# Very (very) basic power question

Thread Starter

#### turtlesplatter

Joined Oct 26, 2016
7
Hello all. First time poster, long time lurker of this site.

Based on what I have seen from this site, there are a LOT of knowledgeable folks on this forum so my question may seem extremely sophomoric. Although I am an avid DIYer, My electronics background is novice at best (i.e. I can design a basic circuit and I do know the difference between a resistor and a relay )

I am currently in the process of lighting up my Lego (yes, Lego) town. Will be obtaining prefab LED lighting kits from various sources (i.e. lightmybricks.com and lifelites.com) Each kit consist of an average of 25+ LED lights and each kit is powered by a battery pack that uses 3 AA batteries. My question is, I will be lighting up about 15 - 20 structures which would entail me buying 15 - 20 kits which means 15 - 20 separate battery packs which equals to 15 - 20 separate on/off switches. I would like to consolidate all the power into a single battery pack with an on/off toggle switch. What would be the best way to accomplish this? I am assuming a battery pack with 45 - 60 AA batteries is neither the best (nor practical) design. In other words, what type of battery pack(s) could I build that would obtain the needed voltage/amperage/wattage to power the entire town adequately?

***BONUS QUESTION*** Can I/could I/ accomplish all of this using a power adapter?

Thanks in advance,

m.

#### wayneh

Joined Sep 9, 2010
17,160
This can be accomplished with a single power adaptor.

You need to know two things, the voltage and current requirements of each string. The 3 AA batteries are connected in either series or parallel. It's most likely series but you need to confirm this. Look for any information you can find about the string specifications; current, wattage, anything.

The power supply you need must have the same voltage as a single string (likely 4.5V) and a current rating that exceeds the sum of all your strings, for instance a 2A rated supply if you have 20 strings that require 80mA each (sum 1.6A).

It's very likely you could use a standard 5V supply you might already have on hand for this. Just come back with whatever details you can find and we'll see.

#12
Thread Starter

#### turtlesplatter

Joined Oct 26, 2016
7
So, I reached out to the seller to obtain the specs on the LEDs and explained my dilemma. As luck would have it, they have informed me that they will be offering a USB PSU option and will be in stock next week. Awesome!

Thanks for the reply back.

m.

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