Cheap Power Supply for Projects (20v)
by AlexZhang in Workshop > Energy
1368 Views, 14 Favorites, 0 Comments
Cheap Power Supply for Projects (20v)
![DSCF1413.JPG](/proxy/?url=https://content.instructables.com/F70/92QT/I7AB2X7V/F7092QTI7AB2X7V.jpg&filename=DSCF1413.JPG)
This is a cheap and easy power supply that can be used for many things.
Materials
![DSCF1366.JPG](/proxy/?url=https://content.instructables.com/FAV/1B64/I7AB2VC3/FAV1B64I7AB2VC3.jpg&filename=DSCF1366.JPG)
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
![DSCF1369.JPG](/proxy/?url=https://content.instructables.com/FNT/EVR9/I7AB2VIL/FNTEVR9I7AB2VIL.jpg&filename=DSCF1369.JPG)
cut end off the cable that plugs into your laptop, make sure its not plugged in
Strip Wires
![DSCF1375.JPG](/proxy/?url=https://content.instructables.com/FXO/E7JB/I7AB2VVA/FXOE7JBI7AB2VVA.jpg&filename=DSCF1375.JPG)
![DSCF1377.JPG](/proxy/?url=https://content.instructables.com/FVI/8QIM/I7AB2VY3/FVI8QIMI7AB2VY3.jpg&filename=DSCF1377.JPG)
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.
![DSCF1381.JPG](/proxy/?url=https://content.instructables.com/FII/QK1V/I7AB2W0W/FIIQK1VI7AB2W0W.jpg&filename=DSCF1381.JPG)
![DSCF1388.JPG](/proxy/?url=https://content.instructables.com/FVG/U8OO/I7AB2W93/FVGU8OOI7AB2W93.jpg&filename=DSCF1388.JPG)
Add the nails onto the wires. Fold the wires together hold the wires and twist it together then wrap the wires with electrical tape.
![DSCF1393.JPG](/proxy/?url=https://content.instructables.com/FS6/BBZR/I7AB2WG9/FS6BBZRI7AB2WG9.jpg&filename=DSCF1393.JPG)
![DSCF1396.JPG](/proxy/?url=https://content.instructables.com/FQV/4BH8/I7AB2WJH/FQV4BH8I7AB2WJH.jpg&filename=DSCF1396.JPG)
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.
![DSCF1402.JPG](/proxy/?url=https://content.instructables.com/FXE/XR0A/I7AB2WQC/FXEXR0AI7AB2WQC.jpg&filename=DSCF1402.JPG)
Test for shorts if there is a short when you plug the power supply in the the Power supply will automatically turn off.
![DSCF1405.JPG](/proxy/?url=https://content.instructables.com/FQ9/4Q8T/I7AB2WZS/FQ94Q8TI7AB2WZS.jpg&filename=DSCF1405.JPG)
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)*
![DSCF1414.JPG](/proxy/?url=https://content.instructables.com/FHR/SAQS/I7AB2X8C/FHRSAQSI7AB2X8C.jpg&filename=DSCF1414.JPG)
![DSCF1412.JPG](/proxy/?url=https://content.instructables.com/FQN/4XWK/I7AB2X74/FQN4XWKI7AB2X74.jpg&filename=DSCF1412.JPG)
![DSCF1410.JPG](/proxy/?url=https://content.instructables.com/FMG/DZTO/I7AB2X4T/FMGDZTOI7AB2X4T.jpg&filename=DSCF1410.JPG)
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.