I agree whole heartedly. First class content & production..

I'm currently working on 8 more videos, 1 of which is almost done, unfortunately they take a lot of time to make, especially seeing as I only work on them on the occasional weekend or after my day job.

I'm starting to think we ought to run 12VDC to our light sockets and have one big converter for the whole house. They already make 12V lighting for houseboats and caravans/motorhomes.

@@charleslambert3368 Exactly what I have been thinking for a while now. I believe we will start seeing these in near future.

​@@charleslambert3368, people do that already. Sometimes 12V, sometimes 24V (or maybe even 48V).

it is not a resistor though

It's not an inductor, it's a resistor

It's not an inductor, it's a resistor.

You'll be driving the remaining LED's harder due to the missing one I think. Better to replace if you can. Although with the extra ventilation it probably won't matter. I'd be a little cautious running it without the diffuser.

That's a bad idea, the bulb is gonna fry in very few uses

Interesting, I've heard the silicone encapsulation is meant to improve thermal conductivity to the outer shell and eliminate joint vibration failures, not sure about high thermal cycling. I'm tempted to buy a new one from 2022 to see if they've changed anything since the 2019 design.

Thanks for the info

HAHAHA were same brother . i worked on engineering department in vishay, at wirebonding do like this and coss-sectioned on it after that do SEM (scanning electorn microscope) and an x-ray.

I've tried to chip off the coating on other components before, it's very difficult to do so without damaging what's under it so I wouldn't be confident if I found a broken wire to say if it was the failure point or if I had just broken it. If I were to do this again I would use an acid to dissolve the coating.

Some things that give it away it's an inductor: - PCB overlay has it marked as "L1" and an inductor symbol between the pins - Axial through hole inductors are often that light blue colour and the colour bands decode to a sensible inductance value - The cross section shows it has a ferrite core and low resistance copper wire wound around it, a wire wound resistor would use a nichrome alloy wire wound around a ceramic core. The colour bands are very similar to resistors, the multiplier is the only difference on inductors, there's plenty of online colour band decoders that make it very easy.

Some things that give it away it's an inductor: - PCB silkscreen has it marked as "L1" ("L" in honor of the physicist Heinrich Lenz) and an inductor symbol between the pins (easiest way to know it's an inductor) - Axial through hole inductors are often that light blue colour and are much wider than resistors with a slightly lumpy midsection - The colour bands decode to 3 mH which is a relatively large inductance value, but makes sense in the circuit (if it were a resistor it would be 3k Ohms 10% which would limit the current too much and dissipate about 1.5 W of the 5.5 W of this LED bulb) - It measured almost 0 ohms but about 3 mH in an LCR meter - The cross section shows it has a ferrite core and low resistance copper wire wound around it, a wire wound resistor would use a nichrome alloy wire wound around a ceramic core.

The DURIS E 2835 series LED chip that's in this bulb is rated to have a forward voltage of between 8.4 and 9.8 V, typically 9.5 V. To test them I used a Keithley DMM6500 bench multimeter in diode mode, unlike a typical handheld multimeter it has a relatively high diode test voltage of 7 to 12 V and can do higher test currents. But you can do the same test with a lab PSU at a similar voltage (>6V for those 3 die LEDs) in constant current mode set to just a couple of milliamperes.

The LEDs in this light bulb are special, they have three LED dies in one package so have a forward voltage of between 8.4 and 9.8 V, typically 9.5 V. To test them I used a Keithley DMM6500 bench multimeter in diode mode, unlike a typical handheld multimeter it has a relatively high diode test voltage of 7 to 12 V and can do higher test currents. But you can do the same test with a lab PSU at a similar voltage (>6V for those 3 die LEDs) in constant current mode set to just a couple of milliamperes. You could also do this with a 12 V battery, just make sure you use a resistor to limit the current otherwise you'll break the LED.

@@WizardTim Thank u very much for replying. 👍👍

I used a Keithley DMM6500 bench multimeter in diode mode, unlike a typical handheld multimeter it has a relatively high diode test voltage of 7 to 12 V and can do higher test currents. But you can do the same test with a lab PSU at a similar voltage (>6V for those 3 die LEDs) in constant current mode set to just a couple of milliamperes.

The DURIS E 2835 series LED chip that's in this bulb is rated to have a forward voltage of between 8.4 and 9.8 V, typically 9.5 V.

Thak you!

Thanks! I had 335 subscribers yesterday before posting my last video!

WizardTim I am telling you it's going to be big. Great job brother

Hay I jist became # 737 !

Hi, the multimeter is in diode mode when lighting up the LEDs, continuity mode usually won't supply enough current or voltage to make white LEDs light up. However additionally those LEDs aren't the typical single die white LEDs, they're OSRAM DURIS E 2835 series LEDs so they have a rated forward voltage of between 8.4 and 9.8 V, typically 9.5 V. So your multimeter has to have a rather high diode test voltage. In this video I used a Keithley DMM6500 bench multimeter in diode mode, unlike a typical handheld multimeter it has a relatively high diode test voltage of 7 to 12 V and can do higher test currents. But you can do the same test with a lab PSU at a similar voltage (>6V for those 3 die LEDs) in constant current mode set to just a couple of milliamperes, just be careful of the PSU's output capacitance damaging the LEDs if you set the voltage too high.

Agreed, I even have a special bench-top multimeter than I can screen capture from, but completely forgot when recording this video to do that! In the new videos on this channel I have thankfully remembered (so far) to record the multimeter and put it in the video. The inductor smooths out the noise and voltage spikes on the AC mains to protect the LED circuit in the bulb but also prevent noise from the LED circuit going back out into the AC mains and interfering with other stuff in your house, it does this in combination with the capacitor, this is called an 'LC filter'. It does this by absorbing the voltage spikes in it's magnetic field. A resistor often used for a similar job in combination with a capacitor this is called a 'RC filter', but they have no magnetic field so instead convert energy into heat, thus it would get extremely hot and make the bulb very inefficient. It's often difficult to tell the difference between those axial inductors and resistors but typically you can tell based on the shape, inductors are usually shorter and wider than most resistors. Also ones like the brown one the coating is thin enough you can just make out the windings. In this example it's easier because there's a little inductor symbol on the PCB between the pins and it's labeled 'L1'.

​@@WizardTim Thanks a lot, that was a very good detailed explanation. I'm surprised how no video I have watched for the past week trying to learn electronics explained or even mentioned inductors. I even googled inductors vs resistance and I didn't get a clear answer or picture comparison. I just bought a new multimeter so I'm excited to try and test these components myself.

@@mhnoni Inductors aren't used anywhere near as much as resistors or capacitors so they're usually not taught until later in electronics. You'll probably understand it better if you think of inductors as the compliment to a capacitor rather than a resistor. - Capacitors try to smooth *voltage* by storing energy in their *electric field* - Inductors try to smooth *current* by storing energy in their *magnetic field* - Resistors *limit current* by dissipating energy as *heat* Also you'll find almost all multimeters can't measure inductance, usually you're measuring resistors, capacitors or diodes, you rarely need to measure the inductance of an inductor so they don't include that feature most of the time, in this video I was just measuring the resistance of the inductor to check it wasn't broken internally which of course it was broken. I have an LCR meter to precisely measure inductors, capacitors, resistors and all their characteristics, but you only really need that when designing more advanced circuits.

Some things that give it away it's an inductor: - PCB overlay has it marked as "L1" and an inductor symbol between the pins - Axial through hole inductors are often that light blue colour and the colour bands decode to a sensible inductance value - It doesn't make sense for their to be a resistor in that place in the circuit but an inductor makes sense - The cross section shows it has a ferrite core and low resistance copper wire wound around it, a wire wound resistor would use a nichrome alloy wire wound around a ceramic core.

@WizardTim thank you God bless you

It appeared to be a 3-pin ferrite E core non-isolated transformer for 240 V AC to about 24 V DC.

Some things that give it away it's an inductor: - PCB overlay has it marked as "L1" and an inductor symbol between the pins - Axial through hole inductors are often that light blue colour and the colour bands decode to a sensible inductance value - It doesn't make sense for their to be a resistor in that place in the circuit but an inductor makes sense - The cross section shows it has a ferrite core and low resistance copper wire wound around it, a wire wound resistor would use a nichrome alloy wire wound around a ceramic core.

Likely a combination of EMI/noise suppression, power factor correction, inrush limiting and ripple smoothing on the main DC capacitor.

@@WizardTim Thank you very much.

The inductor resists sudden changes in current by storing energy in it's magnetic field, this is useful for EMI/noise suppression in this LED bulb as it dampens the current spikes from the switching power supply from being conducted back into the house mains cables and possibly interfering with other devices or radiating as a radio signal. It can also help smooth the AC ripple on the DC bulk capacitor as well as adjust the power factor but it's main use is probably for basic EMI suppression (higher power devices will have proper "common and differential mode" EMI suppression filters).

I assume you've tested the 24 LEDs individually like I showed in the video to make sure they all still work, if one doesn't work and they're all wired in series the bulb won't light at all, I would imagine this is the most likely cause of it not working. The 'square redish parcel' in your bulb is most likely a polyester X class capacitor being used in a 'capacitive dropper' power supply which is a very different design to the LED bulb in this video, if this is the case it should be a bit bigger than the one in my LED bulb (guessing it will be around 470 nF for a 3.6W bulb). If you have a multi-meter that measures capacitance you can test to see if the capacitor is still good based on the capacitance marking on the side of it (you may have to remove it from the PCB to test it 'out of circuit' to get an accurate reading), those types of film capacitors often degrade over time losing their capacitance which causes the bulb to be dimmer until it stops working completely. The 7 small black squares are likely a combination of diodes and resistors, those are unlikely to be the fault but you can test those with a multi-meter.

@WizardTim Hi. All led,s tested including on the back of the disk, the 2 solderd points. The x capacitor says cbb22 684J 400v. On 2000k test it says 550. I can't get any reading on the ų value. The other capacitor is a 4.7 ųf 400v and reads on 2000k 460 and again no reading on the ų value, trying from 20ų to 200m. The wires from the pcb to the bayonet prongs are good. Am i right in thinking if i connected a 3.6w power source to the back of the led disk they should light up if they are good? Thanks, John

@@knaptonmawson The 684J marking means the capacitor is "68 with 4 zeros" 680000 pf (680 nF). Your multi-meter may not be able to measure the capacitor as it's too small for it, it would appear as "0000.68" in the 20u range, assuming you have 2 decimal places on the LCD. I think your options are to de-solder the X class capacitor to measure it out of circuit on a better multi-meter or just assume it's bad and see if replacing it with an exactly equivalent capacitor will make it work again. I would recommend visiting an electronics hobby shop or even a makerspace if you have one nearby, you might be able to buy the right capacitor there or someone there might be able to test the capacitor for you but also help you test it safely. Here's a video that explains this type of capacitive dropper power supply: kzfaq.info/get/bejne/Y9RiZcaiv9HcfoU.html To light up the LED disk you'll need the correct voltage and enough current rather than just any power source with enough watts, for 24 LEDs in series you'd need something between 40 and 100 V DC but you will also need to limit the current otherwise it will draw too much current and blow up instantly.

@WizardTim Thanks a bunch, i will consider the possibility of replacing the x capacitor. I hate throwing things away that looks simple enough to repair .(if you know what you are doing) I do understand that you need resistors when using leds, so you dont just instantly blow them. John.