Thread: electricians chime in, some wall wart questions.

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so in 2009 (this past halloween) i went with some LED lights spotlights and battery operated tea lights. the output from the lights were fantastic but the only drawback was turning all of the candles on and off every night.

SO what i want to do is wire the tea lights to a wall wart like i do for my LED spotlights. NOW my question is this. the tea lights i have run on a 3 volt cr 2032 battery, for a wall wart i need to dig around for an ac 3v correct? now how many of the tea lights will i be able to connect to this power supply? i know the mA has to do with it but all of the 3v supplies i have found didnt show any type of mA.

i tried to hook up a spotlight to the power supply i have now. it worked but it did not flicker and just stayed lit and really bright. after putting the battery back in and trying the tea light, it just stays lip, no more flickering so obviously the amount of juice i put to it with the 12 vdc, 2000 mA really played an effect on it.

any info would be great, thanks.

How many tea lights are you planning on wiring up? I can't imagine they pull many mAs. You'll need to wire them in parallel to get proper voltage to each. I doubt the flicker circuitry would allow for serial wiring with higher voltage.

Safest thing to do would be to measure the current draw with a multimeter, then do the math.

That said, something like this (while 3.3v) would provide more than enough current.

-dgm

Originally Posted by dadgonemad

How many tea lights are you planning on wiring up? I can't imagine they pull many mAs. You'll need to wire them in parallel to get proper voltage to each. I doubt the flicker circuitry would allow for serial wiring with higher voltage.

Safest thing to do would be to measure the current draw with a multimeter, then do the math.

That said, something like this (while 3.3v) would provide more than enough current.

-dgm

I second this. LED's usually draw about 20mA so you can hook up quite a few.

Yes you can wire to a wall wart. Yes a 3Volt wart is needed for the simplest solution.

Tea lights areled and take little power, hence the 2032 battery. Therefore anything 300-500ma should work for a whole bunch of lights.

The Wart;

Always remember that analog based warts (those using a transformer) are voltage rated at their current draw, which means a wart rated at 3V @ 500ma will measure 3V with a 500ma current draw attached. which means with no current they may put out 5-5volts. This may be enough to burn out the tea candles if you get to big a transformer. I would suspect a tea light may draw 5ma so if you had 10 light that would equal 50ma current draw. A 500ms wart would be too much.

The Wart part 2;

If you can find a 3V switching power supply (transformerless) (usually high amperage) then it will always put out 3V no matter the current hooked up to it. That would be ideal but may be hard to find in a wart.

The wart part 3;

So you cant find part 2, or its really expensive. Your alternative is to get a 5V cheapo art and built a very simple IC 3V regulator circuit (a couple bucks in parts) . Or find one that some has built. This would provide a constant regulated 3V from the cheapo wart.


But here's your answer;

Power Supply Adapter 110-240V Converter DC 3V - eBay (item 200402855214 end time Dec-06-09 02:59:45 PST)


I am pretty sure this is wart part 2 as its very small for the current rating of 1 amp (indicative of a transformerless design). Best is to measure the voltage without load.

ib

Originally Posted by dadgonemad

That said, something like this (while 3.3v) would provide more than enough current.

-dgm

Definitely that ones a switching supply, and at a good price for 4.5 amps!

IB

thanks.
like i said i hooked it up to my 12vdc supply i have running my LED spotlights and it was just 2 much for the LED. guessing the low voltage makes the LED flicker. because now since i put the 12vdc to the candle, replacing the batteries and powering it up it quit flickering, it just stays lit.

i ended up running across some 3vdc power supplies on ebay that have 500mA. as for how many i plan on hooking up... depends on how many i get finished making. probably around 40-60?


i know with my mini spotlights the 12vdc 2000mA supply i have will power 80 lights.


i used to run the flickering flame bulbs, but they get $.
is it safer running the LED spotlights over the flickering 3w bulbs?

thanks JEEPIN! and dadgonemad im gonna pick that up for the price it wont hurt to try for that price!

ill let you know how it works out, thanks for the info!

ok now for my next question....

i would like to build a simple plug and play unit for my flickering candle lights. what i would like to do is this...

i would like to put a DC jack on one end of a circuit board then from there run 3.5mm audio jacks from there, then on the backside of all my candle units i coould put 3.5mm audio jacks. that way i could just plug and play all my candle sets with a 3.5mm X 3.5mm audio cable. is this possible? is this more hassle then its worth?

in a nutshell...

on the backside of my candle fixtures i would have something like this:


then on my "power board" i would have the DC jack input along with a bunch of these stereo jacks:


then i could run various lengths of:


to the candle sets. this is probably more trouble/hassle then its worth & will get expensive buying all the cables, but im just curious, will the stereo plug cables carry the power even? i dont see why not, as long as the + and - are hooked up right.

otherwise im just going to hook up the power supply to some nylon terminal blocks and run about 8' - 10' leads from the candle sets i can run to the blocks, that way i can position a terminal block in the center of the room in the ceiling and run everything to that.

basically im just trying to find a nice plug and play way of doing this BUT the price would probably be absurd. using the nylon terminal block will work it just sucks so hard pissing with tiny screwdrivers all the time with your head up in the slats of the ceiling.



i want to convert EVERYTHING to LED because its just a safer alternative. bulbs dont get hot and the wattage is lower after running form the power supply.
the only thing i miss about having the old flickering bulbs and c7 bulb spotlights is just plugging the cord into a surge protector and calling it a day. thats what i want to try to recreate but in LED form.

First point, your post said AC 3v you mean DC 3v? Second point, audio cable for the runs your talking about is going to cost you bucks (you did say 40 tea lights?). I'm thinking 5 dollar cable solution for a 50 cent light? How about using bulk wire (doorbell wire or cheep speaker) And I don't know much about wire size requirement but I have used twisted pair network cable for led in the past when I had a single led pair a distance away without issue. Four pairs in a cable got to the general are and split them from there. My last idea is think about how they do landscape lights, run a 3v wire around the yard and vampire tap into it with shorter wires fastened to the tea lights. My guess is tha someone here will tell me why the network cable or vampire tap solution is a bad idea.

Ok sorry, my last idea is never my last, what about RJ11 phone jacks, Im sure someone here knows what type of power is sent down the line whe the phone rings, cheap (really cheap) and keyed so you can't miss connect them

Here another question to pose:

I bought a broken portable dvd player from ebay, without the wall wart. The input is 9v @ 2.3a. There's a electronic store in the area that sells all kinds of wall warts, but the only ones I can find are 9v @2.1a and 9v@2.5a. Which should I choose?

Victor