Joule Thief

[jeanna]

bill or anyone

ive seen a few of you using the led christmas lights and lighting them from your JT and flash circuits, do you know what the arrangement of the leds are? are they in series or parallel? and did they need a special circuit or transformer for normal (pre JT) use?

im looking at making some custom under cabinet lighting i will post pics when i get it done and note my setup.

thanks!

Hi Artic Knight,
These led christmas lights are arranged in series. Normally they are sold as 35 or 70 leds in a string. There is also a hefty resistor or 2 because of the high led-killing surges common to the grid power.

This resistor might be embedded inside the plastic at the base of each end led. You will see there are multiple strings of 35 leds going one or the other direction.
Remove the end bulbs of each 35 led segment. (this bulb will have a third wire... just cut off the whole led and all 3 wires. It will work fine with 33 leds.

[So, you should end up with a string of 33 leds on 1 wire.]

Generally what I suggest and I have done is to take a useful number of leds off the string and make the connection yourself. There will be plenty of green matching wire ( ) to make your loop the right color if you need it.
This is easily done. The hardest part is untwisting all the wire and should take about 10 minutes.

AND, it looks good too.

jeanna

[Pirate88179]

Artic Knight:

I agree with Jeanna with one exception...the light strings I use all have 100 leds on them and no transformer or resistors as far as I can tell.  Maybe, as Jeanna has said, there might be a resistor buried in the plastic plug end but, the only thing I see is each string of 100 is fused and that is buried in the male plug end.  I am pretty sure my lights are in series also but, hard to tell for sure as they are the Icicle lights and have like 20 leds and then a branch of maybe 15 that hang out from the main string every few feet or so.

Bill

[resonanceman]

Artic Knight:

I agree with Jeanna with one exception...the light strings I use all have 100 leds on them and no transformer or resistors as far as I can tell.  Maybe, as Jeanna has said, there might be a resistor buried in the plastic plug end but, the only thing I see is each string of 100 is fused and that is buried in the male plug end.  I am pretty sure my lights are in series also but, hard to tell for sure as they are the Icicle lights and have like 20 leds and then a branch of maybe 15 that hang out from the main string every few feet or so.

Bill

I do more like Bill does
I have a few strings of 100 LED christmas lights.....I just clip alligator clips to the prongs of the plug


gary

[resonanceman]

I just got back from Walmart........it looks like lights of america  has been busy.
They had several lights there that are not yet  on the lights of america website.     
They had several  types of  the smaller bulbs with a  central pillar about half  inch thick and maybe an inch and 1/4 tall.
The  pillar has 6 surface mount LEDs on each edge.and  3 on the top.
The one I bought  was rated  at 2W   100 lumens.

They also had  a new higher power  floodlight .   it  was rated at 9 W
It  had 7  1/4 inch LEDs in it...... the price was $14 something........about the same as my 90 LED arrays cosr......
Now I kind of wish I had  got one of the new floodlights
I am sure a candy cane coil I have been playing  with would light it.
This coil is  big........ it has about 70 5 for $1 toroids ....... I connected  several smaller candy cane coils together.
I am not  sure how much voltage it has......
my meter only  goes up to 600V  ............
it lights a 25W CFL  to near full brightness ( using 12V ) It also easily lights up 3 strings of 100 LED christmas tree lights.

gary

[Artic_Knight]

thanks  bill and jenna,

now to plan a design. i either want to get a low profile metal U bracket and place each led in it myself (thats a lotta drilling!) or maybe i will get some puck lights. either way i dont want to rewire the kitchen and i dont want a power cable running from one set of cabinets to the other so why not apply a good efficient joule?

i have some 2400mah rechargeables around and im sure AA capacities have grown beyond that by now. my calculations for a 2400mah using your most efficient recent circuit gives a run time of about 60-70 hours assuming the batteries are calculated right and theres no special free energy thing going on

chances are i may go with the puck lights just because they seem hassle free i think. but the led string lights could be really neat for porch lighting.... choices choices.

so what are you guys working on these days? have a few crazy ideas for pushing the joule even more efficient or just trying to light more lights?