BlackBox AddOn #1 - Alternate Power Input





Introduction: BlackBox AddOn #1 - Alternate Power Input

READ THIS FIRST: This is an add-on to the BlackBox project which can be seen here.

In this Instructable I'll show you how to add an alternate power input to your BlackBox, so your batteries don't go empty as quick.
With this add-on, you can take a wall adapter belonging to a battery charger or a cell-phone charger and use it to power your BlackBox. The wall-adapter must have a DC jack like the one in picture #2 .

Step 1: Only a Few Parts Needed:

For this add-on you'll need:
  • a DPDT (double poll double throw) toggle switch
  • a 2.1mm or 2.5mm female DC jack (depending on what size the male DC jack your wall adapter has)
  • female and male header pins (recommended)
  • wire

Step 2: Add the DC Jack

First, drill the hole into your box and add the DC jack.
I added female header connections to the DC jack.
I didn't do my insulation nicely... I bet you can do it better.

Step 3: Adding the Switch

Now it's time to add the DPDT toggle switch, so you can switch between DC-jack-power and battery power.

Step 4: Rewiring

Now we must rewire the switches. Here's how:
  1. Look at your switches, you should see something like in pictures 1&2 (pic #2 is a simplification of the schematic)
  2. Now desolder and solder your wires to the new switch so you get something that resembles pictures 3&4 (pic #4 will be easier to understand).

Step 5: Reconnect Everything

Last Step: Reconnect your header pins.

Step 6: Finished!

Now you can listen to music on your BlackBox without depleting the batteries!
Don't forget to only plug in voltages that your amp can handle (The voltage output of your wall adapter can normally be found on the back of it).

Please rate, comment and have fun!



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    Most power jacks are designed to only run one form of power. Meaning if you have your circuits connected properly you can run off battery and when you plug it in it will run of the external power source. However if you want to have the speakers constantly plugged in and sometimes run off batter for whatever reason the way you did it is the way to go.

    Nice instructable!
    Very good Idea. being able to choose between batteries and wall power is always a really good feature for any electrical project.

    I'd like to add that it would be beneficial to measure the DC voltage coming out of the wall wart other than taking the manufacturer's word for it. I have had some wall warts that say 9V and really output 12V. often, the voltage ratings are at least a volt or two off (in my experience). Most of mine come from thrift stores. I don't know if having been used before makes a difference in what voltage it will output, but it would be better to measure the output just in case.

    Thanks for the compliments!
    Thanks for the tip too, I just tested my wall wart I was using and it indeed did only output 11V instead of 12V.

    Also, I would like to commend you on your photos! Taking pictures of you projects on graphing paper looks really neat and it suits electronics projects perfectly.