I’ve seen a few YouTube videos where people are replacing the Halogen bulb in a work light with a cheap COB LED. Thinking of attempting it myself for fun, also as the world’s most expensive electricity is sold here. The cheap COB LEDs selling on eBay could do the job but I was wondering if there are LEDs that for a few dollars more could be a lot better (eg. Lustreon)? I would aim to keep the budget to under $10 AUD (~$7 USD).
Here’s a study of the cheapest LED that runs on mains power going around…
These are the 100W they also make 50W. The disadvantage is that you will need a dc power supply for them, you cant jusg stick them over mains leads. The advatage is that there will be no flicker if you use decent power supply. For these I think you will need like 31V 3A power supply. 3A constant current supply would be best.
But I am not sure in what fixture you want to replace them. They really benefit from active cooling, it increases their longevity a lot. Something like this is usually sufficient, but you can go for better coolers:
The store in DrPhilip’s link has a section for Driverless LEDs. These are designed for direct connection to Mains power. Be aware than many are designed as Grow Lights (full- or augmented-spectrum) and look funny used in a worklight. I haven’t used these, perhaps someone can chime in with a suitable one.
Thats the think I dont likeabout them. I do understand the conveniece of it but I really do not like the flicker. I’ve had six different ones and none of the had smoothing capacitors. You could add it, but it would no longer be thin little cob.
But it might not be that bad, some people dont mind the 50-60hz strobe. Even many cheapo chinasium bulbs you buy in stores flicker at 50hz like mad. If its meant for short time emergency illumination it shouldnt be so bad.
But i wouldnt bother with anything of significant quality if you are just going to put it into thag housing. It will have a heatstroke without proper cooling so my recommendation is to stick with the cheapy chinasium ones.
I made the mistake of buying generic LED bulbs direct from Banggood/Gearbest, the flicker made them unusable for me.
If the inexpensive COB chips with internal drivers all flicker, then as it’s not a serious project, I might try one given the small cost. Big Clive (Youtuber mentioned above) if memory serves thinks the 30W variant might be driven at more sensible levels in line with the capability of the hardware.
If you do decide to go through these mods, make sure you ground every metal part that touches the cob, they have a habbit of becoming live on the bottom aluminium plate after fiberglass isolation oc the cob burns/arcs through. Got a decent kick from one once, they cannot be trusted to stay isolated on that bot plate.
That blue component most lilely is a metal oxide varistor. It will be directly across mains. It has a huge reisitance (megaohms) untill the voltage reaches a certain threshold. Once the voltage across it reaches certain value, its resistance drops to almost zero. It is used as overvoltage protection. Should the voltage on the mains increase above certian level (usually 385v) it starts conducting and filters those voltage spikes.
