cheapest current regulation for 12v powered lights

[James S]

Hi Folks,

I've been amassing LEd's and low voltage outdoor lighting lamps whenever they were on sale for like 2 years now in preparation for doing some LED powered outdoor lights without spending a lot of cash all at once.

I've been experimenting and just putting resisters in line with some of these things doesn't cut it. They are too thermally sensitive and will run away and prematurely go dim without proper current regulation.

I can build them really cheap current regulators with a voltage regulator in current mode, but that wastes a lot of power in a big resister too and I want to explore other options as well. I figure $5 or $6 to do a good job with a linear current regulator like that. And about the best I can find for doing it with some other kind of thing is a buck puck at around $15 a pop.

What other choices are there when it's not too important that it be tiny enough to fit in a flashlight? There is plenty of room in these lamps. Im going to be making a bunch of them so cost really is the primary concern.

 

[VidPro]

there is a whole series of cheap en-mass pumped out driver curcuits now available on the deal sites, like kai's and Kyles, you can get curcuits for $3 bucks apiece now. havent tried them for long enough, but they seem to have the same basic parts , and functions of the $15-20 ones we have been getting.

one of them was discussed http://www.candlepowerforums.com/vb/showthread.php?t=177947 here.
its rather hard to search here for the specified info you need, but mabey "12v & Driver" might get a few usable hits too, i saw one other new product for 12volts recentally.

Plus there is a few reasonably priced tri-cree things out in fully assembled packages for 12v or 120v that is finished, and has some reasonable heat syncing, and the price isnt terrible either, it would be nice if they would pump them out for $7 too .

them buck puck type things are amasing, my potted puck has been running non-stop now for some 4-5 years or something, in up to 80+ temps, and it acts the same as it did the day i bought it. i guess one should never underestimate american build quality , like georges curcuits (taskled.com) but not cheap like your asking .

 

[richdsu]

This may interest you :

http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1003,C1094,C1768,P13452

http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1003,C1094,C1768,P13452,D9377

Linear Technology LT3474 IC

:laughing:

http://www.taskled.com/ccxw.html

 

[James S]

I've ordered a bunch of boards from the kai domain website a week ago that I hope will arrive soon to play with. At just a few dollars for a relatively high powered regulation board that really opens things up to experimentation!

I will post again when they arrive and I have some time to play.