A look at the circuitry inside a cheap bluetooth speaker that screws into a standard lampholder.
The quality of construction suggests that it's a highly evolved product. They've managed to fit the whole circuit on a single sided PCB which is quite a feat.
The only thing that lets the unit down is what appears to be an incorrect remote control that has been supplied with it.
Although I unclipped the front cover, it appears to be fitted with a bayonet cap arrangement and just pops apart when the front is twisted slightly. (Potentially exposing live connections inside.)
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
#ElectronicsCreators

A cheap and surprisingly dysfunctional led lamp with built-in bluetooth speaker from ebay. Let me screw this in, but when i screw it in, it is going to go through stroby color sequences just be aware of that, but it's not that bright anyway, so it doesn't really matter. It's more sort of novelty. There we go.

This is the remote control that came with it. I put the bad pulled the little battery tab out. Nothing worked so i checked the battery was in there. Nothing worked.

I changed the battery. Nothing worked. I found that sometimes that it will work and sometimes it won't, but the one button that does work is fade here which selects fade, but the other ones like you can't pick single colors. Fortunately, this completely random similar looking remote does, if you stagger all the buttons, then this one does do red green blue, you don't get white and it does do the on off.

It also does the effects that it goes through various sequences, but anyway, let's put it to a fixed, color and uh. I shall play some music and we'll hear how it sounds. One moment please and it does work. It has strange audio artifacts at times and it does uh.

When you select this one, it does seem to pause with strange, purring noises and start again and uh. You can also skip back report videos if it works right. Tell you what i shall stop the music one moment please, the music is stopped. Let's remove the speaker.

I can't really think of any other things to do with this. Let's try and spudger open. I assume it just clips together we shall find out. I shall ram the spudger into it and see if we can make it split apart with loud cracking noise as soon as it's not glued, i see what appears to be a clip here.

Well, actually that made a loud crunching noise. So, okay, oh, not bad inside, not bad inside! Quite a big speaker, i have to say surprisingly big speaker um and a circuit board that looks multi-function. I'm looking at that little i'm guessing that this little chip here will, let me just uh zoom down. This will tell you what i shall get the circuit board out and take a picture of it, and then we can explore.

What's on it. One moment please interesting circuit board, not least because it's single-sided they've done very well to do that. They have cheated at one small point, but it's not bad. It has two connectors in the back.

The red one is for power and the white one is for the speaker here is the speaker, and here is the power supply, which is a little semi, isolated module. I should just short that with my fingers, i'm going to get a shock i'll, get it when i, when i expect it uh and it's a 5v power supply, although i measured 4.5 volts in the circuit board, i don't know if that was being pulled down by The load of the leds - it's not really designed to illuminate a room. This is quite a low power device. The way they've done the leds is they're all a parallel array.

So if i show you the back of the circuit board, you can see well i'll zoom down a bit. You can see that the tracks going to each led just basically snake backwards and forwards all the way around to leds and there's a start point here and an end point here and the reason it didn't light weight when i use the remote control was because the Common positive track, this kind of sawtooth one here is matched by a negative the outside for the missing white leds. It turns out that they can either control rgb, leds or potentially both spores, but also the fairly high power of white ones around the outside. That are just wired in parallel again and the transistor for them is here and the resistor is there uh? I meant to look at what those y1 transistors are they're, being driven directly from the microcontroller makes me think it might be mosfets, not sure, i'm just going to check that right now.
One moment please nope, it's not a mosfet, it's a standard, npn transistor. That is being driven directly from the pins these, so they must have some sort of current limiting built in the chip may well be dedicated purely to controlling lights and controlling the amplifier with the the music. So here's the antenna for the bluetooth chip and there's its crystal um, the other resist the other transistors and resistors for the leds. The other colors are over here.

We've got 7.5 ohm, 4.3 ohm and 5.1 ohm um. The supply coming in goes to the chip via a 3.3 ohm resistor and there's a decoupling capacitor next to it. That's, presumably just to provide at least some filtering. The chip then sends a signal over to the amplifier, which is the ns8002a three watt amplifier, and this is a 50 amplifier and here's the data sheet for it.

I shall zoom down a bit in this. It's a very straightforward amplifier. It seems to be very, very common: it's cheap! It's basically like two high current op amps that can drive the speaker directly and the both the positive inputs to the op amps have a decoupling capacitor to ground, and they also have a divider based on 200k internal resistors that bias those to the midpoint position. The input then um has a capacitor and resistor, and that resistor and this negative feedback resistor here, will set the gain of the amplifier.

I've not really investigated this too much. I did find a data sheet. It was in chinese. This little arrangement here is to make the other amplifier go in the opposite direction.

So when this one's going positive, there's no go negative and vice versa, and it just means it can actually drive, because it can drive the speaker positive, negative and negative positive. It gives a much wider voltage range effect. It makes it louder, it's the equivalent of bridging amplifiers, very simple. It also this input here.

The sd input appears to be uh disabled and i think it is actually used by the chip, so it can actually mute the amplifier when it's not used. Is there much else to say about this? The infrared uh sensor has its own decoupling capacitors over there, as they always do just because it is a fairly sensitive device uh after that, that's it so pericomion, bluetooth, chip, um, amplifier, infrared receiver and leds switched by one two, three transistors. That is fundamentally it something they've done here, which is quite neat to keep. This single-sided circuit board simpler, they've jumped the negative through under the chip and to do that.
They've not put pads down for the pins or for two of the pins and what they've actually done is they've printed. The black screen print ink on the top in that area, just as extra insulation, so the pins of the chip can actually come in contact with that uh negative. This capacity underneath it's quite neat very neat. How they've actually managed to compress it all into that simple design? I don't know what these pads are for, because it might be another design.

One of them is connected to positive. The other is just not connected at all, but that's it. It works. It doesn't work that well, it's got it's, it's got its problems uh, particularly with the remote control, but then again that's just sometimes what you get.

It's certainly an interesting device, and the case is usable and suppose the circuitry is relatively usable. If you perhaps want to put a bigger speaker on and just use it as a bluetooth receiver, but it's quite neat: it's okay! It's pretty amazing what they can do with such a small amount of components.

17 thoughts on “Inside a bluetooth speaker bulb”
  1. Avataaar/Circle Created with python_avatars Rhodexa's Arts says:

    It's surprising how the Chinese put BT speakers on everything.

    I've seen them in headphones (normal, stuff), fidge spinners, rc cars, kid toys, lamps, wrist bands, lil plastic cubes (less then 2cm wide), flashlights, stuffed animals… and much much more

  2. Avataaar/Circle Created with python_avatars Mike Houghton Gaming says:

    side topic. I am now dreaming about. You were saying something like why you should never and a component in your hand starts to smoke (looks like a resistor) and you say this is why you shouldn't do this.

  3. Avataaar/Circle Created with python_avatars Will Deit says:

    Hi Clive, Just had a PCB creating idea from Instructables : Make High Quality PCB's With a Cheap Laser Module It seems a great one I thought you might be interested in.

  4. Avataaar/Circle Created with python_avatars Bong Jovi says:

    I think if you can link the speakers together to create a sort of shitty quadraphonic sound, I'd probably buy them. Right now I'm using the Geeni LED lights and they're pretty sweet, like a poor man's phillips hue.

  5. Avataaar/Circle Created with python_avatars Yorkshire Rose says:

    Just what you want for a little light music!

    Yeah…. It'll take a lot to wean me off my 30W per channel amplifier and bass reflex speakers – Even my "Juice" soundbar can't come remotely near the sound quality I expect – Imagine trying to listen to the big 'boomy' voice of our Clive on that little lamp!

    On the other hand, in a trendy teenager's bedroom, I guess this lamp might just sound a tad better than the speaker in a mobile phone?

  6. Avataaar/Circle Created with python_avatars Landon Brainard says:

    BIG CLIVE! Iโ€™ve been getting interested in watches recently. I came across a model from the late 60s, early 70s called โ€œAccutronโ€. Do you think youโ€™d be able to do a reverse engineer of it? Itโ€™s very unusual in the world of electric watches as it doesnโ€™t have a quartz clock but still manages to keep time with electric parts.

  7. Avataaar/Circle Created with python_avatars Jason Kuehl says:

    I've seen these at one of the local big box stores. I'm waiting for ones with the "personal assistant" type services installed, though. I think it would be great to have LED bulbs that actually talk back for a change. ๐Ÿ˜†๐Ÿ˜†

  8. Avataaar/Circle Created with python_avatars John Henry says:

    I've had one (different brand/model) for about 5 years now. Uses a phone app to control everything. Showed it off twice but never use it. Has decent sound but is on a shelf now collecting dust.

  9. Avataaar/Circle Created with python_avatars greenaum says:

    Had to happen. They will put Bluetooth speakers into absolutely anything. They will put RGB LEDs into absolutely anything. So why not put a Bluetooth speaker into some RGB LEDs? Had to happen!

    Wouldn't wanna guess at the size of the cap dropper in that, but here goes…

  10. Avataaar/Circle Created with python_avatars Franรงois-Marie de Jouvencel says:

    Ha this kind of remote controller is everywhere they all work more or less the same. I'd be quite interested in a video showing how to modify one such controller to do things like control the color precisely instead of using one of the presets.

    I have a lamp I made with 6 led light bulbs in parallel all controlled by a remote like that and sometimes when I change the color one or two bulbs stay on the previous color setting, it gives a very nice effect. I'd like to be able to control it somehow.

  11. Avataaar/Circle Created with python_avatars แ›‹แ›’แ›–โ€แšฑแšซแ›žแšปแ› says:

    The only use I can think of for this might be in a lamp on a night stand by your bed. Then you have a little light and a little speaker to put an audiobook or something on to fall asleep to. Since they're cramming stuff in there they should put a usb out so you can always have a phone charger by your bed as well.

  12. Avataaar/Circle Created with python_avatars rbtreziok says:

    Clive, just got a couple different arc lighters to try out. They've got some sketchy high voltage going on… Seems like good teardown material

  13. Avataaar/Circle Created with python_avatars Fluffy Blue says:

    The sound from this unit reminded me of a 90's speakerphone, playing the hold music of a servicedesk line of an internet provider. Sounded awful.
    The light from this unit… well, there wasn't any. It looked like a coloured piece of plastic.
    It's appalling. People should not buy this crap. If it doesn't get bought, it won't be produced.

  14. Avataaar/Circle Created with python_avatars Mark Clark says:

    A Multi-functional Tester-TC1 align the infrared remote control with the "IR" light, then press the button in the remote control, if the detector successfully decode it, it will display the data code and infrared wave form.

  15. Avataaar/Circle Created with python_avatars Dr.Andy Hill says:

    Not a bad little thing.
    I take it this was filmed before your ill-fated trip to Glasgow, hope you continue to improve and quickly fully recover.

  16. Avataaar/Circle Created with python_avatars Actuallyusingmy Realnamehereguys says:

    I bought a couple of bog standard colour changing bulbs recently, the dark blue setting is great for a good nights sleep with just enough light to find the loo without waking everyone up ๐Ÿ™‚

  17. Avataaar/Circle Created with python_avatars T Stuart says:

    I have just purchased a 5m length of LED strip lights. The remote had the same problem. If you take away the button membrane key there are total rubbish cheapest to the cheap. Needless to say the 5m LED strip failed after a few hours.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.