Lego USB Charger

Step 2 The electronics

The 3 parts needed for this step are:
- Short lego wire, cut the block piece off one end and strip about a centimeter of the wire off
- +5V Fixed-Voltage Regulator 7805
- Female usb port

Plug the lego wire onto the motor as shown in the photos, test out which wire is positive by connecting the stripped wires to a multimeter and cranking the motor. Wire the positive end to pin 1 (input) on the voltage regulator. Wire pin 3 (output) to pin 1 on the usb port (if staring into the socket while the contacts on the inside are facing down, pin one is the farthest to the left). Wire pin 4 on the usb socket, and pin 2 on the voltage regulator to the negative lego wire.

Comments

[Brickman]

do you know which side of the lego wire is positive and negative? O and Radioshack carries the 7805 voltage regulator, i got it pretty easily.

[dannystaple]

Since the motor can be turned either way, I think the polarity can change. The next question is would this still work if a tiny rectifier bridge was added - like this one - http://www.squidoo.com/freeforming-a-diode-h-bridge. It would drop a few volts mind...

[TarzanJr]

no lol

[wsx587]

do you need a voltage regulator

[Otaconmgs]

Where did you get the voltage regulator?

[merijnvw]

just search for voltage regulator 7805 and order it

[pballpro44]

can i use a different voltage regulator