Voltage Regulators: Breadboarding A Diy Usb Power Supply

Today we turn a 7805 Voltage Regulator and 4 AA batteries into a very simple Power Supply to charge anything that runs off USB. Breadboarding circuits are fun!

Sure, you can drop $20 on a perfectly good Energi To Go USB charger from Energizer.

But we were looking for an excuse to play with a basic +5V 7805 Voltage Regulator we saw for $1.59 at our local Radio Shack

So we grabbed our trusty breadboard, a 4 AA battery holder, some wire, and liberated a femail USB plug from a USB extender cable.

The nice thing about recycling USB cables for a power supply: just look for the black (-) and red (+) wires when you split the cable open.

While we're at it, we briefly talk about Linear Voltage Regultors (like the 7805) which act like a variable resistors, tend to heat up, and can only reduce voltage vs. Stepping Voltage Regulators, which turn off and on to regulate voltage, are super efficient, generate less heat, and can raise or lower voltage.

Did I say we? David's off building the studio this week, and Brendan's locked in a server closet.

Got a project idea or a question? Email us: systm@revision3.com