Testing Super Cheap LED light

[SLUG36]

after not being satisfied with the light output of the 3/4" Clear LED side marker lights that cost $18 for a set of 6. I decided to do some budget testing of some cheap LED flash lights. I had a couple laying in the junk drawers in the kitchen, being long forgotten. I decided to do some experimental destructive testing. it turns out that a led flash light that uses 4.5v DC to operate will not last long with 12v DC surging through the little diodes. Recalling my wasted Robotics Schooling from 14 years ago, where remembering the professor telling us that a single cell battery can only produce 1.5v DC max. I came up with the 4.5v dc voltage required by multiplying the 1.5v DC by the number of batteries, in this case being 3 (1.5x3=4.5). Then dividing 12v dc by the voltage required to operate a single LED flashlight, being on the safe and lazy side, i decided to use 3~ 4.5v LED flash lights to drop the 12vdc. ( 3x4.5v=13.5v). this should work without frying the LED's (in theory). Being connected in "Series" being the Positive connection of one light module being hooked up to the positive output of the power source and the negative connection of the light module being connected to the positive connection of the next light module, and so on. with the negative connection of the last module being connected to the negative of the power source. DC series circuits divide voltage and share amperage.

While at WalMart yesterday, I scored 3 Cheapo LED flashlights @ $1 each.

http://www.walmart.com/ip/Generic-5026-Ozark-Trail-9-LED-Mini-Flashlight/34350005


These LED flashlights have the heads Sonic welded to the body's. So after chucking into my Metal Lathe, and using a Japanese Back Saw to separate the head from the body, I was able to remove the light module from the Flashlight head. Figuring out the power input's for the module, I wired them up in "Series".

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Here is a pic of the 3 module light assembly light with a 12v DC power supply from a Tower style Computer in a Pitch Dark garage.



After my Retina recover from the extreme light output, I was able to make this post.

[GuitarPhotog]

Harbor Freight was giving away those flashlights with every purchase a while ago.

You can't beat "free."

<Chas>

[Shadow Catcher]

I tested one of the ten G4 LED arrays that I got for $10 including postage to destruction and they would be a good bit less trouble to hook up.

[SLUG36]

Harbor Freight was giving away those flashlights with every purchase a while ago.

You can't beat "free."

<Chas>

you sure cant, but I fried the free ones I had laying around.

[SLUG36]

Harbor Freight was giving away those flashlights with every purchase a while ago.

You can't beat "free."

<Chas>

you sure cant, but I fried the free ones I had laying around.

I tested one of the ten G4 LED arrays that I got for $10 including postage to destruction and they would be a good bit less trouble to hook up.

probably, but having the CFO breathing down my neck. and having received a stern talking to about stuff arriving in the mail. I decided I could sneak these into the house when she wasn't looking.

[SLUG36]

I finally made a housing for this setup. spun up a piece of scrap oak 4x4 from a pallet on the lathe. the center line for the 15/16" holes are 120 degrees apart and 1/2" from the outer edge.

[eggsalad]

What you got right there is a $3 light in a $30 housing. I wish I had the kind of woodworking skills and machinery that you have.

[SLUG36]

thanks for the compliment. with the exception of the LED lights. I had everything else laying around the shop.

[SLUG36]

I finally finished doing something with the LED light setup. I decided to make a reading light for my wife. the arm is from my drill press that the LED light burned out on 5 minutes after setting up the Drill Press. it has been in my way for over 4 years.

[Lgboro]

I believe you will still burn out you leds as whatever you charge with will put up to 14.2 volts and will read over 13 with a full charge on your battery . Don't ask me how I found out....

[SLUG36]

I am using a computer power supply for my LED power source. I am thinking of using the 5v output of the power source for the LED lights.

[GuitarPhotog]

I am using a computer power supply for my LED power source. I am thinking of using the 5v output of the power source for the LED lights.

5V won't light most LEDs. Use the 12 VDC out.

<Chas>

[SLUG36]

I am using a computer power supply for my LED power source. I am thinking of using the 5v output of the power source for the LED lights.

5V won't light most LEDs. Use the 12 VDC out.

<Chas>

right now I have them temporarily hooked up to a old Sears 6v/12v battery charger. they work on the 6v output, just not as bright.

i figured that each LED module will drop 4.5v, (each cheapo flash light used 3~1.5v AAA batteries) and there are 3~ LED modules, run in series, they should be able to drop 13.5v. while using the same amperage. if i remember correctly from my DC circuits class from 15 years ago...

so, hopefully, the light will last for a while. and if not. I only have $12 in it.

[eggsalad]

I am using a computer power supply for my LED power source. I am thinking of using the 5v output of the power source for the LED lights.

5V won't light most LEDs. Use the 12 VDC out.

<Chas>

I'll beg to disagree with you. All (I.e. 100%) of LEDs function at either 3.3v or 5v DC.

That being said, there are a lot of LED fixtures designed to run on 12VDC. They do that by stepping down the voltage (via a resistor or more complicated system) from 12VDC to the 3.3 or 5VDC that the LEDs actually use. That's because cars, trucks, campers, and boats have 12VDC systems. Also because 120VAC -> 12VDC power supplies are cheap and common for residential or commercial use.

Heck, I've just ordered some LED work lights for the shop that will run on anything from 100VAC-277VAC!

BUT... discrete component LEDs ALL run on either 3.3VDC or 5VDC.