This is a very simple LED lamp designed for decorative, sign and festoon use. It has one of the lowest component counts I've seen, and uses the higher voltage multi-chip LEDs to allow a very basic resistive current limiter.
Each of the four LEDs has six LED chips in it to give the equivalent of a 24 LED string. If they'd used the 12 chip version of the LEDs it would have increased the efficiency, and a very low value capacitor could have been used to remove the slight 100/120Hz flicker.
The low power and minimalist circuitry means that these lamps should be extremely reliable.
Although designed for 220-240V use, the lamps should work on 100V upwards at lower intensity.
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 algorithm quirks, allowing it to be a bit more dangerous and naughty.
#ElectronicsCreators
Each of the four LEDs has six LED chips in it to give the equivalent of a 24 LED string. If they'd used the 12 chip version of the LEDs it would have increased the efficiency, and a very low value capacitor could have been used to remove the slight 100/120Hz flicker.
The low power and minimalist circuitry means that these lamps should be extremely reliable.
Although designed for 220-240V use, the lamps should work on 100V upwards at lower intensity.
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 algorithm quirks, allowing it to be a bit more dangerous and naughty.
#ElectronicsCreators
A while ago, I was sent a picture of the inside of one of these LED lamps. It's a typical golf ball style lamp that is used in decorative light fittings or the outdoor for students. And what's interesting about it is that it's got this little circuit board inside it and it's got the absolute most simplest circuit possible for an LED lamp. Let me show you a close-up of the circuit board.
On the circuit board, we have the mains incoming Supply going to the AC input of a bridge right far. The output then goes via two resistors through four LEDs but each of these LEDs is actually six LEDs per package. So if I show you the schematic for this and I'll Zoom down this little bit, there's an incoming Supply There's a bridge right far, there's a two resistors and there's the LEDs. So the six LEDs per package for a total of 24 LEDs It gives about 66.4 volts across all the LEDs so they are dissipating about 0.33 Watts at the five milliamp current that's flowing through the circuit.
However, the 215 key resistors are both dissipating more power resistor than the LEDs, so it'd be quite nice as increasing the number of chips and LEDs. They could have used the 12 LED chips or they could have just added some more in because there is room there. They could have added a small Arc of LEDs in here and that would have lowered the dissipation across these resistors. The other thing they could have done is they could have added a very small electrolytic capacitor across the output the bridge rectifier, but something even like one microfard 400 volt would have been all that it would have taken at this occurrent to smooth that and get rid of the Ripple that would have potentially increased the voltage across the circuit, but if they'd had more uh LEDs in there, that would have compensated for that.
And also they do have the option they could. there's plenty of space. They could have added more resistors in here. they could have added one, two, three, four.
It's not a super cramped design and that would really have got rid of that flicker at the moment though. The circuitry is very, very simple. my idea of where they could put the capacitor. they could have put a couple of pads here connected directly to the output the bridge right far and they could have laid the capacitor across the top of that because none of this is really going to get very hot except the resistors themselves which will get quite warm because of their dissipation.
But our interesting lamp, it does have that slight Shimmer as a result of not having the smoothing, but uh, other than that, you know it's not that bad and it's very, very simple. It's got a newer Unity power factor, the voltage and current, and good sink and it is just manufactured to be a cheap, simple lamp. but it does have scope for improvement in the future.
That would dim nicely, albeit with a lot of flicker. I would place a capacitor across the LED string rather than the recifier.
Maybe even small smd capacitor across the output of that bridge rectifier?
I don't know their voltage ratings or capacity though.
Very cute
I have no idea what you are talking about, but I can listen to you for hours.
I love how we've gone full circle. We made LEDs to be better than incandescent bulbs which are basically resistors on fire, and then we put resistors on fire next to the LED's.
Who cares about the power factor? The power company that's who, it is their problem. Ron W4BIN
Instead, they could have done away with the resistors on the "DC" side entirely and then used a capacitive dropper + resistor on the AC side of the bridge to reduce heat.
I really can´t stand the flickering light unfiltered LED lamps give. it´s like playing a game on a 60Hz CRT in comparison. you get tired in the eyes. I know the bulb gonna flicker twice the speed but some way it is more pronounced when the light is all off and all on and none in between so I just give a comparison there ;P
Clive, why not do a video showing how you would implement your improvements on the bulb you have now. I'd be interested to see how you modify it yourself.
can one, or two, help explain µF & nF differents? What the bleep am i not getting
Those LED lamps have an efficiency, that is almost as bad (maybe worse, if the more complicated construction and the need for more (and more exotic) materials is concerned) as an incandescent lamp. What a waste.