i, AFTER you get a decent pre-packaged kit (which is a good idea)..
there comes the usual downfall of BATTERIES.
For some of my Grandchildren, and for several elementary school
projects, I have used the Zero-Cost approach of the "Old PC Power
Supply". The kid can plug this in and never run out of batteries, for
stationary projects anyway. You get this:
5 volt DC power at several amps
12 volt DC power at several amps
-12 volt DC power (Only needed for some electronics experiments)
Runs from 120V 60 Hz OR 220V 50HZ (usually has a small switch to
Short-Circuit protection! WHEN you short out an output, the supply
turns off. Turn it off and back on again. So this is quite "Safe"
unless you put just-the-right small wire across the supply and have it
- You need to have some minimum LOAD on the +5 supply for the power
supply to work with no PC attached. A small 6 volt or 12 volt
automobile tail light bulb is good, and tells you "It's ON!". I have
also used a cool "Side Marker Light" that is has a small case and a
yellow lens, that was cheap at Wal-Mart. NOTE: 5V on the 12V bulb is
not too bright, but works). OR you can mount a 10 Ohm 10 Watt resistor
(Radio Shack) inside the power supply case. Of course, the FAN runs,
so the kid knows it's on when he/she goes to bed...
- You need to have some easy way for the kid(s) to attach things to the
"right" output connections. The best thing is to add some large
TERMINALS that you can arrange on a small board or on the chassis of
the supply, and LABEL THEM. Tape all those "extra" wires into a big
lump with electrical tape.
My favorite "Power Panel" is a piece of 1/8" wallboard with the shiny
white surface, used in cheap bathroom makeovers. Comes in big sheets,
but look for the cheap one with the corner broken! Easy to drill holes
for terminals, pilot lihhts etc. AND they are great for
marking: Permanent marker for power connection labels. And, It's a
White Board! Use those dry-erase markers for experiment labels. That
same wallboard makes great "experiment" or "Switch" panels. Use the
dry erase markers to draw the circuits, then hook them up with the
alligator-clip leads. You get the idea.
Here are a couple of pointers to examples:
..and more if you Google "use old pc power supply"
Suggestion: Get a package of those "Alligator clip leads" at Radio
Shack for the kids to connect up some small 12 volt bulbs, switches
Anyway, this way the "Batteries" never run out...
Regards, Terry King ...On The Mediterranean in Carthage