Hello,

I've read through some threads here and I'm hoping to summarize what I want to do and see if I understand it correctly. I have built several little electronics kits (wheel of fortune, blinky, sound generator, etc.) for this first question let's assume they all run on there own 9 Volt battery.

Yes or No (or it ain't that simple)
Can I use a single 9 Volt wall wart to power all of these kits as long as I don't exceed the total combined amperage of the devices?

Question 2, let's assume for this one that 3 of the kits use a 9 volt battery and 3 of them use 3 volts.

I'm assuming that I can wire up the 3 9 volt ones directly. How do I step down the 9 volt Wall Wart to power the 3 volt kits?

In my head I'm thinking I take a 9 volt lead from the wall wart and hook it to some type of step down circuit and then run the 3 volt leads off of that circuit. Again I'm thinking as many 3 volts as I want as long as all kits (3 & 9 volts) don't exceed total amps of the Wall Wart.

Really appreciate your help on this. My ultimate goal is to build a panel of 8 - 10 of these kits powered off a Wall Wart so I can power any one or all of them without having to deal with battery replacements.

Thanks a bunch,

Dennis

 

Can I use a single 9 Volt wall wart to power all of these kits as long as I don't exceed the total combined amperage of the devices?

Yes. I made a supply bus with multiple battery snaps along a length of split loom tubing for a display once. Many of the kits that use a 9V battery can be safely run from 12V as well.

Question 2, let's assume for this one that 3 of the kits use a 9 volt battery and 3 of them use 3 volts.

I'm assuming that I can wire up the 3 9 volt ones directly. How do I step down the 9 volt Wall Wart to power the 3 volt kits?

The simplest way is to set up an LM317 adjustable voltage regulator to provide the 3V. If you're not drawing too much current, you won't even need a heat sink.

 

Can I use a single 9 Volt wall wart to power all of these kits as long as I don't exceed the total combined amperage of the devices?

Just so its clear.. You buy a 9V wall wart that has a current rating "greater" than the total of all the devices.. Loads (your devices) only "pull" what they require. I usually go 125% or more. So if your devices require 3 Amps get a wallwart with a rating of 4 Amps or more.