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Help with LED-transformer calculations?

899 Views 3 Replies 3 Participants Last post by  SpiderWitch
There was a previous thread (well, there were several) which discussed modifying a flickering LED tea light to run off a transformer, and it was great- but DH and I hit a stumbling block in trying to determine what exactly we needed to run multiple LEDs? We've got 15 of the standard-issue LED tea light candles which we'd like to run off a transformer- and that's where it fell apart. What size- 4.5 or 9v? Do we wire in series, or parallel? How many ohms? volts? amps? Roentgens? Cochranes? And why is the Chameleon Circuit stuck in 1968 again?

Help gratefully welcome, mockery bitterly accepted :D
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No mocking here! it's never easy figuring this stuff out. Here's some suggestions:
Always wire in parallel, so all your lights see the same voltage. I used a 5 volts phone charger adapter and I can run lots of them with that.
I made a video a little while ago which might explain things. It's a little lengthy, but I try to explain EVERYTHING! :)
No resistors needed, as in this case they will just make the lights dimmer.
Hope this helps!
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if your going to do the 5vdc trick look into the USB hubs.

Get a USB hub with the AC adapter (usually about $4-5 on amazon) and then each port has a 5VDC power source. The hubs can come anywhere from 4 to 10 outputs. Each 5vdc source should have about .5 A to 0.9 amps max. that is enough to run about 15 leds each.

This is where i get my L.E.D.s the nice thing about them is they give all the pertinent information (voltage, and amperage). https://www.superbrightleds.com/moreinfo/component-leds/5mm-red-high-flux-led-90-degree-viewing-angle-5500-mcd/356/1303/#/tab/Specifications

they have their own calculator but i prefer this one http://www.ledcalc.net/

hope this helps. i used all this info to make led spot lights but it will apply to your LED candles
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Thanks Dave- so let me see if I understand...
If I use a phone charger (5v), I need two of the diodes. These are hooked up pos-to-neg from the power supply to the diode, leaving a positive diode end free to connect to the tea lights (so the diodes essentially form an extension of the positive lead). The positive diode lead is connected to the positive lead of the tea light, and the negative end of the power supply is connected to the negative lead of the tea light?

If I'm right so far, then what's the next step to connect multiple lights? Does each light connect to another light, or do they all connect back to the same two leads of the power supply? A chain vs an octopus?
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