Quite an odd style of lamp. Really attractive design both in terms of appearance and the technical construction, but the use of a single tiny LED emitter in a lamp rated 5W just didn't inspire me with confidence regarding the potential longevity of the lamp.
I bought it from a retail outlet called BM Homestores who normally stock more generic stuff, so it was odd to see them stocking a fairly high profile brand like Osram. I'm a bit suspicious that they might have been selling off lamps that hadn't quite met the expectations of the designers in terms of thermal dissipation.
Light output was quite a hotspot as you might guess from a single sharp point source, but didn't really seem to pack the punch that I expected a 5W lamp to achieve. I was working on a show at the time so I didn't have access to a power meter to test the actual power consumption.
The construction is actually really pleasing. There's a front coated-aluminium heatsink body and a separate clip-in electronics housing at the back that took a fair amount of force to get out.
The LED is on an aluminium substrate board with what I think is a Schottky rectifier and a 1K resistor in parallel with the LED, possibly to ensure complete extinguishing quickly when turned off.
The oddly shaped LED PCB has standard white heatsink compound and is a very specific fit into the housing, and is then held in place by a plastic lens that has thrree latching prongs and pillars that mate with and alighn the PCB to press it onto the main heatsink.
The power supply uses a chip called an LNK606GG and it appears to be a standard 5.5W switching supply controller for either mains adaptors or in this case a current regulated supply to the LED. An oddity with the design was a wire that appeared to come directly from the windings of the transformer to the rectifier diode on the LED PCB, with two wires coming back from the LED for the common and smoothing of the rectified voltage.
As I say, a really attractive and nicely engineered lamp, but the tiny single point 5W emitter doesn't make me feel comfortable. I just prefer my LEDs to be kept as cool as possible.
I bought it from a retail outlet called BM Homestores who normally stock more generic stuff, so it was odd to see them stocking a fairly high profile brand like Osram. I'm a bit suspicious that they might have been selling off lamps that hadn't quite met the expectations of the designers in terms of thermal dissipation.
Light output was quite a hotspot as you might guess from a single sharp point source, but didn't really seem to pack the punch that I expected a 5W lamp to achieve. I was working on a show at the time so I didn't have access to a power meter to test the actual power consumption.
The construction is actually really pleasing. There's a front coated-aluminium heatsink body and a separate clip-in electronics housing at the back that took a fair amount of force to get out.
The LED is on an aluminium substrate board with what I think is a Schottky rectifier and a 1K resistor in parallel with the LED, possibly to ensure complete extinguishing quickly when turned off.
The oddly shaped LED PCB has standard white heatsink compound and is a very specific fit into the housing, and is then held in place by a plastic lens that has thrree latching prongs and pillars that mate with and alighn the PCB to press it onto the main heatsink.
The power supply uses a chip called an LNK606GG and it appears to be a standard 5.5W switching supply controller for either mains adaptors or in this case a current regulated supply to the LED. An oddity with the design was a wire that appeared to come directly from the windings of the transformer to the rectifier diode on the LED PCB, with two wires coming back from the LED for the common and smoothing of the rectified voltage.
As I say, a really attractive and nicely engineered lamp, but the tiny single point 5W emitter doesn't make me feel comfortable. I just prefer my LEDs to be kept as cool as possible.
Brilliant! Electrician of the highest caliber and now Private Eye! This is tremendous stuff Clive , I know I am working thru your back catalogue ( making you sound like Paul McCartney!) as I am late to the channel but more of this would be ace!
Thanks Clive
Bob
morrisons own brand look exactly same as them ,a rebrand i guess ,another chinese factory OEM output
The lens is called a collimator and LEDs that size can handle 5W (1.5A drive current X 3.2V =4.8W). For a LED binned at 85deg C, a heatsink that size can easily work for a 5W LED. I can hardly see the LED and honestly, it looks like a Cree XPG LED but, could be one of the Osram Square LEDs. Hahahahaha! Just saw this video is over a year old. 😛
Clive, on a different note… where do you live? If you live outside of USA. can you make a video of the town you are in… I think you might be in England but might be wrong..
LNKxxx DIL and SO package chips often have only 7 pins.
5W is close to the maximum that can be dissipated in a lamp this size, but I do have some Lighting Science Group LED lamps this size that are 6W. What would be a problem is the lack of thermal grease.
That heatsink is zamak alloy, not aluminum. The dark gray color and hardness are giveaways. Zamak is an alloy of zinc, aluminum, magnesium and copper that has comparable thermal conductivity to aluminum but doesn't eat casting dies the way aluminum does. Not needing a new set of dies every few thousand pieces helps cut costs.
The LNK606 is a dc-dc converter chip with built in mosfet and all the jazz… that takes rectified AC voltage and sends "pulses" through the transformer… it uses one winding for feedback and therefore there's no need for optocouplers or other parts to regulate the output voltage.
Basically, the main pcb is just a dc adapter like any phone charger. The chip can do maximum 5.5 watts.. up to that point they're not lying.
The part on the aluminum pcb may be a led driver, or some basic linear current limiter, to protect the led.
Did you measure the wattage in use? Curious how much Watt that single LED actually draws…
Clive, what would active cooling be on an LED lamp? A fan?
Also, what is your favourite bayonet/screw LED replacement for a standard incandescent light bulb? Thanks.