The interesting portion of the Wien bridge is the gain portion of the circuit. It’s just a simple resistor divider, with a light bulb thrown in on one of its legs.

It's a simple string of miniature light bulbs, with some wiring inside that connects everything together. But how does it all come together?

This simple flashing light circuit is powered with 6 volts/0.5A and has a low current consumption when the light bulb is off. The flashing frequency is set by only one capacitor.

Christmas lights themselves are a very simple circuit—in fact, they’re a great medium to learn about the flow of electricity.