Wall wort powered LED lamps?

Sleestak

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Dec 21, 2005
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Guys,

Got a handful of wall worts from father in law. He volunteers at Habitat for Humanity, and they throw away tons of them.

I want to know: can I devise a plug in LED lamp using a wall wort and 'circuitry' such as a protection or step up 'puck' etc?

Yes, I don't know much about this stuff, but I'm hot to try a project. Just got a handful of lux 1 batwing emitters for a song, figure I'll try some constructinatin'.

Example: the wall worts are as follows: 9v DC and 300mA x 2, 12v and 500mA, 12v and 400 mA, and 9v and 500 mA.

Is it possible to hook up two of the 1 watt batwing emitters to one of the 12v devices? What kind of wiring pattrn, serial or parallel? I'm not knowledgable in the volts/watts/mA stuff yet, so any suggestions would be helpful. What kind of electronics would make it feasible? I understand the basic concepts of heat sinking, etc, but could use some suggestions on that, too. Thinking about 'square' profile metal tubing from Lowes, and wiring the kit together with an 'on/off' switch. Maybe make a couple of them. Application is for a basement reloading bench. I will have powerful overhead flourescent lighting available to me, but I want to embellish it a little with more directed lighting. 'Work zones' if you will. I will be looking at more simple solutions for light dispersion, such as ping-pong balls, which make for a neat glow. I can look at dedicated reflectors later.

Again, I certainly don't know much about this stuff, but the only way I'm going learn is to get in there and try a project or ten. I'm not afraid to learn, but a few pointers will certainly help.
 

WildRice

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SW Michigan
WWEELLLLLLLL. I would start with 2x LUX I's and the 9v 300mA WW. What I would do to be safe is to either grab a few 1W resistors mabyee 4.7 and 10 ohm and use a multi-meter to be sure they dont get overdriven. OR grab some 1N4001 diodes, put 4-6 in series and use the meter as a tap to increace the current in steps.

(+)-->I--->I---/\/\/\/\/-----(-) LUX I-LUX I- resistor

(+)-->I--->I--------->I-->I-->I-->I-->I----(-) LUX-LUX-4001-4001-4001

If you need more assistance let me know

Jeff
 

Sleestak

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Dec 21, 2005
Messages
147
WildRice said:
WWEELLLLLLLL. I would start with 2x LUX I's and the 9v 300mA WW. What I would do to be safe is to either grab a few 1W resistors mabyee 4.7 and 10 ohm and use a multi-meter to be sure they dont get overdriven. OR grab some 1N4001 diodes, put 4-6 in series and use the meter as a tap to increace the current in steps.

(+)-->I--->I---/\/\/\/\/-----(-) LUX I-LUX I- resistor

(+)-->I--->I--------->I-->I-->I-->I-->I----(-) LUX-LUX-4001-4001-4001

If you need more assistance let me know

Jeff

Excellent! Thank you. Ummmm... Could I humbly request place for the resisters, a hobby supply place? Also could use some random wiring. I'm definitely a noob at this, but any time I put my mind to something I can generally figure it out with practice. Might beg some more data from you later, if that's okay. One of the reason this appeals to me is that it's not inclusive of expended batteries or the need to recharge batteries, and is dealing with generally low voltages, which keeps the whole thing safe. Just a fun project for the reloading bench. If it goes well, I might try an LED disco ball or something like that. :grin2:

Thanks!
 

WildRice

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Joined
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Messages
1,135
Location
SW Michigan
Rat shack should carry these values. Remember, at MOST you would need a 1W resistor (wire wound is best.) If each LED runs at 3.7V at 350mA (rated power) then 2 in series would draw 7.4v at 350mA. if the power supply was able to hold 9v at 350mA then 1.6v would be across the resistor. P(wattage)=I(current) x E(voltage) (P=IE) or 1.6(V) x .35 (Amps) = .56 (watts)

ALSO, a thing to remember. not all LUX slugs isolated from the + and - terminals. Just be sure to check. you can use a multimeter on diode check and check the base to - and base to +. If the bases have no connection to the -+ then all is OK. if there IS a voltage path to the base then one or both (if on the same heat sink) will need to be isolated from the heatsink.

Good luck.

Jeff
 

mpk

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Oct 12, 2005
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Sleestak said:
Got a handful of wall worts from father in law. He volunteers at Habitat for Humanity, and they throw away tons of them.
What is Habitat installing in those houses that they don't need the wall warts?
 

blgentry

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Please note, "wall wart" transformers have a reputation as "fire starters". I have never had a problem personally, but I also unplug all wall warts that are not in use and in some cases, I refuse to use them unless I am in the house when they are plugged in.

Seeing as how you will be using these power supplies outside of their original application, you should be extra cautious IMHO. If you are experimenting "live" the worst you'll have is a blown up transformer. If, on the other hand, you design a circuit that runs the transformer to it's limits and leave it on when you are gone, you may start a fire in the transformer, which may or may not spread. I would be VERY cautious of leaving a home designed circuit plugged into any kind of wall wart while I was not in the house.

Just a little something to think about.

Brian.
 

Sleestak

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Dec 21, 2005
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147
mpk said:
What is Habitat installing in those houses that they don't need the wall warts?

It's more at the 'input' side of things. FIL used to work with satellites and such, and he's a whiz at electronics.

He works at a Habitat outlet store, where folks can donate things for resale, a charity based system. He volunteers there to fix the electronics, and there's a lot of good stuff, but also a lot of stuff that's just not appealing to others or is too far gone to fix. Old camcorders, old cordless phones, things that have stopped working in some way or another and are not worth it to fix (part more than the value of the device, or nobody would buy it anyway). Jeez, he had an old camcorder on his workbench that was the old 'shoulder fired' type that used a full sized VHS tape. Thing was an enormous tank.

He salvages the parts off of stuff that doesn't work, because it isn't uncommon over the course of a year that several of the same types of things will come over his counter. Talking to him, it is amazing how many different brands of electronics use so many of the same parts. Some are exactly the same, or built by one company and marketed by another. One excellent example is the "LG" (IIRC) brand of electronics. Now marketed under their own labels, these exact products (or at least spirit and image close) are marketed by other companies with different facades. I have an LG dehumidifier that I bought for just over a hundred bucks, the exact same basic mechanicals marketed by another company for around 3-3.5 times the price.

Anyhow, of the things that seem to be nearly indestructable is the wall worts. He told me that only about one in a hundred or so ever go bad in his experience, and that they can last seemingly forever while still staying within spec. That kind of reliability is what got me interested in a wall wort powered LED setup. Get that puppy online, and you've got yourself a 'forever light' right there in your basement. I mean, something that just seems to refuse to go bad.

He said that they have to discard literally boxes and boxes of the things, because there is no market for them (nobody buys them at the Habitat store). I told him to save those boxes for me. Amazing range of volts and mA, and so this also got me to thinking about possibilities. Some seem custom made for LED clusters: the mA and the volts seem to work out exactly like the LED specs read, when used in multiples.

This should be a fun project.

 

Sleestak

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Joined
Dec 21, 2005
Messages
147
blgentry said:
Please note, "wall wart" transformers have a reputation as "fire starters". I have never had a problem personally, but I also unplug all wall warts that are not in use and in some cases, I refuse to use them unless I am in the house when they are plugged in.

Seeing as how you will be using these power supplies outside of their original application, you should be extra cautious IMHO. If you are experimenting "live" the worst you'll have is a blown up transformer. If, on the other hand, you design a circuit that runs the transformer to it's limits and leave it on when you are gone, you may start a fire in the transformer, which may or may not spread. I would be VERY cautious of leaving a home designed circuit plugged into any kind of wall wart while I was not in the house.

Just a little something to think about.

Brian.

Excellent advice, and well taken. I'm kind of a stickler for this sort of thing, too. I generally am loathe to leave lights on unless they are very safe or in a very safe position. I'm kind of an 'unplug things before you go on vacation' sort. Just to be safe. The only 'active' utilization for these lights would be when I was directly using the space. Otherwise, I'd have the wall wort out of the socket. Gotta keep the projects safe. :)
 

ken2400

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Joined
Oct 30, 2006
Messages
227
Use a multi meter to track power usage. LEDs can burn out faster if too much current is given to them.

Good luck.
 

orionlion82

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Joined
Dec 21, 2006
Messages
296
blgentry said:
Please note, "wall wart" transformers have a reputation as "fire starters". I have never had a problem personally, but I also unplug all wall warts that are not in use and in some cases, I refuse to use them unless I am in the house when they are plugged in.

Seeing as how you will be using these power supplies outside of their original application, you should be extra cautious IMHO. If you are experimenting "live" the worst you'll have is a blown up transformer. If, on the other hand, you design a circuit that runs the transformer to it's limits and leave it on when you are gone, you may start a fire in the transformer, which may or may not spread. I would be VERY cautious of leaving a home designed circuit plugged into any kind of wall wart while I was not in the house.

Just a little something to think about.

Brian.


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A "Wall Wort" is a Transformer.
It is a coil of wire, in its simplest terms.
A primary coil, and a secondary coil that gets power through induction.
the turns of wire equate to voltage change.

If you cant bear them, shut off your computer. as you have several of them in it. disconnect your house with the main switch immediately so you do not set fire to the pole transformer. NEVER enter ANY commercal building, as they have them - on the order of multiple ones that weigh several thousand pounds, and usually fed with wires as large as the diameter of a quarter at several hundred volts. you will surely have some sort of attack...

there is absolutely NOTHING unsafe about transformers, unless they are overloaded or contain a design flaw - as long as they are saftey rated - "listed" is the term the NEC uses.

wall warts will draw a small amount of power if left plugged in with no load, however it is NOT something the vast majority of the world should be concerned with (or is). yes - they make heat, but these units are not 100% efficient and some can get quite hot within spec, and life goes on.

STOP spreading this nonsense around. people are starting to believe your misinformation.

there are very, very few "wall wart" fires each year. most are due to defective units, or an overload/improper overcurrent protection.
they arent out to get you - i promise.
it is silliness to think otherwise.

a listed transformer used correctly - barring defect- is simply fine to use as needed.

you can allso actually OVERLOAD any transformer some 25% temporarily, as long as provisions are made to keep it cool.

many actively cooled computer power supplies (the cheaper ones) use this to their advantage - to my knowladge- to meet nameplate max ratings with smaller cheaper transformers and screaming fans.

chill.
its okay to use wall worts. i wouldnt put my name on a post if it werent.
 
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