LED Energie LED bulb teardown

LED Energie brand LED bulb with following data stopped to work properly:

230V 50Hz 7W E27

450lm 3000K 60mA 20D

3684 Mod.5161

So lets make a tear-down

Inside

There seems to be 20 small LEDs in series inside bulb and one of them burned black. As such this LED string is expected to need around 70V over it. LEDs were soldered to a aluminium circuit board thar was glued to aluminium tube inside plastic lamp base part.

Look at the circuit board

This looks like power supply is basically an RC current limiting (with small coil) followed by rectifier and small electrolytic filtering capacitor. In addition there are 470k bleder resistors to discharge capacitors.

The big resistor is a bit suspect here. According to color code it should be 100 ohms, but multimeter reading says 295 ohms. I suspect that either it has changed value or color code has changed colors due heating.

The RC circuit capacitor was 1.1uF 400V. The filter capacitor after rectifier was 2.2uF 400V electrolytic.

Here is the reverse-engineered circuit disgram:

124 Comments

  1. Tomi Engdahl says:

    Christmas special Turn Any LED bulb into colourful RGB light| Maryy Christmas
    https://m.youtube.com/watch?v=1I4pQi12GLw&feature=youtu.be

    Reply
  2. Tomi Engdahl says:

    Make your own Dooby lamps – DIY Dubai lamps (strobing alert)
    https://www.youtube.com/watch?v=ISTB0ThzhOY

    A test to see if ordinary LED lamps can be under-run like Dubai lamps to make them last longer with reduced intensity and heat.

    To limit the current I used different values of series capacitor, which has a soft limiting effect, making it compatible with traditional capacitive dropper and linear regulator based lamps.
    This technique does not work with some lamps with switchmode based power supplies. They will tend to strobe due to the way the circuitry works.

    This project involves mains voltage, and suitable precautions should be taken during your experimentation.

    Reply
  3. Tomi Engdahl says:

    Exploring a Chinese magnetic “machine light” (with schematic)
    https://www.youtube.com/watch?v=UDrQ5aiCdJg

    Specifically sewing machines, but it does have other uses where you need a splash of light.

    By Chinese standards it’s actually quite well made and functional. The circuitry is good and the LEDs are an interesting type being run at a sensible level that will ensure a long life.

    This seems to be designed for Chinese factories, so I think it’s only available in 220V. But it will still light on 120V.

    Reply
  4. Tomi Engdahl says:

    Bodging a repair on a faulty ground uplighter
    https://www.youtube.com/watch?v=4goqsDGro7w

    This is a faulty ground recessed uplighter that was sent for our exploration by Douglas.
    It’s a classic example of premeditated landfill, with no replaceable lamp and a sealed case to try and stop water getting in.

    They are often mounted into a buried enclosure to ensure that anyone who works on them has to kneel on wet ground and fumble in stinky water to try and make a waterproof connection onto a cable that gets shorter every time a fitting is replaced. They’re usually powered from panels where all the RCDs/GFCIs have been bypassed to “fix the tripping issues”. (Not a good thing.)

    You can see this type of light littering the pavements of cities and “architectural” areas. They either shoot light pointlessly into space while dazzling pedestrians, or put blotchy skidmarks of light up the side of buildings. They are notable for flickering gently as their corroded LEDs light the internal drops of water on their lens, and occasionally emitting steam from their submerged electrical connections.

    Reply
  5. Tomi Engdahl says:

    Opening the 1W Dubai lamp (with schematic)
    https://www.youtube.com/watch?v=AM2DMuryw_A

    The smaller lamp bases often make it hard to fit decent drive circuitry into an LED lamp. Many manufacturers skimp by just having a low voltage ceramic capacitor and rectifier. But Philips have put some very interesting circuitry into this lamp.

    The lamps you’re not allowed to have. Exploring the Dubai lamps
    https://www.youtube.com/watch?v=klaJqofCsu4

    Reply
  6. Tomi Engdahl says:

    Crushing and hacking LED lamps
    https://www.youtube.com/watch?v=H09SI5qLmtY

    A very pleasant evening spent crushing and hacking some very similar looking LED lamps from different brands.

    If you have a go at crushing the plastic, then make extra sure it’s not glass, plastic coated glass or hard brittle plastic, to avoid getting cut. Gloves might be a good idea.

    The hack involves the current sensing resistors. As the LED current flows through them the voltage across them rises up until it reaches a threshold where the circuitry effectively increases its resistance until a current balance is reached. Sometimes there’s one resistor, but often there are two in parallel to allow fine tuning of the current. By dismembering one you can make the lamp run at much lower current and temperature. This makes the lamp run more efficiently and it will also last much longer than in its original form.

    Reply
  7. Tomi Engdahl says:

    So Many MISERABLY FAILED LED Lights
    https://www.youtube.com/watch?v=lIK1jnYr0yw

    Making ANY cheap design will cause failure and is more wasteful. STOP IT!

    Reply
  8. Tomi Engdahl says:

    Make EPIC custom crystal lamps
    https://www.youtube.com/watch?v=HZKu9QMN5xw

    To make these customised lamps you can use the openscad scripts included at the bottom of this video description area.

    Reply
  9. Tomi Engdahl says:

    The cheap Chinese bulb that won’t turn off
    https://www.youtube.com/watch?v=1uEmX5XClPY

    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?!

    Reply
  10. Tomi Engdahl says:

    Doobying a cheap LED floodlight with lux/efficiency readings
    https://www.youtube.com/watch?v=biEZ1TbdhhU

    During the stream I hooked capacitors in series with a cheap sealed 10W LED floodlight that is almost certainly baking its LEDs. This reduces intensity, but multiplies its lifespan significantly.

    This time I used a light meter to get an indication of how the intensity changed with current, and got a rough approximation of “lux per watt” at a height of 300mm (12″) from the front of the light. This was not an ideal testing scenario and is just for comparison on intensity.

    One of the most notable things was how the efficiency dropped as the light heated up when running at full power. LEDs are less efficient at higher currents and when they are hot, so modern lights are not only designed to fail fast for profit reasons, but also perform badly as they do so.

    Here are the results.

    Full power cold 10.7W, 3010 lux, 281 lux per watt.
    Full power hot 10.7W, 2800 lux, 261 lux per watt.
    1uf, 3.8W, 1460 lux, 384 lux per watt. (Capacitor voltage drop 62V)
    470nf, 1.9W, 840 lux, 442 lux per watt.
    330nf, 1.5W, 640 lux, 426 lux per watt.
    220nf, 1W, 450 lux, 450 lux per watt.
    100nf, 0.5W (estimated), 210 lux, 420 lux per watt. (Capacitor voltage drop 90V)
    47nf, 0.2W (estimated), 90 lux, 450 lux per watt.
    22nf, 0.1W (estimated), 30 lux, 300 lux per watt.

    At the lower levels the light’s internal leakage shunt resistor would be affecting efficiency.

    Reply
  11. Tomi Engdahl says:

    I wrecked B&Q’s biggest LED lamp then bodged a repair
    https://www.youtube.com/watch?v=Hcztjhyl6GM

    A teardown of B&Q’s (like Home Depot) biggest lamp. It didn’t go to plan.

    Things worthy of note. If opening one of these, you have to remove the two screws from the LED panel – as they aren’t just tapped into the aluminium heatsink plate, but into plastic pillars that hold everything in.
    Given the poor thermal coupling and 15.5W rating for such a small LED PCB I wonder if they melt those pillars. The base has reasonable heatsinking capability, but the poor contact hints at a short lamp life.

    I’m surprised that this lamp isn’t in the same style of the common single PCB lamps with a linear current regulator on the same panel as the LEDs. Especially given its high power rating. I guess they may evolve in that direction in the future, as it is a much simpler way of creating the high power lamps.

    Reply
  12. Tomi Engdahl says:

    Hacking an extra trashy Poundland LED lamp (with schematic)
    https://www.youtube.com/watch?v=5HTa2jVi_rc

    Reply
  13. Tomi Engdahl says:

    New LED lamp twist reverse engineered from a picture
    https://www.youtube.com/watch?v=toXaBxp1It8

    Just when you thought they couldn’t make an LED lamp simpler than the common linear regulator type, they come out with this.

    It’s basically a single package combining the rectifier and current regulator into a single package.

    These lamps work by using enough multi-chip LEDs in series to approach the normal mains voltage, but then use a linear current regulator to keep the current constant by acting as an active resistor, with a small voltage dropped across it.

    Reply
  14. Tomi Engdahl says:

    Dimming LED lamps with ordinary dimmers.
    https://www.youtube.com/watch?v=fWh2obSY0dQ

    Using a traditional phase angle control wall-plate dimmer (the usual type) is just a terrible way to dim LED lamps. The rough chopping of a 50/60Hz sinewave with sharp voltage transitions is very hard to convert to a proper smooth and flicker free dimming of an LED lamp over a decent range. LED lamps also provide a very low load with sudden drop-off of current which can make ordinary dimmers very unstable.

    Reply
  15. Tomi Engdahl says:

    Philips streetlight “ledgine” fault and repair
    https://www.youtube.com/watch?v=cH3OUCabVAY

    This is an unusual one. It’s the very hefty LED module out of a streetlight, that has failed prematurely.
    The failure mode is odd. The high open circuit voltage from the universal Xitanium driver has resulted in tracking on the aluminium core PCB, that has progressively burned along a thin copper track, eating right through to the aluminium layer to sustain the tracking current.

    Reply
  16. Tomi Engdahl says:

    Doom ported to the Silicon lab’s MGM210L RF module found in the IKEA TRÅDFRI RGB GU10 light bulb (IKEA model: LED1923R5).
    https://www.youtube.com/watch?v=7ybybf4tJWw

    Reply
  17. Tomi Engdahl says:

    UPDATE: In the github repository we have removed the mip-mapping on composite textures, with no performance penalty, so graphics will be more detailed than what is shown in this video.

    Links:

    Article on next-hack website:
    https://next-hack.com/index.php/2021/

    Article on Hackaday.io:
    https://hackaday.io/project/180182-ha

    Github repo:
    https://github.com/next-hack/MG21DOOM

    Reply
  18. Tomi Engdahl says:

    Hacking a Poundland solar light with intriguing design fault
    https://www.youtube.com/watch?v=zkEuCdPxn98

    The choice of Poundland lights has been disappointing this year so far. That’s not surprising, given the logistics problems caused by the pandemic.

    This is a light they’ve had for a few years, but the style has evolved from time to time. It’s very effective, especially with the neat bit of bubbled plastic light-guide.
    The circuitry has the extra components required to use a colour changing LED, although it runs the LED at such a low current that the lower voltage red LED tends to dominate colours that include red. (magenta, yellow and white)

    It’s actually worth getting these just for the PCB to fix other lights. But you can also hack these to make them single colour, two different colour LEDs wired in series, or add an LED socket as in this video.

    Reply
  19. Tomi Engdahl says:

    LED shock hazards are increasing
    https://www.youtube.com/watch?v=FeKL82V3p-Q

    I’m getting more messages from people who are receiving shocks from faulty LED lights – especially flood lights.
    The problem is caused by internal arcing that occurs in LEDs when they are part of large series strings being driven by high voltage supplies. When the LED fails open circuit it starts to arc and track internally, often causing flickering of the light in the process.

    Because the aluminium substrate LED panels have an extremely thin layer of insulation between the copper and aluminium, it is easy to damage it when an LED burns up, especially the newer directly mounted flip-chip LEDs. This results in a conductive path to the aluminium, which may not be grounded.

    The thin layer of insulation also causes unusual effects when people touch ungrounded LED lights with the switch on the neutral, and the LEDs glow because the person touching the ungrounded light provides a ground path for capacitively coupled current from the LED panel.

    With the high number of improperly grounded LED floodlights coming into the country via direct import or from distributors who have not tested their imported products properly, the risk of shock from outdoor lights (and some indoor lights) is increasing. This introduces a few secondary hazards. A metal fence or structure that the light is mounted to may become live, any shock from a light at height could result in a fall and the effects of rectified DC current leakage may affect the ability of some RCD/GFCI devices to trip, and may also prevent tripping when AC leakage occurs from another fault/shock.

    I’d recommend that extra precautions are taken to fully isolate faulty metal cased LED lights before working on them, and if there is any doubt about the power source then insulated gloves should be worn and work should only be done in dry weather.

    I’d also recommend that the ground integrity of lights is properly tested, and lights with flimsy copper coated aluminium flex have it replaced with something more appropriate if possible.

    It’s best to source new lights from prominent suppliers in your country that have a reputation to uphold. That automatically excludes most eBay and amazon sellers.

    Reply

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