Starburst lamp revisit 11 years later
Added 2024-09-23 15:50:22 +0000 UTCIt's been a very long time since I first looked at one of these bulbs. They have a stack of PCBs inside with LEDs splayed out from them to give a lot of sharp points of light in a globe. Very sparkly looking.
This is a newer version with different circuitry that is optimised for a wider voltage range and different sized bulbs that may use more or less of the cluster PCBs.
Comments
Well I tested with a DC supply and 15 of them work just fine. I set up my bench Variac and a full wave rectifier from 4 1N4007 for a DC supply with lots of ripple. And yes it made many of them reset back to red.
Charles Bruckner
2024-09-25 03:44:44 +0000 UTCWith a smoothed DC supply, a series string of slow colour changing LEDs will usually hold their colour. I think the main issue will be if the supply current is limited and you have more than one series string in parallel, since the string that currently has the lowest combined forward voltage will pull the voltage down and hog all the current.
Big Clive
2024-09-24 16:31:19 +0000 UTCJust going to set up 15 of them in a bread board. and power them up on the bench supply.
Charles Bruckner
2024-09-24 14:16:54 +0000 UTCI wonder how manufacturers manage to put 400V onto a tiny IC without the magic blue smoke emitting? It sounds too good to be true, but then these chips are pretty ubiquitous, so they must have figured out a way.
Mark Warburton
2024-09-24 14:12:00 +0000 UTCI suspect that they'll keep resetting to all red. But please take one for the team.
Alice Chapman
2024-09-24 13:39:44 +0000 UTCI have some on hand, and if I remember correctly each board is 15 in series for a string voltage of 40v. I will do a quick experiment to see how the LED's I have will behave.
Charles Bruckner
2024-09-24 11:22:59 +0000 UTCIt would be quite interesting. But all the LEDs would need to be in series as the changing colours results in a change in voltage across the LED string meaning it's less suitable for wiring them in parallel.
Big Clive
2024-09-24 03:07:01 +0000 UTCI would love to see one with slow color changing LED's
Charles Bruckner
2024-09-23 23:12:31 +0000 UTCQuite a nice decorative lamp. That would look good in most places.
Mike Hughes
2024-09-23 16:44:59 +0000 UTC
