Cheap Power Supply for Projects (20v)




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

6. voltmeter

7. scissors

8. small cardboard box

no soldering required

Step 2:

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.

Step 4:

Add the nails onto the wires. Fold the wires together hold the wires and twist it together then wrap the wires with electrical tape.

Step 5:

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.

Step 6:

Test for shorts if there is a short when you plug the power supply in the the Power supply will automatically turn off.

Step 7:

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)*

Step 8:

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.



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    4 Discussions


    Reply 3 years ago on Introduction

    the power supply will automatically shut down if there is a short. it shouldnt be very dangerous


    3 years ago on Introduction

    I love re-using all sorts of old power adaptors. Anytime anyone is throwing one away, I always snag it. You never know when they will come in handy!

    1 reply

    Reply 3 years ago

    yeah they come in quite handy a USB charger can be used for a low voltage and current application like electroplating