Tag Archives: Video

Make a coin battery – great electronics project for kids!

What better way to illustrate how to build a basic electronic connection than to use coins to build a battery?

Here’s what you need:



quarters or dimes
aluminum foil
blotter paper (see below)
cider vinegar
wire (short length of both black and red wire – ~16 gauge)
1 LED (any through hole LED)
pen or marker
voltmeter (optional)


Trace the coins on the aluminum foil and blotter paper. Cut out 10 of each so that you have 10 circles of aluminum foil and 10 circles of blotter paper.

(Blotter paper can be found in the art store or the art section of your local craft store. You can also find blotter paper in the cosmetics department. If you can’t locate blotter paper, then you can also try using thick paper towels.)

Mix a small amount (1/4 cup) of vinegar with some salt. Stir the salt until dissolved. If the salt can not dissolve, then you’ve added too much. Add some additional vinegar and stir. Soak the circles of blotter paper in the vinegar and salt mixture.

Stack the foil, blotter paper and coins as shown in the video. It is important that the foil not touch the other layers. Let the ‘battery’ stand for about 15 minutes to develop a charge.

Connect each lead of the LED to a short piece of wire; the black wire connects to the negative lead and the red wire is attached to the positive lead on the LED. Place the exposed end of negative wire on the bottom of the ‘battery’ touching the foil, and the end of the positive wire to the quarter on top of the stack.

Optional: Use the voltmeter to measure how many volts are generated by the battery. A battery with 6 or more cells should be able to light up a standard LED with no problem!

Custom Console Stereo

For those of you wanting to hear just how good a custom built vacuum tube amp or console stereo will sound, here’s a video from Steve at Custom Tube Art which shows the workmanship of his projects and the quality of the sound.

Steve had this to say about his latest project:

Here is a 1960’s style custom console stereo I built displaying the vacuum tube amplifier right next to the Garrard type A turntable. The 807 tube amplifier has a conservative output of 30 watts per channel and uses 6SN7 and 12AU7 pre amp tubes. The speakers are a pair of Jensen 15″ drivers and a pair of DeForest 3″ tweeters in each cabinet. The entire project took two months to build.

You can see more of Steve’s custom work on his Vacuum Tube Amp web site.