This is a cheap and easy power supply that can be used for many things.
Step 1: Materials
1. laptop power supply (old)
2. hot glue
3. electrical tape
4. wire cutters(optional)
5. 3 nails
8. small cardboard box
no soldering required
cut end off the cable that plugs into your laptop, make sure its not plugged in
Step 3: Strip Wires
you will find 3 layers of isolation and 3 wires, strip the isolation off of the wires. The smallest wire in the middle is usually the ground.
Add the nails onto the wires. Fold the wires together hold the wires and twist it together then wrap the wires with electrical tape.
Push the nails into the box and make sure the ground nail is in the center. Then glue or tape the nails onto the box.
Test for shorts if there is a short when you plug the power supply in the the Power supply will automatically turn off.
If all is working then wrap the excess wire around the power supply around it and then glue the power supply into the box. *(not the cable that connects to the wall)*
close off the box and find out the polarity of the power supply then label it. your now done. a laptop power supply will automatically shut off if there is a short so your safe if it shorts. you can connect alligator clips and paperclips easily to the nails. this is really cheap, if you already have a laptop power supply then it would be even cheaper. total cost is under $15 and that includes a 95w psu. any laptop psu should work.