, it was Westinghouse that promoted AC over Edison's DC

                                                              • eth3rl0rds
                                                                eth3rl0rds  1 weeks back

                                                                I almost fell asleep!

                                                                • Lewis Kelly
                                                                  Lewis Kelly  2 weeks back

                                                                  Electrobooms channel is a pile of shit and it is a shame you associate with him

                                                                  • Chris John
                                                                    Chris John  2 weeks back

                                                                    love the plane

                                                                    • Darth Cookie
                                                                      Darth Cookie  2 weeks back

                                                                      8:20 "but I know someone who is"
                                                                      I was like ohhhh shit, here comes BILL NYE!

                                                                      • The ÀppleSauce queen
                                                                        The ÀppleSauce queen  2 weeks back

                                                                        I came and described to you because of electro boom!

                                                                        • Johny Rivers
                                                                          Johny Rivers  2 weeks back

                                                                          So its because of induction?

                                                                          • BatBat
                                                                            BatBat  2 weeks back

                                                                            This is inductive reactance forming residual magnetism in that coil of wire which had just become a large electromagnet when you plugged it in. This is just like a makeshift transformer. I don't think your electrons compressing theory is correct -> When you break the electrical connection, the mains no longer has a flow of electrons, and thus can NOT "compress" the electrons in that live wire. Electricity doesn't just push electrons through a wire unless that same wire can simultaneously return those pushed electrons back to its source (via the neutral lead). There isn't even a slight initial "push" to create compression until that very moment the neutral lead provides the "pull".

                                                                            • Scriptminer
                                                                              Scriptminer  2 weeks back

                                                                              That is really interesting! Thanks for explaining!

                                                                              • Pax Humana
                                                                                Pax Humana  2 weeks back

                                                                                What if people that have done what is in this video could combine this with hydroelectric energy that also uses the water cycle to essentially create not only a virtually unlimited amount of energy, but also potentially perpetual energy and power as well, and with zero emissions to boot?

                                                                                • Marcel Zuidwijk
                                                                                  Marcel Zuidwijk  2 weeks back

                                                                                  @Steve Mould, what happens when you switch the live and neutral? So live goes to the lamp, and the neutral to the long wire.

                                                                                  • David Hill
                                                                                    David Hill  2 weeks back

                                                                                    Good question. I think the light still would glow, because one leg of the 50m cable still has mains voltage.

                                                                                    Having the switch on the neutral wire like that will result in a circuit that works fine, but means the light socket is always live even if the switch is off. That's unsafe.