A 6-V battery powers a circuit with parallel branches on a board. Several wires and light bulbs plug into the board to make various series and parallel circuits. The brightness of the bulbs changes ...

Slide 1 of 2, A complete circuit with a cell and a bulb. The bulb is radiating light., A complete circuit Wires connect the battery and bulb in a complete loop.

Your gadgets run on direct current, but the electricity in your home is alternating current. What’s up with that?

The process begins with gathering the necessary components: a 9V battery, an LED light strip or bulb, an on/off switch, wire, electrical tape or a soldering kit, and Velcro or adhesive for mounting.

Sometimes you need to attach a ground wire from the housing to the dash frame to perform a good test of the bulbs. The '69-'73 Mustang dash lights ground through the printed circuit board.