Wiring up LEDs

[andyelbac]

Hi, I am your average person ignorant of electrical knowledge and need some advice on wiring up led's for a model I am making. Basically, I need to connect a dozen 3mm LEDs (the tiny bulbs with two wire legs coming off the body). The entire length will about 1.5mt long and the LEDs will be attached about every 5 to 6 inches along the length of wires with one at the very end. To put this into more context, I am building a 53" long model of a U Boat which has a cutaway body on one side. The led harness will light up the various compartments. Is it a simple case of exposing the wires (positive and negative) along various sections of the wires, soldering the legs to the correct wires, insulating and then connecting the end of the wire to a 12v converter so I can plug into the mains or do I need to be adding resistors or capacitors to make it safe? Any advice would be welcome.

 

[littlespark]

I think i understand what youre trying to do, and i cant see any problem just having them all connected in parallel. However, the small LED's run on 1.5v i believe, so extra components would be required.

Would ex-christmas fairy lights do the same job? ie, buy something thats already made up.

 

[andyelbac]

I think i understand what youre trying to do, and i cant see any problem just having them all connected in parallel. However, the small LED's run on 1.5v i believe, so extra components would be required.

Would ex-christmas fairy lights do the same job? ie, buy something thats already made up.

I may have been talking out of my rear when I said 12v...irrespective, your idea about xmas lights might be the way to go. I have some around somewhere so will check them out. Thanks!

 

[DPG]

There are cheap led strings available on ebay and from discount shops etc. and this would be the easiest method. But nothing to stop you soldering some together yourself.

Connect each LED in series with a current limiting resistor, and then connect each of these assemblies in parallel across the positive and negative of a DC supply.

If you decide to go down this route then the value of each resistor will depend on the forward voltage of your LEDs and the supply voltage. Typically around 470 Ohms on a 9VDC supply.