3W High Power E27 Warm White Focus 3 LED Spot Lamp Energy Saving 165-245V (WHL #8)
Slightly aged review item today!
Last week, an E27 LED light bulb died. I bought it back in September 2012 for 2.58 GBP on eBay and got a full refund at that time because it was neither “3W” nor “Warm White”, so I decided to use it in a bedside lamp which isn’t in use much at all. Now, 4 years or let’s say 300 hours of operation later, it showed a nasty 50 Hz mains flickering and I decided to replace it with a 3W quality German brand lamp for… 2.59 Euros. LEDs really have entered the mainstream!
Now back to the Wan Hung Lo lamp. To quote the seller’s response in that refund dispute:
Thanks for your email. Sorry to make you disappointed.
No need the picture, I believe you.
(“I know I sell crap”)
You see, this bulb is very cheap,you can not expect the quality is as good as the bulb who made by a professional manufacturers.
To show our apologize, I think we can issue you a full refund, how do you think so?
(I did very much think so. Yet it wasn’t by far the cheapest lamp at that time, I chose it because of the much more massive heat sink compared to the real cheapos. Well, at least on the product pics)
The original unit had a plastic optics thingy on it, which produced a blue spot in the center and a green ring on the outside. God knows how cheap you have to go in sourcing material that produces this effect, but without the lens it was fine, so I decided to run it without (bare LEDs and wiring exposed). I don’t have any pets or toddlers that would touch that when in operation, and if I did myself, well, whom to blame.
So, here’s the pile of crap from the outside:
As you can see, the heat sink isn’t moulded properly and very thin. The three screw holes on the top would hold the lens, and another three screws hold down the LED plate, which is basically a piece of round aluminium (as heat sink, not too bad) and a plastic PCB similar to those on LED strips. The LEDs are in fact 1W types, but the driver does not deliver enough current to run them at 1W each.
The insides did fall out with some force applied on the green plastic ring, but (shocker!) the base contact is just screwed in place. More of a shocker, the lead from there wasn’t attached by any means – it was just held in place by pressure when the gal in the Wan Hung Lo factory screwed on the base contact. Wiggle it loose and it would go anywhere, what could possibly go wrong.
Even more 8O: Look at the wire diameter. 7 strands of thickened copper-free air. The heck, this cable is running mains voltage! I’ve added 0.75mm² for comparison, which is half of the minimal diameter that may be used for electrical installations in Germany. 1.5mm² is for lighting and other low-power stuff, 2.5mm² is recommended for most installations (especially wall plugs, required for 3-phase stoves and the like).
The driver circuit is very basic — two electrolytic caps (“Y.J.H” “brand with 400V/3.3µF and “Jwco” “brand” with 25V/22µF), one run-of-the-mill “13002” transistor from “SLT”, an UF4004 diode, a small transformer block and some SMD hen food. Isolation slots? Nope. More than 1mm isolation distance for the mains stuff? Nope, who would need that. Fuses?
One of the diodes of the half-bridge (that’ll do!) rectifier has gone way up in threshold value, maybe this caused the driver to fail. I however also checked the mains cap which had a little bulge. It had a very strange reading on my transistor tester, between 3000pF and 9000pF…which is still 3 order of magnitude too small for the 3.3µF = 3300nF nominal capacity. Reading was dependent on orientation, so something was even more fishy. I opened up the aluminium can and unrolled the cap, which to my surprise wasn’t even completely dry. But it had several pieces of aluminium foil inside, every single one with different length, half of the cap had no foil at all, and the individual pieces weren’t connected either (the pin connected to the outside fell right off as well and didn’t pierce the entire length of paper). So I deem this was a factory
reject quality product from the very beginning and I’m not sure how it worked for such a long time at all.
And speaking of longevity: Look at the copious amounts of thermal …toothpaste? that they drowned the unit in:
Well, glad this pile of Wan Hung Lo quality didn’t burn down my house a long time ago. Now it’s replaced with a Müller Light LED bulb which outperforms the intermediate 27W halogen bulb and of course this one. The unit shown will be dismantled and recycled as far as possible, the LEDs are still good for experiments.
Next up: Qualitty Lenovo power jacks and plugs.