Had an LED go out in the bathroom over the vanity. Decided to do some testing on it. After determining that it wasn't a poor electrical connection I broke it open. Found a very cheap set of electronics inside. Nothing like the better made PWM type lights.
View attachment 340374
View attachment 340375

This is the second cheapest construction of a driver that I've seen so far. The only worse things I've seen have been those cheap Chinesium made which have hardly more than a capacitor for voltage drop.

Anyway, the next two pictures focus on R13 (F1). When examined, it looked like a broken solder joint. Only it wasn't. The other side of R13 (F1) looked good but IT was the side that was open. Now, given that these are heat sink mounted it's not easy to solder on. But I managed to set the iron at its hottest and let the iron dwell on the joint for quite a few seconds. Maybe on the order of 20 to 30 seconds. But eventually solder began to bridge from R13 to the pad. You can clearly see the end that I resoldered. And yes, that's WAY too much solder. But that's what it took to transfer sufficient thermal energy to get the pad to flow.

View attachment 340376

View attachment 340377

You may also note the pinch type wire junctions of both the Hot/Neutral lines and Capacitor (mounted through the board). If this is the reason why these things are coming down in price then we can begin to expect more failures in the future. After the butcher job - I mean solder job - it's working. Now, what to use it for?

What do you want to say other than “cheap” & “poor design”? How should it be to be a good design? Good designs need not be “expensive”.

 

I have a few LED lamps not working. Just a week ago I popped off the cover of a flood lamp and found one LED that was open. I shorted across the LED with a 1kΩ SMD resistor and there was light.

 

"Good Design" often includes things like assuring that the circuit layout will provide adequate solder connections. A larger connection pad could have allowed a bit more solder in the connection. But poor assembly is more the responsibility of the production group, so it was mostly poor assembly, not so much cheap design.

 

Seems like MY bulb is quite common and the apparent state of the art. Or maybe not - what do I know ? !

Here's the thing: I'm learning more and more as I look further and further into these things. I came across this video as a result of YT making viewing selections. Enjoy.

 

Put it in the trash where it belongs, I just don't understand why people spend so much energy trying to use the junk they accumulate.

You learned something, now move on.

Because they can.

Why did "we" go from a simply piece of tunsten wire in vac'd glass bulb to heavy metals/plastic/chemicals LED bulbs? The old tungsten bulbs lasted way way longer, were way cheap to buy, and didn't pollute the landfills.

Sometimes the great ideas are themselves wrapped in a "junk" envelope.

 

OK, "DCK", I have the answer to that question: It is not about :The old tungsten bulbs lasted way way longer, were way cheap to buy, and didn't pollute the landfills, but rather about making the present products obsolete, for the purpose of profit. The advent and mandate for digital TV was not to improve the quality of the programs by higher resolution, it was about making every television produced since about 1950 suddenly obsolete and totally unusable. The higher resolution available only matters for programs recorded at the higher resolution, it does nothing for the millions of rerun programs. The ability to transmit more programming in the same bandwidth is a great byproduct, but does it really benefit any of us??

 

So transistors and ICs are just a profit margin over perfectly adequate vacuum tubes?

 

The Bright Power chip is a modern linear regulator chip that works quite well. You might want to watch of of BigClivedotcom's videos on YouTube where he's analyzed a large number of LED bulbs. On some of these chips, 2 resistors in parallel set the current through the LEDs. In many designs, it's like it was made for hacking. Often, the resistors are about a 2:1 ratio. Removing the higher value resistor reduces the current through the LEDs by about ⅓, resulting in a slightly dimmer bulb that will run cooler with a much longer life. Removing the lower value resistor instead reduces the current by maybe ⅔, resulting in even a dimmer but far longer life bulb.

Those push-in contacts for line power and the cap are quite effective. In fact, I've never seen one fail. They provide some isolation from heat for the cap as well.

Why would the manufacturer use the push ins? They seem very expensive with respect to a solder pad and solder.

 

Put it in the trash where it belongs, I just don't understand why people spend so much energy trying to use the junk they accumulate.

You learned something, now move on.

Ya never know when you're gonna need this. The day after you throw it out!

 

Actually, solid state devices

So transistors and ICs are just a profit margin over perfectly adequate vacuum tubes?

The development of transistors, and then integrated circuits did provide a serious increase in capabilities. And they were the result of a lot of serious development and increased knowledge.
There is no comparison between the development of solid state devices and the change-over to digital TV broadcasting.

And I have no pity for those who see no reason to keep whatever they do not need at that moment. The future is seldom known, but only presumed.
The reality is that we do not always know exactly what will be happening tomorrow and exactly what we will need. It often is more fun that way.
But I do pity those few folks who in such a rut that they do know exactly everything that will be needed the next day.

 

Why would the manufacturer use the push ins? They seem very expensive with respect to a solder pad and solder.

Expensive? I doubt it. The contacts add virtually nothing to the cost of circuit board. The circuit boards are built by the millions. Compare the physical size of a flat board where the LEDs are the tallest thing to a more fragile board with a cap sticking out of it.

When it's time to assemble bulbs, pull a board from the tray, poke in a cap and poke in the pigtail power leads from the socket. A low-skill task that takes literally seconds.

And of course there's the aforementioned ideal of giving some thermal isolation between the cap and the aluminum pcb.

 

Had an LED go out in the bathroom over the vanity. Decided to do some testing on it. After determining that it wasn't a poor electrical connection I broke it open. Found a very cheap set of electronics inside. Nothing like the better made PWM type lights.
View attachment 340374
View attachment 340375

This is the second cheapest construction of a driver that I've seen so far. The only worse things I've seen have been those cheap Chinesium made which have hardly more than a capacitor for voltage drop.

Anyway, the next two pictures focus on R13 (F1). When examined, it looked like a broken solder joint. Only it wasn't. The other side of R13 (F1) looked good but IT was the side that was open. Now, given that these are heat sink mounted it's not easy to solder on. But I managed to set the iron at its hottest and let the iron dwell on the joint for quite a few seconds. Maybe on the order of 20 to 30 seconds. But eventually solder began to bridge from R13 to the pad. You can clearly see the end that I resoldered. And yes, that's WAY too much solder. But that's what it took to transfer sufficient thermal energy to get the pad to flow.

View attachment 340376

View attachment 340377

You may also note the pinch type wire junctions of both the Hot/Neutral lines and Capacitor (mounted through the board). If this is the reason why these things are coming down in price then we can begin to expect more failures in the future. After the butcher job - I mean solder job - it's working. Now, what to use it for?

Nice job nonetheless. Use it to light something up, what else

 

Because they can.

Why did "we" go from a simply piece of tunsten wire in vac'd glass bulb to heavy metals/plastic/chemicals LED bulbs? The old tungsten bulbs lasted way way longer, were way cheap to buy, and didn't pollute the landfills.

Sometimes the great ideas are themselves wrapped in a "junk" envelope.

Hi,

Did you just say that the old tungsten bulbs lasted way way longer than LED bulbs.
What kind of crappy LED bulbs are you buying anyway?

 

Nice job nonetheless. Use it to light something up, what else

Yeah - eh - not so much so. This has been more of a learning project than anything else. I COULD use it to do what it was designed for - to light something up - but then there's the exposed circuitry. I wouldn't want to put myself or others in danger of a nasty shocking.

I made the statement that I found a cheap made circuit - not knowing how prevalent this type of circuit and control has become. I've taken older bulbs apart and found a whole PWM (or something) that modified the incoming power to something designed to light the LED's as they sit. I took one of those older LED plates (ring of LED's) and tried to power it with DC power but my supply was not able to light them. I didn't know at the time that the circuitry could be producing much higher voltages than I would have suspected. I've taken several of them apart thus far. And have yet to find a practical use for something I've taken apart. Like I said it's all about curiosity and about learning something new. I now realize I have access to a current controller chip. Just what I might use it for in the future is anyones guess.

 

Yeah - eh - not so much so. This has been more of a learning project than anything else. I COULD use it to do what it was designed for - to light something up - but then there's the exposed circuitry. I wouldn't want to put myself or others in danger of a nasty shocking.

I made the statement that I found a cheap made circuit - not knowing how prevalent this type of circuit and control has become. I've taken older bulbs apart and found a whole PWM (or something) that modified the incoming power to something designed to light the LED's as they sit. I took one of those older LED plates (ring of LED's) and tried to power it with DC power but my supply was not able to light them. I didn't know at the time that the circuitry could be producing much higher voltages than I would have suspected. I've taken several of them apart thus far. And have yet to find a practical use for something I've taken apart. Like I said it's all about curiosity and about learning something new. I now realize I have access to a current controller chip. Just what I might use it for in the future is anyones guess.

Hi,

Well I am sure you are smart enough to figure out how to put it back together in order to make it safe again, but it's up to you. I don't bother fixing these things I just buy new ones and get something like a package of four for some reasonable price.

It is up to you but you could try some high temperature epoxy, or just hold onto it for future use.

 

you could try some high temperature epoxy, or just hold onto it for future use.

Could try rebuilding the thing. But like I said - there really isn't a specific use for it now. It'll probably clutter up my already cluttered work bench. Eventually I'll get around to tossing stuff out. I do that about once every 10 years.