It would definitely have been cheap to replace, but fixing things is like an enjoyable puzzle.

any suggestion to fix if the coil is cut in the transformer of an usb charger ?

+iceberg789 I'm not trying to discourage you, but.... Odds of fixing the fine enameled-copper windings are near nil, unless the break is right at the very end where it joins the terminal. If you can find a near-exact replacement transformer, either new or salvaged from retired equipment, it should be a simple swap operation. The trouble is that you need to know the _exact_ specifications of the _original_ transformer: dimensions, number of windings (usually just primary, secondary, and then feedback and/or bootstrap), voltage ratio (a.k.a. turn or inductance ratio), etc. Sometimes you can get lucky and find the model number on Octopart, but more often than not, they're made in-house and don't have any numbers.

Cut in many places or just the 1? Also, primary or secondary coil?

at the primary side, the ground pin of the transformer doesn't give short sound to any other primary or secondary pins. i guess its a goner.

Is there a preferred solder to use over others? Thanks

@@jeremykemp3782 Yeah, lead based solder is usually the best.

@@Tommyinoz1971 thanks

@@Tommyinoz1971 flux pen?

Last thing you tried?? Lol I personally wouldn't find the fault and carry on looking :)

Haha :)

Of course it is always the last thing you tried! You wouldn't keep looking for a fault after you fixed it! ;)

Absolutely. Better lumen maintenance and reliability than LEDs.

The LED lights in the our house I replaced the switching driver modules with good old 60Hz transformer + bridge + cap. Less efficient yes, but with just 3 parts they're much, much more reliable than modern switchers. They're still working well after many years.

Same

AKA the bench x-ray 😂🤣

I also think showing the actual waveforms on the circuitry like mains, rectified mains, smoothed rectified mains (/with bad cap) and generated switching voltage could help understand the circuitry. I have an old analogue scope myself and it not only (obviously) helped me solve a lot of problems, but also really showed me how stuff is working. Just an idea that just came to my mind: Probably Clive has one too, but maybe an analogue one and can't film it due to the flickering.

Value of the time depend in which part of the world u are. By fixing u reducing electronic waist and there is a job for man who is fixing it.

I laughed more than I should have.

I laughed more than I should have.

LOL

That would have been a lot of red beard coming into frame as Clive got more excited as he was working on the board.....

Some were disappointed, many were relieved. :)

I do plan to "make" some stuff.

For mine I bought a few of those 20A 12V (ish) power supplies off ebay and ran a ton of 12V wire, the smaller ones never seem to last.

It’s really simple to fix you need a item called a glowfix or a yagf Put this in ebay to ebay search bar to see what I mean 293128500853

Being the most simple semi, they tend to be the ones that get the most abuse, and run at mains potential etc which a typical IC never gets close to. Failures of diodes in main low-voltage circuits I'd say are rare.

It would have to be hooked up to its matching LED style. If you used it with lower voltage LEDs it would interpret them as a short circuit and do the pulsing thing for protection.

I bought this off DealExtreme: www.dx.com/p/330ma-9w-led-constant-current-source-power-supply-driver-90-265v-81779#.WMDQNLkrLGI I hooked it up to some COB light bars that I have and it just flashes exactly as in your video. I bought TWO of those supplies above and they both do the same thing. I run the COB lights on another CC supply at 32V 500ma so about 16W or so, do you think that that may be overloading the Chinese 9W supply above? I also have some of those "10W" 'garden' lights like you always show in your videos that only put out about 6W, so maybe I'll try running one of those off that 9W supply and see if it works. Great videos btw, I love LED lighting!

Those power supplies are designed for LED arrays rated for around 30V. What voltage are your COB bars intended for? It may be that they are pulling the voltage too low and causing the driver to shut down. It's possible your other driver is capable of handling the wider voltage range.

I can forward some drivers if you like. They have quite an interesting wee chip that fails. It may be custom to this driver. Took a fair bit of rooting around to find any info on it. Still waiting for the actual speck sheet from manufacturer. Not sure there will be an equivalent.

Exactly. I particularly like it when it says LED lamp cannot be replaced. Challenge accepted!

Same here. If it's broken, I can't make it worth any less to me if I try to fix it. The only thing I lose is my free time, and I can potentially gain knowledge and/or a fixed device in the process. The one exception I have to this is electronics potted in silicone rubber, epoxy resin, or bitumen/asphalt. Potting compounds are just a general pain in the butt to try to extract anything from in an intact or repairable condition unless you want to use chemicals to dissolve them, and those chemicals are generally something you don't want to have to deal with if you can avoid it. Additionally, there is a very good reason the electronics were potted in the first place, usually something such as high voltages (ex. CRT TV flyback transformer/voltage multiplier assembly).

Such items are always worth putting in the toaster oven for a little while. :)

I always see the "Danger High Voltage" as a challenge..

ElfNet Gaming To be honest the high voltages are a secondary concern. Most of the time I'm not going into potted electronics simply because it's such a pain in the ass to get the dang thing apart in the first place! Mains voltages I will mess with no issue, but I'm going to be using the one-hand rule. That's why I have an alligator clip attachment for the test leads on my meter. It allows me to do voltage checks without needing to use both hands. Charged capacitors get the one hand rule, the "chicken stick" treatment, and placing a jumper lead across the capacitors at the first opportunity so they STAY discharged. Certain kinds of capacitors can actually recharge a little bit after being discharged and that can build up enough charge to bite you rather hard if you're messing with something like capacitors recovered from an AED with an expired inspection cert. A "chicken stick" is a jumper lead with one end attached to a length of insulating material, and should probably include a 470k 10w resistor if only so you don't "hard short" the capacitors (that can do some damage some kinds of capacitors even if it doesn't kill them "right then"). I chose a 10w resistor more for flash-over voltage than for actual power dissipation.

Technically speaking you could make a mains voltage LED strobe by charging a capacitor and using a threshold detector to dump the current in a slightly limited manner through LEDs. Like the traditional xenon strobe. Or just use something like a 555 timer chip to drive LEDs from a low voltage supply.

I needed a low volt and did many years ago make a very nice looking us enterprise but I was at the time and later using a 555 timer never able to get anything that looked like a strobe more like a fast blinging! I understand your I would say busy! any ideas would be more then appreciated!

The main things to note about the 7912 regulator is that it is a negative rail regulator as opposed to the more common 7812 which regulates the positive rail. The pinouts are completely different and you have to keep in mind that the metal mounting tab is connected to the middle pin, so if you mount it on a heatsink with other components then the tab may have to be isolated from the heatsink with a suitable insulating kit including the little insulating inserts that go into the holes.

I'm listening to this video on a big mosfet power amp that was taken down by a single bad 1n4004 diode. It took me a bit to track it down, and I'd almost given up hope of fixing it, then I took a shot in the dark and tested the lonely diode. Dead short. 5 min of soldering and Clive's voice is larger than life.

+Chris Richard cool beans!

Oh dear. Now you come along and say ChengX isn't that bad. Well, your name looks like something someone could belive, so I do... The main problem with all this are all the guys that say that everything that isn't japanese (in caps) is garbage :( So no real discussion or even investigation takes place...

"Most 1MW+ wind turbines cannot bootstrap as they require an external power source (the grid, battery bank,diesel generator,etc.) to get to the point where they can produce their own power" For the initial field excitation?

+ New Jersey Bill Yes , field excitation is a part of it but excitation come quite a bit after start up. Powering the up the controllers, the meteorology and wind sensors,control boards,charging the DC bus, slewing into the wind,etc come before excitation and require an external power source.

Ahh, for all the ancillary equipment.

Is the load varying? Is it being dimmed?

Or neutral, or ground, needless to say it's the path for positive voltage to flow to (the neutral wire of the AC). Read up on how a bridge rectifier works to gain a better understanding of his schematic.