15W E27 224-LED 6000K 1000-Lumen Energy Saving Light Bulb - White (180~240V)

Pros: I tested the electrical characteristics of the 224 LED bulb I recently bought from DX. The 220-vac bulb tested 57 ma ac current at 238 volts ac input voltage, which computes to about 13.6 watts used. Over a period of a few minutes the current rose from an initial value of 56.6 ma to the final 57.0 ma. In an otherwise darkened room, about a meter from a 75-watt clear incandescent bulb, the 13.6 watt LED bulb appeared as bright (or brighter) subjectively than the 75 watt incandescent. The LED appeared a “bluish-cool,” whereas the incandescent was an “orangey-warm.”

Cons: The 224 LEDs are listed at a rated voltage of 180vac – 240vac. That could be interpreted as the upper voltage range limit before destruction, or it could be their actual operating voltage. This is not stated clearly and will lead to much confusion in lower voltage countries. Actually, it turns out to be the operating ac voltage range, 220-vac nominal. Our normal house voltage in the US is 110-vac, with 220-vac only prewired/hardwired for a few big appliances: clothes driers, air conditioners, and electric ranges. It would be very difficult to rewire a typical house for 220-vac. And if you just changed it overall in the power distribution box (circuit breaker box) for the existing house circuits, which would be easy, all the other (110-vac) things plugged into those circuits besides 220-vac bulbs would be destroyed. Some of the forums on this site now have complaints from others in the US that DX should include the 110-vac version for sale. The US/Canadian socket for 110-vac bulbs is an E26. E for Edison and 26 mm diameter. The UK and European (and 80% of the planet) socket for bulbs is E27 / 220-vac. The fact that E26 and E27 sockets are so close in diameter also adds to the confusion. It is easy to fit 110-vac bulbs and/or 220-vac bulbs into either socket because they are so close in size. That’s what made it so confusing initially.

Other: Difficult to use in the US. But on 220-vac it is a great product. So I will be ordering a few more soon, but just for my recently rewired 220-vac workshop. Big advantages: efficiency and cost.

Pros: Excellent light output. At 238-vac it is at least equal to a 75w incandescent, maybe close to 100w equivalent.

Cons: But that poses a problem. At 238-vac (I'm near the power distribution transformer) the voltage is a bit too high, as well as the resulting current, 57 ma. The nominal life of the bulb is rated very long. But, forcing the brightness with this much over the nominal 220-vac likely will lead to a short life. An approximate 20 volt drop is needed from 238 volts I have.

Other: Fine tune higher-than-nominal voltages to get best life from the bulb. Too bad the manufacturer does not provide a curve (through DX) of bulb life versus applied voltage. Manufacturer, do you get the hint?

Pros: With 337 ohms (measured) in series, the following were measured: source voltage = 238-vac, voltage across resistor = 16.7 volts, lamp voltage = 222-vac.
The above minor voltage differences attributed to rounding to closest integers on high scale and to heating of resistor during measurement.
Calculated current from above = 49.55 ma. Calculated total heat power given off by resistors = 0.83 watts. [2 - 1/2 w resistors in parallel "should" handle 1 watt!]

Cons: Resistors were noticeably HOT. At a combined 1 watt rating this is intolerable.
Therefore, if you try this, do not buy your resistors at Radio Shack. They are obviously overrated on power handling capacity.

Other: Still looked like a very bright bulb, at ~nominal voltage rating.

Pros: The need for a wirewound power resistor in series in case of a little overvoltage (~225 to 240) from 220 nominal should result in a longer lifetime for bulb.

Cons: Hard to find such big resistors at reasonable prices.

Other: It's a small expense to put series resistor(s) in an AC junction box, where needed, to extend bulb life to the hopeful 50,000+ hours advertised.

Pros: All three bulbs working, in parallel. Brightness each at least as good as 70w incandescent. Very slightly lukewarm with hand wrapped around one after 15 minutes On.

Cons: Wasting a little energy in dropping resistance. Resistance is two nominal 300 ohms (10w rating each) in parallel. Should be capable of handling 20w combined, albeit it is very hot to the touch.

Other: Great bulbs. Overvoltage should and can be corrected. Cool, bluish light.

Pros: Experimentally determined operating point of LED at about 7 ma and 6 volts. Light ouput bright and reverse current in single digit uA range.

Cons: I need another important data point at 6 volts. The inflection point was inferred from 10 watts/224 LEDS > approximate runaway point.

Other: Not hard to figure out approximate curve, but I need to get a 4 - D cell holder to verify the 6 volt current.

Pros: Disassembly proceeding. The side circuit boards appear all the same, with a simple series parallel connection of LEDs.

Cons: The top circuit board is a complex assortment of various series parallel connections of LEDs. I will be posting an updated, and annotated, version of the top circuit board. If posted, you will see eight sets of two rectangular ovals each. Four of these have connections to the sides as well as mechanical supports, the other four (inter-spaced with the first 4) are just mechanical connections. If not posted, "A" starts at about "3:15 o'clock" and proceeds CC to end at "P" at about "4 o'clock." These will be helpful later as circuit tracing is possible.

Other: It is possible to connect these LEDs as simple parallel combinations. I sliced the copper from parts of the top board and reconnected in simple parallel style and am now running at 3.2 volts and 220 ma total for the 33 LEDs of the top circuit board. Bright.

Pros: Uploaded more pictures.

Cons: I may have accidentally interchanged bottom and top board captions. If so, that's easily seen and corrected. The top board has only LEDs on one side and not much on bottom. The top board has components on both sides.

Other: I suppose it's possible to trace this circuit (I will document the components) and reconfigure for 110 vac. But reconnecting, as sold, is beyond my soldering ability! So, I will be reconnecting as a simple parallel 224 LED. BTW 33 (on top circle) + [8 x 24] (sides) = 33 + 192 = 225. Two Twenty FIVE. Not 224??

Pros: Pictures of bottom and top of bottom board came out nicely. The black (stand-up) capacitor is marked 10 uF. Four diodes, maybe a full wave bridge rectifier? All resistors measured [but may have read somewhat low since they are in parallel with other parts of circuit]: R1 = 470K (color bands hard to verify), R2 = 1.1 ohms, R3 = 463K (again, the bands are hard to see - the colors), R4 = 10.0 ohms.

Cons: The other three brown capacitors (all 3 in parallel) are not marked.

Other: If you diligent folks out there want to trace out the circuit board, etc and come up with an overall circuit, go to it! Younger eyes/phyches may be better able to cope with the maze. For me, I will rebuild at base voltage dc using a BIG power cube to power from 110vac; power cube being something like 6vdc, 2A output to 224/225? LEDS.

Pros: I will be uploading how the base looks from the top inside. The red wire goes to the center pin on the shell, and the white wire goes to the outer shell connection to the 220 vac.

Cons: TYPOs keep creeping in about bottom and top circuit boards!

Other: I will have data points for voltage versus current on typical LEDs in this thing in a few days.